# Yet Another Webster Begins



## CFLBob (May 20, 2019)

I spent entirely too long deciding what to build for my first IC engine and finally decided to go with the Webster while waiting for George Britnell to finish his plans for the Holt 75. 

Last weekend (11th/12th) was spent tracking down and ordering materials and I had it all by Friday.  I didn't get everything, but enough to do a really good start on the engine.  In particular, the parts labelled brass and bronze seemed hard to get small pieces of.  I need to find a good source for that.  

Found and ordered the two gears.  My usual source for metals has mostly been Online Metals, but I kept coming up with sizes and costs way beyond what I hoped to pay.  With eBay and a seller called USA Metal Online, I was able to save quite a bit over Online Metals for the 3/8 and 5/16" aluminum plates.  I bought several smaller pieces from Hobby Metal Kits, but probably saved the most looking for a flywheel blank.  The drawing says "CRS or Cast Iron", and the best I was doing was around $33 before shipping for a piece about 2" long and comfortably over 3.75" diameter of 1018 CRS.  This was both Online Metals and some eBay searches.  Then I ran into a different seller on eBay who had a chunk of what he called D2 tool steel at $18.75 including shipping.  I figured the important part was the specific gravity of steel vs. aluminum and bought the D2 blank.

Everything I bought is in and I'm going through the drawings to figure out how to do things, but there's one thing I did that's new to me.  The vinegar and salt solution for de-rusting steel really worked.  

Of the things I bought, the only thing that was rusty was the flywheel blank and it was totally rusted on the front, back and sides.  Since it's going onto the lathe to get cut, that didn't really matter, but I wanted to try that trick.  So into a plastic container, covered with white vinegar, and some salt because I didn't know exactly how much vinegar was in the container.  After 24 hours it looks like steel.  All the surface rust came off.  This thing was completely rust colored, without a single spot that was this color.  There was really no scrubbing to get to this point.  The rust just lifted off.  







My process is different than most of yours.  My mills are both CNC, so I either have to draw the parts up in 3D CAD so that I can create tool paths, or I have to get coordinates of every point on the drawings so I can enter points for holes, or start and stop points on straight cuts.  I won't be going very fast.


----------



## Brian Rupnow (May 20, 2019)

CFLBob--the Webster is the perfect engine for a first i.c. engine. Best of luck with your project, and if you need any help, give me a yell.---Brian


----------



## CFLBob (May 20, 2019)

Brian, one of the reasons I'm going this is that I've read you saying that it's the best starter engine.  

What I'm doing now is looking things over and deciding if there are things to change before I start cutting the parts.  

I have those jpegs you posted (over on the sideshaft IC thread, I think) of the valve seat cutter and the valve cages.  One of the pieces of metal I bought was a 36" bar of O1 tool steel 0.438" diameter.   I can make a lot of practice pieces until I get it right. 

Before I get to doing the Webster's valves and valve cages I want to figure out if I should use your cages or his, including whether I should use his 1/4" valves or the 3/8" valves the tool is designed for.


----------



## werowance (May 20, 2019)

Bob, could you take the dfx drawings and convert to stl?  is there software to do an automatic conversion? or can you even use stl for your cnc?


----------



## CFLBob (May 20, 2019)

werowance said:


> Bob, could you take the dfx drawings and convert to stl?  is there software to do an automatic conversion? or can you even use stl for your cnc?



Sort of.  I can import DXF into my CAD program (Rhino 5).  Once they're in Rhino, I convert the DXF to Rhino's native 3D model format, which involves a lot of drawing.   At the end, I have a solid model, though.   

I could absolutely use a .STL file, though.  I have to save my design as .STL for my CAM program.

I don't know of a way to convert DXF to Rhino automatically, or of some other utility that could convert the DXF to another 3D format.


----------



## Brian Rupnow (May 20, 2019)

Bob--when I made the Webster I had a terrible time getting the valves to seal. This was a matter of my own inexperience, not bad design on Websters part. I did make my valves exactly to the original drawing, so if the original drawing had 1/4" valves, then that's what I used. I do have two of those wonderful George Britnell valve tools, one for valves with a 1/8" stem and a 3/8" head and another for a valve with  3/32" diameter stem and a 1/4" head. You should absolutely read my build thread on it, because I learned an incredible amount of stuff when I built the Webster as my first i.c. engine, and I documented everything.---Brian
https://www.homemodelenginemachinist.com/threads/anybody-want-to-guess.7687/


----------



## ZebDog (May 20, 2019)

The Webster was my first I/C engine. I will be watching


----------



## Brian Rupnow (May 20, 2019)

Bob--My apology. The build where I had all the valve problems seems to have been the Kerzel hit and miss, which was my second? i.c. engine. I read all the way thru my webster build and didn't see much about valve trouble, but I then looked up my Kerzel build, and that one documents all the trouble I had with valves that wouldn't seal.
https://www.homemodelenginemachinist.com/threads/brian-builds-the-kerzel-hit-and-miss-i-c.10091/


----------



## CFLBob (May 20, 2019)

Thanks, Brian.   I've looked at much of the Webster build log before, but not the Kerzel.


----------



## cheepo45 (May 21, 2019)

I will be watching your build.
It's going to take you a while to whittle down that big chunk of tool steel to a flywheel!
 Scott


----------



## a41capt (May 21, 2019)

Bob,

I too am considering my first IC build and will be following along on your experiences. Looking forward to seeing how things work out for you!

John W


----------



## CFLBob (May 21, 2019)

cheepo45 said:


> It's going to take you a while to whittle down that big chunk of tool steel to a flywheel!



It's a lot of tool steel, which is a first for me and one of the many firsts in doing this engine.  I'm hoping to finish it in a day or so, but most importantly, I'm hoping to finish it with the same number of tools I start out with.


----------



## Brian Rupnow (May 21, 2019)

Bob--It's been a long time since I used the smaller George Britnell tool and I can't really remember which engine I used it on. I do however have a solid model of it and of the valve cage on the Webster. I pulled them both onto an assembly file, and it became apparent that the tool I have wouldn't work for the Webster valves. I have built over thirty engines over the last 12 years, and my memory is getting foggy on some of the engines I built at the beginning of my model building in 2007 or 2008.  The big trick of course is to keep the valve seat perfectly concentric to the "guide portion" of the valve cage, and that is what the "George Britnell tool allows you to do. In fact, I don't even try to cut the valve seat with a lathe operation. I turn the o.d., drill and ream the "guide" portion that the valve stem will fit into, and use an endmill to cut the opening that the port opens into. This leaves a sharp transitional edge where the valve seats, and the Britnell tool is inserted and turned by hand to achieve a seat of no more than .015" or .020" wide, after the cages have been inserted into the head. I make my valves with a 92 degree included angle, which gives a line contact at the top of the 45 degree seat. I press the cages into the head with a very, very  light press, and coat them with 638 Loctite before doing so. The cages will deform very easily, so it is much safer to cut the seat 24 hours after they have been Loctited and lightly pressed into place. Then I lap with 600 grit paste to achieve a good seal.


----------



## CFLBob (May 21, 2019)

To be honest, I'm not sure I understand all of that, Brian.

I was thinking that my choice is Webster's valve cages or yours (or are they George Britnell's?).  I don't know if they're interchangeable in size.  For sure, I don't understand how that part of the engine goes together.   That's somewhere down the road (sheet 10).


----------



## Brian Rupnow (May 22, 2019)




----------



## CFLBob (May 22, 2019)

Got it.  That helped.  

It looks like the Webster's valve cages are smaller versions of yours.  I think the 2.5 degree taper on the valve guide is cosmetic, since the taper doesn't mate with another part (the piston has a spring with a hole through the shaft for a pin to retain it).  They're machined as one piece, put in place, the hand-tool cutter used to cut and lap the valve seats, and then the port drilled in from the sides.


----------



## bigearl91 (May 23, 2019)

Good stuff, just finished mine and I am quite pleased with it. I learned an absolute heap from doing it and was pleased with the end result albeit not aesthetically pleasing, functional nonetheless. I'm sure you'll get the same satisfaction, especially when you get that first sign of life!

Enjoy it, the exhaust fix calls like the drums of Jumanji...

Coincidentally I had a horrendous time with the valves seating. And mesed up the blocks with silly error, making them all (and valve cages) 4 times.

Valves... 8. I definitely learned that patience, and plenty of english ale, is a virtue.

Edit: and read plans twice, measure twice, check plans again. measure again, cut once..

Earl


----------



## CFLBob (May 26, 2019)

Since it has almost been a week, I thought I'd post a little update.  

The start of the project has been in CAD and deciding what gets cut first.  It means importing the DXF files into Rhino and converting them from 2D flat drawings to 3D objects.  The first one I did was the base.  






This part doesn't really need to be made into a 3D part - I can drive Mach3 manually and cutout the plate, but I need to use the CAD to get all the locations of the holes in absolute XY coordinates from a reference and the start and stop points for every cut.  

After looking at sheet 3, I moved on to sheet 4.  Why?  I already have my vise mounted on the mill.  To cut out the plates, I'll have to take the vise off.  So I took the top part on sheet  and converted it into a 3D model.  But other than cutting it to length on the mill, there's just a few cuts and it doesn't really need the CAM either.  






I was closing in on finishing this part a little while ago when I realized the countersink I was counting on being 82 degrees was really 90.  Thankfully, I found werowance's post where he had the same issues and found the link to the set of countersinks at Lowe's.  They're near enough that I'll pop over there tomorrow to pick them up.  

The features on the front and back are done - the 1.000 x 0.500 deep bore on the back, the .625 relief on the front, and the four through holes (except the proper countersink).  Tomorrow, I'll do the four holes on the left side and the one 10-32 threaded hole on the bottom.   

I'll take a picture of it when it's done.


----------



## CFLBob (May 27, 2019)

I could use some input from those of you who have been down this road.  

I'd like to get some input on the spark plug to use and the ignition system in general.  The drawings call out a NGK CM-6 Spark Plug, which is apparently a Honda (motorcycle?) spark plug, and say to drill 0.348" to tap 10mm x 1mm pitch for that plug.  Then it says, "or drill 0.213 and tap 1/4-32".  

What fits that 1/4-32 thread?  

Should I be looking for mechanical points or is there an electronic system that people use?


----------



## Brian Rupnow (May 27, 2019)

The popular trend today is to use an electronic ignition system. S and S Engineering owned by Roy Sholl can fix you up with everything you need for about $100 Canadian, probably about $65 American. I personally use early Chrysler mechanical ignition points and condenser. I have a 12 volt coil that fits into it's own aluminum box, with an inline switch and leads which run to the engine with plug in ends. (I have about 18 i.c. engines)The nice thing about the 10 mm CM-6 sparkplug is that you can buy it quite cheaply from a generic auto parts store. The 1/4"-32 sparkplugs are "specials" and are sold by a number of people  for use in model engines. Electronic ignition systems are very fragile, and are not tolerant of bad grounds. If you get a bad ground it burns out the "hall effect sensor" and then you have to buy another. The old systems like I use are tolerant of anything up to and including an elephant stampede. If you need an old school wiring diagram, I will make one for you.---Brian


----------



## coulsea (May 27, 2019)

The CM6 plug is fine for a Webster, the 1/4 32 plug is common in the model aeroplane world and is perfect for an Upshur size engine. some of the cheaper Chinese ignitions can be a problem with burning out the hall sensors but I have had no problems with a rcexl model plane ignition, I have one ignition box with a hall sensor on each engine. naturally some will say that you didn't really build all of the engine if you didn't build the ignition and spark plug yourself.


----------



## stevehuckss396 (May 27, 2019)

CFLBob said:


> What fits that 1/4-32 thread?
> 
> Should I be looking for mechanical points or is there an electronic system that people use?



1/4-32 is the standard thread for a glow plug so model makers started making spark plugs with the same thread so a new engine could be started on glow plugs, dialed in, then switched over to spark ignition. Just one less thing to worry about when trying to get a fresh engine running. 1/4-32 spark plugs are available here. Also good quality 1/4-32 taps made in the USA.

http://www.miniaturesparkplugs.com/


Electronic ignitions can be fired using a hall sensor or points. One of my fellow MDMC members is building a Webster and is going to use the points from a 46-47 Nash or a 45-52 willy's because they are physically small. Roy sells a Barebonz CDI made specifically to be triggered by points. $45USD. That can be found here.

http://www.cncengines.com/ic.html


----------



## stevehuckss396 (May 27, 2019)

Brian Rupnow said:


> Electronic ignition systems are very fragile, and are not tolerant of bad grounds. If you get a bad ground it burns out the "hall effect sensor" and then you have to buy another.



You don't need to worry about that. You will be using points and they won't burn out. Also the CDI has a lot more energy than a normal 70's style system so it will net a better running engine. 

A cheap coil and condenser will run 30 - 35 bucks. May as well give 10 more for a good ignition that has enough energy to jump a half inch gap.

Not telling you what to do. Just telling you what I would do.


----------



## CFLBob (May 28, 2019)

Thanks everyone. 

I used to do all the routine stuff on my cars when the ignitions were points, coil and capacitor, back when periodically cleaning and gapping the plugs was required.  When electronic ignitions replaced that and made that maintenance less necessary, I learned a little about them but long since forgot.   As an electronics guy, that's more my "home field" than mechanical and designing one would be closer to up my alley. 

I think I'll get a CM-6 and a CDI.


----------



## Brian Rupnow (May 28, 2019)

Actually, the coil is the expensive part. They run $50 Canadian here. The points and condenser are about $16 total. The CM6 sparkplug costs about $17 or 18 dollars.


----------



## CFLBob (May 28, 2019)

The CM-6 plugs are $5.60 at the Advance Auto Parts store a couple of miles from here.  I didn't think to shop for the other parts.  

For the moment, I don't need the plug.


----------



## CFLBob (May 30, 2019)

My first piece is complete.  Well, the tap for the CM-6 plug isn't here yet, but that doesn't need the spot on the mill.







One hole broke through into the 1.000 x 0.500 bore - the bottom 4-40 hole in this view.  Should I just put something like a small setscrew in there, or will the actual, designed in screw be enough to seal that?   I believe this must be the combustion chamber.


----------



## Brian Rupnow (May 30, 2019)

Try it with just the screws that hold the valve body on first. Dip the screw that goes into that broke thru hole into some Loctite before installing it.  The trouble with putting in a set screw is that when the engine heats up and the vibration from running, that the set screw could work loose and fall into the combustion chamber, which is really bad ju-ju.


----------



## CFLBob (May 30, 2019)

What do you think about a dab of Bondo, or another epoxy in the hole?


----------



## Brian Rupnow (May 30, 2019)

You are getting into "Try it and see" territory. Remember--if it is in the combustion chamber it is going to see fire and pressure.


----------



## Chophead69 (May 30, 2019)

Please do not use bondo. If u need anything after u determined it does present a issue then use jb weld. And use a set screw if u like with it. It will not come out and it wont hurt ur project


----------



## CFLBob (May 30, 2019)

Chophead69 said:


> Please do not use bondo. If u need anything after u determined it does present a issue then use jb weld. And use a set screw if u like with it. It will not come out and it wont hurt ur project



Thank you.


----------



## CFLBob (Jun 5, 2019)

Broke a tap.  

I was working on the base plate and broke the tap on the first 6-32 hole I was working on.  

I think I'm going to get an annular cutter and then cut a plug to put into the hole.  I've never bought one of these, so I don't know how to size it.  If I wanted to cut out a quarter inch plug with the tap embedded, is that about 3/8 annular cutter?  I think they're sized by outside diameter, not inside.  The smallest I see is 7/16" anyway. 

Is there a better way to cut out the tap?


----------



## Brian Rupnow (Jun 5, 2019)

Try a 1/16" carbide end mill. That has worked for me in the past. There is a process using warm water with alum powder dissolved in it to maximum concentration. It will dissolve the tap but not bother the aluminum. You have to soak the part in a glass container of this liquid for a couple of days. I haven't used that method, and I see mixed reviews on how well it works.


----------



## CFLBob (Jun 5, 2019)

That's the same things I've read about the alum.  This piece is still full sized, so about 8x9".  Not sure I have anything big enough to soak it in anyway.   

The old trick of whacking it with a hardened nail punch worked.  The tap is out.  Before I give up on 6-32 and make those 8-32.  I'll try making them 50% engagement holes, which is a .116 bit vs. the .107 for 75% that I used. 

These are two different things being mounted to the base.  I can't tell what they are from the plans at this point but going to 8-32 is about 1/32 diameter bigger.


----------



## CFLBob (Jun 11, 2019)

It's a base plate.  









The drill press seemed to have too much slop in it because the countersinks look and feel rough.  I tried increasing the speed (cutter RPM) thinking it was chatter but that had no effect.  

I have the tool paths set for the sides.  This is set for a half inch EM, while I used 3/8 on the base.  Other than the fact that my half inch EM might not be as sharp, I don't see where it matters.  I do this kind of layout to save raw material.  




I also have the CRS for the Cylinder chucked in the big lathe.  Not sure which one becomes the next part.  

Onward.


----------



## CFLBob (Jun 27, 2019)

Time to update on progress.   Most of the shop time in the last couple of weeks was spent in the cylinder.  The prints say "12L14 Steel or Cast Iron".  I ended up buying 1018 Cold Rolled Steel on my shopping session, so that's what it's made out of.  

I spent some time trying to figure out how to transfer the marks for the four 4-40 screw holes, given tools I have, and eventually decided to chuck up the cylinder on my Sherline rotary table and drill the four holes as a bolt circle.  I did the tapping using my drill press as a vertical guide and then spotted and drilled the other two holes on the drill press.  






Overall view (on the Sherline/A2ZCNC mill) 






The cylinder isn't finished; it's about .010 short of the .873 recommended in the drawings.  I managed to break my telescopic gage for measuring the ID and am awaiting the replacement.  I still have to make the piston and lap that to the match the cylinder.  

If anyone is reading this and has experience with Viton piston rings, are those a good match to this engine?  From what little I know, they should be.  

I need to improve my fixturing before I cut the sides (tool path in previous post).  I need to make another couple of clamping spots.


----------



## Brian Rupnow (Jun 27, 2019)

Bob--I run Viton rings in all of my i.c. engines with great success. The only time not to use them is on a two cycle, where the piston has to pass over open ports in the cylinder wall. Use a 1/16" cross section Viton o-ring . Make the slot in the piston .094" wide  x .058" deep. You only need one ring.---Brian


----------



## te5745 (Jul 2, 2019)

Brian Rupnow said:


> Bob--I run Viton rings in all of my i.c. engines with great success. The only time not to use them is on a two cycle, where the piston has to pass over open ports in the cylinder wall. Use a 1/16" cross section Viton o-ring . Make the slot in the piston .094" wide  x .058" deep. You only need one ring.---Brian



How do you achieve the finish needed to not destroy the ring? Nickel plate?


----------



## Brian Rupnow (Jul 2, 2019)

No, just bore or ream to size and hone the cylinder with a 3 stone brake cylinder hone. I also add a bit of 2 cycle oil to my naptha gas, about a 50:1 mix .  I actually have worn rings out, although it is unusual. However, by the time a ring wears out the inside of that cylinder will be polished like glass.


----------



## CFLBob (Jul 7, 2019)

Just a weekly update.  My two side panels are cut out and ready for the holes to be drilled and tapped along the edges.  







Grabbed a picture while the mill was cutting out the two pieces, the last of five passes.  As you can see, I took the small piece, rotated it 90 degrees counterclockwise and moved into the space above the bigger piece.  This allowed a better fit of the two sides onto one piece of 5/16" plate that I have.  I cut the two out with a 1/2" EM, after drilling the holes and finishing them (three get tapped and three get reamed to final size). 

This got me thinking about using ball bearings in those three reamed holes instead of trickling oil from a cup mounted above the bearings.  I did that on my flame eater and I thought it worked out well.  That .250" hole is the size of the shaft for the two bearings I used last time, and they only needed a .375" hole.  There's tons of room to put ball bearings in all three holes.   

Does anyone have feedback on that idea?


----------



## Brian Rupnow (Jul 7, 2019)

Bob--I try to use sealed ball bearings in all of my engines. Most of the engines I build are open crankcase. The only recommendation I would make is that the plate in which the bearing sets should be at least 0.050" thicker than the bearing itself. I have tried using oilite bronze bushings and 660 bronze bushings. I have found that even with the greatest of care, my crankshafts are never 100% straight and true. The result of a "not perfectly true" crankshaft is that the bronze bearings very quickly wear out and become "sloppy", and then the engine rattles. There is enough "give" in a ball bearing that even if the crankshaft isn't 100% perfect, the inner race can "wobble" a bit while the outer race remains fixed in position.  This makes for a quieter, smoother engine.--Brian


----------



## CFLBob (Jul 7, 2019)

Thanks, Brian.  



Brian Rupnow said:


> The only recommendation I would make is that the plate in which the bearing sets should be at least 0.050" thicker than the bearing itself.



In this case, it's easy.  The plate is 5/16, .3125,  thick.  The bearings for the .500 diameter shafts require 0.750 holes and are 0.1562 front to back.  Almost half the thickness of the plate.  

I found my old record from when I bought the ball bearings for the Duclos Flame Eater and found I have two spares.  Those were for a .250" diameter shaft, exactly what I need now, and were .375 OD.  I needed two, bought four, and now I just need one.


----------



## CFLBob (Jul 11, 2019)

A couple of updates.  The first goes with a topic on Werowance Builds a Webster, where we've talked about a poor finish from Irwin countersinks.  I think most of us are reading both of these threads, but I'll put it here first.

When I did the two countersinks on the end of the long side plate, I used the exact same countersink as I used on the sample picture I posted before.  I did this on my G0704 mill with the countersink held in 1/4" collet instead of on my drill press in its Jacobs chuck.






The exact same countersink on my drill press did this:






I suspect it's because the drill press has wobble and unwanted movement.

My main reason for posting this is to update the side pieces themselves:






Where the 1/4" hole used to be is the ball bearing set I had.  I've ordered the ball bearings for the half inch reamed holes, but I need to buy a drill bit and reamer.  Those ball bearings require a 3/4" hole.


----------



## werowance (Jul 11, 2019)

i actually did 4 more countersincs in the valve block using the drill press this time and mine came out nice.  what I did is ran the drill press at full speed and kept an even steady preasure on it.  and that seemed to work better on mine.  I also tried in the mill with collet chuck and everything clamped or in the vice and had bad results on that.  I think it has to do with the speed and feed rate.  but just my guess.  more testing and practice for me to be sure.


----------



## werowance (Jul 11, 2019)

this hole,  where the cam and gear shaft goes,  it looks like a pressed in ball bearing?  or is it just where swarf spun around and is making an optical illusion on the finish?


----------



## CFLBob (Jul 11, 2019)

It is a pressed in bearing.  The bearing measured .3733 and I have a .374 reamer, so I drilled to the next size down (in 1/64ths) and reamed to the .374.  Then I used that woodworking bench vise that the piece is sitting on as a press by putting a piece of eighth inch aluminum over the bearing to get aluminum pushing stainless into aluminum all nice and square. 

Interesting we seemed to have opposite results with the drill press and mill.  

My drill press kinda sucks.  It's one of these Grizzly imports
https://www.grizzly.com/products/Grizzly-5-Speed-Floor-Radial-Drill-Press/G7946
and it seems to have too much slop for metal working.  I guess it's OK for wood, but it seems to move around and flex too much when you put pressure on the handle.


----------



## werowance (Jul 11, 2019)

ok, so I don't understand why a pressed in bearing there?  the gear/cam spins on the shaft that goes there right?  I thought only bearings in the top holes where the crank shaft goes.   a ball bearing setup would free up some friction there but not sure how you will mount the gear and cam on it like that.  would have thought a bearing pressed into the gear would be required or something.


----------



## CFLBob (Jul 11, 2019)

Maybe I'm using that term incorrectly.  I just pressed it in so that it doesn't fall out on me and I don't need LocTite.  

If my numbers are right, at room temp the hole in the plate is .0005 to .0007 bigger than the bearing so it needs to be precisely aligned when it's pressed in, but it's not a special fit.


----------



## werowance (Jul 11, 2019)

I guess I mean why is there a bearing in that place.  the plans show a .250 post pressed in there for the gear to spin on.


----------



## CFLBob (Jul 11, 2019)

That's a few posts up, #41. 

I kind of like ball bearings and asked for feedback.  Brian Rupnow said he likes them and tends to use them everywhere.  I'm putting ball bearings in both reamed half inch holes, too.


----------



## werowance (Jul 11, 2019)

ah ok,  now how are you going to keep the gear and its shaft fastened to that bearing?  E-Clips or something?  I agree the more rollers you can put in the better I think.  I managed to get them on one side of my connecting rod.


----------



## Brian Rupnow (Jul 11, 2019)

Bob--You may have screwed that up. As Werowance says, that hole in the sideplate is for a pressed in shaft that the gear spins on. The shaft is cantilevered---that is to say, there is no outboard support for the other end of the pressed in pin. If you want to use a bearing there, the bearing has to be pressed into the gear. You can not cantilever a shaft supported by a bearing in the sideplate. If you have already bored that hole out to take a bearing, you will have to make a stepped pin and press it into place.---Brian


----------



## CFLBob (Jul 11, 2019)

I was about to tell werowance that I hadn't gotten that far and now I'm even more sure I haven't figured it out, yet.  I'll take the bearing out and leave myself notes on the drawings.


----------



## CFLBob (Jul 13, 2019)

Brian Rupnow said:


> Bob--You may have screwed that up. As Werowance says, that hole in the sideplate is for a pressed in shaft that the gear spins on. The shaft is cantilevered---that is to say, there is no outboard support for the other end of the pressed in pin. If you want to use a bearing there, the bearing has to be pressed into the gear. You can not cantilever a shaft supported by a bearing in the sideplate. If you have already bored that hole out to take a bearing, you will have to make a stepped pin and press it into place.---Brian



It was easy to push the 1/4" ID, 3/8 OD bearings out of the hole, but the hole is 3/8 so the original approach is out the window.   

I don't understand how these things go together.  I ordered bearings for those 0.500 reamed holes, and since they require a 3/4" mounting hole, I bought a 3/4" chucking reamer and a 47/64 drill bit (1/64 under 3/4).  Both are unnecessary and just go in the tool box.  What I should have bought were bearings that accept the 0.313 crankshaft and fit in the 1/2" reamed hole.  I see them referenced on the last page of the plans - four of them.  He calls out four flanged bearings, so I assume one on each side of the two pieces.  
CRANKSHAFT BALL BEARINGS: 5/16" I.D. X 1/2" O.D X 5/32" THK., FLANGED
SOURCE: W.M. BERG: P/N B2-21 -OR- STOCK DRIVE PRODUCTS: P/N A 7Y55-FS5031
(4) REQD.

It looks like I'm supposed to take the exhaust cam (bottom right on sheet 8) and press fit that into the large gear on top left, sheet 9.  That assembly then goes on the camshaft, made of 1/4" drill rod (sheet 8, bottom, 2nd from right), which goes into the 1/4" hole where my small ball bearings were.  I don't understand what you mean by a stepped pin and what I'm pressing that into.


----------



## Brian Rupnow (Jul 13, 2019)

Bob--You have a detail of the cam shaft, which is given a diameter of 0.250". There is a hole in the one sideplate which is also given as being 0.250" diameter. This is not shown as being a press fit on the plans, so I am making the assumption that the cam shaft is held into the sideplate by applying Loctite to it before putting it in place. If you had already bored that .250" diameter hole out to something bigger to suit a bearing (which I thought you had), then your camshaft would have two diameters on it. One diameter to fit the hole which I thought you had made larger, and one to fit the cam gear which rides on the cam shaft . That is what you call a stepped pin.


----------



## CFLBob (Jul 13, 2019)

How could the cam shaft be held in the side plate with LocTite?  It wouldn't rotate.  I'm assuming the shaft rotates with the gear on it.  Does the gear rotate on the shaft?   

The exhaust cam (which gets the quarter inch shaft) goes onto the big gear - the drawing says to LocTite and press that cam onto the cam gear.  The cam shaft has an .063 hole drilled across it, .094 from one end.  I don't see where the instructions say what goes in that hole or why it's there.


----------



## stevehuckss396 (Jul 13, 2019)

From the Webster Drawings.

When making the CAM SHAFT, shoot for a press fit into the engine frame and a free rotating fit with the
CAM GEAR. Alternatively, you could use a set screw though the bottom of the SIDE FRAME to retain
the CAM SHAFT in it's bore.

Last weekend I helped someone get a Webster running. The camshaft was removed so we could reshape the lobe. It was installed using the set screw through the bottom of the frame method and the gear and cam lobe spun on the shaft.


----------



## stevehuckss396 (Jul 13, 2019)

More info from the drawings.

Press the bearing(s) and CAM SHAFT into the SIDE FRAME, slide on one CAM GEAR WASHER,
the CAM GEAR ASSY (with the CAM pointing towards the frame) followed by another
washer, and secure with a cotter pin. Be sure that the gear spins freely on the shaft - adjust
as necessary


----------



## CFLBob (Jul 13, 2019)

Thanks, Steve.  

I can make a little stepped pin/camshaft like Brian suggested, but the important part here is the CAM SHAFT is motionless, and the CAM GEAR, with the EXHAUST CAM mounted on it spin on the shaft.  A cotter pin keeps it from sliding out of place.


----------



## CFLBob (Jul 16, 2019)

In the very first post I put up on this build, I talk about the blank I picked up to for the flywheel.  To save you the time, the short version is I came across a blank that was half the price of the cast iron or cold rolled steel the plans call for and thought I'd try it.  The blank is D2 tool steel, which I'd never even heard of.  

I started machining it this week while waiting on the ball bearings and a few other things I've ordered.  

While facing it, I found it was very easily heat treated.  A .005" cut turned the chips golden or amber colored.  A .010" cut turned them cobalt blue and extremely brittle.  Just touching them cracks them.  So while it was slow going on my 1HP Seig lathe, I faced it and then cut it to diameter.  Now it was time to part off the extra length and get the blank down to the proper size to finish.  

This is where it got really involved.  I started off with a parting tool that was 3/32 wide.  I quickly realized that was too wide and didn't seem to be cutting well enough, so I switched to a 1/16 wide tool.  That was doing better.  Again, I realized that it was bogging down but if held a hacksaw in the cut and let the cutoff blade just trim off the shoulders of that cut, it went pretty quickly.  That worked for about the first half inch of the 1-7/8" inch I had to cut. 

Then I realized the hacksaw wasn't cutting.  The teeth were worn away.  I switched the blades and made some progress.  Then I noticed the cutoff tool was losing its shape; instead of the Tee shaped cutting edge, it was wearing to a point.  I turned it end for end and kept going. 

Let me cut out more details, but say it probably took a good six hours of fighting to cut off the extra half inch thickness.  Plus an hour running up to the two local hardware chains (True Value and Home Depot) looking for carbide tipped hacksaw blades.  The eventual solution was a carbide tipped blade for my reciprocating saw.  

https://www.homedepot.com/p/Diablo-...ng-Reciprocating-Saw-Blade-DS0608CF/205426155







It's interesting material to work on.  I suspect that forming the flywheel is going to continue to be an adventure.  I probably would have been better off paying twice as much for a piece of cast iron.  I'm still thinking of doing that.


----------



## Brian Rupnow (Jul 16, 2019)

Bob--1018 cold rolled steel, brass$$$, bronze$$$ or cast iron will all work well for flywheels. By the time you get the sides of that piece hogged out you will have cost as much in cutting tools as you would have spent for a more machineable steel.


----------



## minh-thanh (Jul 16, 2019)

Hi  CFLBob !
More option :






I often use this flywheel on my engines .


----------



## CFLBob (Jul 16, 2019)

Brian Rupnow said:


> Bob--1018 cold rolled steel, brass$$$, bronze$$$ or cast iron will all work well for flywheels. By the time you get the sides of that piece hogged out you will have cost as much in cutting tools as you would have spent for a more machineable steel.



I was thinking it behaves like some stainless I cut once (on my Sherline).  It cold works while you're cutting it.  I looked it up and it does contain chromium like stainless, but 12% and most stainless I've looked at is higher chromium. 

I think if I add in the cost of the cutoff tool I broke off and the saw blades I bought, I've already spent more than what I saved buying this disk.


----------



## CFLBob (Jul 16, 2019)

Hi, Minh Thanh.  Thanks!  Are those scrap pieces you had or found?

You know, Webster said his flywheel was made from a bar bell weight he bought at Walmart.  That might be the cheapest way.


----------



## minh-thanh (Jul 16, 2019)

Hi CFLBob !
It's not  scrap pieces .
Shop selling iron pipes, they cut as required,


I think it's much cheaper than the price of a bar bell weight .


----------



## CFLBob (Jul 16, 2019)

I'll have to look for that around town.


----------



## Brian Rupnow (Aug 10, 2019)

Bob--What is happening with this build? You haven't posted for a while.---Brian


----------



## CFLBob (Aug 10, 2019)

Thanks for asking.  I haven't spent a few hours in the shop in 10 days.  

Last Thursday, we got hit by lightning.  Either the house, my backyard oak tree or something very close, and I've been finding and fixing broken or blown out things since then.  I still haven't gotten our tankless water heater running properly, but it has an emergency backup mode that gets us hot enough water to shower.  It took out my air conditioner's thermostat, my internet cable modem, my WiFi router, and really just a lot of stuff scattered around the house.  The air conditioner isn't quite "life or death" but in August, it's pretty close to that level, and we called the repair guys first.  If anyone has been through this, you know the pattern of damage is that there is no pattern, it appears to jump all over, blowing some things and not touching others.  

The last thing I did was decide to put the tool steel flywheel aside and bought a disk of 1018.  I turned it to size and then stared facing it down to be a flywheel.  I made one facing cut so far, .025 out of the .125 I need to take off.   I was going to post an update and then the lightning happened, so let me put this here.






I'm hoping to get caught up enough that I can spend more time in the shop.  So far, it has only cost about $750 out of pocket - which isn't even my homeowner's insurance deductible.


----------



## Brian Rupnow (Aug 10, 2019)

I had one of those old gigantic satellite dishes when I lived in Hillsdale. It got struck by lightning, which took out everything from the satellite dish to the television. It was covered by insurance, but when the lightning struck we were all in the TV room watching something and it damn near scared us all to death.


----------



## CFLBob (Sep 11, 2019)

Strange I finally get around to posting the flywheel almost exactly a month to the day since the last post.  

I have one more operation to do on the lathe, to bore it on axis for the 0.500" hole.  The print says to bore 0.188 deep but my gear's hub is taller than that, so I need to understand how this goes together.   That is, should I bore it to the depth of my gear or make it like the print?  If I do the first, the gear is closer to the flywheel, and vice versa.






I still spend a lot of time working on recovering from the lightning strike.  Hurricane Dorian came close and several days were taken up by the storm.  Putting up and then removing the shutters and so on.  Thankfully, it passed well offshore after destroying the Bahamas.  We got just over 1" of rain and winds to something like 56, which adds up to nothing.


----------



## Brian Rupnow (Sep 11, 2019)

If you look at sheet #5 of 21 and  #9 of 21 on the downloaded internet plans, you will see a picture and a detail of the flywheel and the gear hub which fits into the counterbore in the end of the flywheel hub. If you made the flywheel as per the detail on sheet #5 of 21, the hub should extend 3/16" beyond the side of the flywheel and be .625" diameter. You are being asked to put a hole in the end of the hub 1/2" diameter x .188" deep. This counterbored hole will receive the hub of the gear. If you already have the gear, then try and bore the 1/2" diameter hole about 0.0005" undersize so the gear hub will be a press fit into the hole. If you aren't comfortable working to that small a tolerance, then make the hole a true 0.500" diameter and use Loctite when you attach the gear.


----------



## CFLBob (Sep 11, 2019)

My flywheel is within "a couple" of thousandths of the those numbers - .625 diameter hub that's 0.188 beyond the rim of the flywheel on both sides.  It's currently just through-reamed to 0.313 (5/16).  The half inch bore is the last operation before I move it to my rotary table.  

What was confusing me was my gears.  I ordered the parts on the drawing from Stock Drive Products.   I've had them for months.  I had always thought we used the gears as bought, but when I compared them to the sheet 9 drawings, they didn't match.  I thought I pushed the hub of that small, 24 tooth gear into the 0.500 by 0.188 hole I bore, and noticed it was too long.  It's not just too long, it's too big in diameter. That hub on my gear is 0.655, larger than the .625 flywheel hub I thought it pressed into.  Look at this clip from sheet 9.  






Tonight, I went back to SDP and found that the part numbers I ordered match the drawing.  I downloaded the .stp files, measured the drawing and that matches my parts.  Since this drawing page says "machine for light press into flywheel," it must mean I machine the gear to these dimensions.  The other gear gets machined as well.


----------



## Brian Rupnow (Sep 12, 2019)

Use an appropriate size shaft,  Attach the gear to it with a grub screw (set screw). Set it up in your lathe and turn the hub to the correct diameter and length. (Make sure the grub screw is short enough that it doesn't get hit by the cutting tool.)


----------



## CFLBob (Sep 12, 2019)

Brian Rupnow said:


> Use an appropriate size shaft,  Attach the gear to it with a grub screw (set screw). Set it up in your lathe and turn the hub to the correct diameter and length. (Make sure the grub screw is short enough that it doesn't get hit by the cutting tool.)



Roger that.  I should be able to handle that.  I have a handful of extra set screws.  

"First things first" is I'm going to finish that bore and finish the flywheel.


----------



## CFLBob (Sep 14, 2019)

With the bore complete (.500 by 0.188 deep) and just before I take it off the lathe to mount on the rotary table.  

That's another one of those tasks that takes about 5 times longer to set up than to do. 




Should be able to get 'er done tomorrow.  The parts for my next lightning fix won't be in for a few days.


----------



## werowance (Sep 16, 2019)

looks good Bob,  nice n clean cuts


----------



## CFLBob (Sep 16, 2019)

Minus Dykem and plus a few holes.


----------



## Brian Rupnow (Sep 16, 2019)

Nice flywheel Bob.---Brian


----------



## werowance (Sep 17, 2019)

looks good.


----------



## CFLBob (Sep 17, 2019)

You know that saying, once you see something you can't un-see it?  The flywheel reminded me of the '70s Saturday Night Live puppet, "Mr. Bill".  





Now I see that puppet every time I see the flywheel.


----------



## Shaun free (Sep 17, 2019)

D2 steel is a semi stainless air hardening tool steel. It is designed to be an abrasive resistant steel.If you are causing enough heat machining it it will harden and be harder than your HSS. You will be better off using carbide and cutting deep and fast than slow and thin.


----------



## CFLBob (Sep 17, 2019)

Shaun free said:


> D2 steel is a semi stainless air hardening tool steel. It is designed to be an abrasive resistant steel.If you are causing enough heat machining it it will harden and be harder than your HSS. You will be better off using carbide and cutting deep and fast than slow and thin.



Exactly what I experienced.  If I turned .005" (radius), the chips came off with hardly any color change; maybe a light amber color.  If I cut .010, they came off deep blue and brittle.  

My lathe just didn't have the power to cut it as deep and fast as it "wanted".  It's only one HP.


----------



## CFLBob (Sep 17, 2019)

Brian, Werowance or someone who has done one of these.  

I'm making the crankshaft on sheet 5, and knocking off the little parts there.  I made the "Crankshaft Spacer" from a piece of half inch 4130 I had.  I got a length of 5/16 rod for the shaft from SDP (the place I got the gears from), cut it to length, faced and made the ends pretty.  I haven't cut the 1.250 x 0.500 x 0.25 thick bar.  Does the Crankshaft Spacer go in the half inch hole in that bar?  Is that silver soldered in place?  

I'm trying to understand what I'm reading in the build threads about the crank shaft and counter weight web.  That goes on the end of the shaft that's shown with nothing on it, right?  I'm having a hard time seeing how this goes together, if there's something on both ends.  Silver soldered on both ends.  

I started on this part:






and then noticed that it's optional.  I gather these are for the crankshaft in the two side plates, right?  I bought ball bearings for those spots.


----------



## Brian Rupnow (Sep 18, 2019)

Bob--the spacer is exactly that.--a spacer. It doesn't attach to anything. It fits between the small gear on the crankshaft and the left hand sideplate on the engine. For answer to most of your questions see posts #47 thru 51, post #98, 264, and 306 on the following thread.
https://www.homemodelenginemachinist.com/threads/anybody-want-to-guess.7687/


----------



## werowance (Sep 18, 2019)

on my spacer, I didn't even follow the plans because after the gear press in, slightly thicker fly wheel etc the spacer would have been to thick.  I left that for near last things to do.  once I had everthing somewhat assembled and could rotate and such.  (flywheel not pinned at this time) then I measured and cut a spacer to take up the dead space between the gear on the flywheel hub and the bearing on crank support.  I just used feeler gauges to get the right thickness.   I really don't think its overly critical (but do put one in) because the points cam and the crank web/throw on the other side keep things in place.  and I just used a piece of scrap brass for mine.

then next are you going to use bronze bearings instead of roller bearings?  for some reason I thought you were going with rollers?  if so the part you have pictured is not required.  I got mine on ebay.  not the cheapest bearings but I do prefer rollers if possible.


----------



## CFLBob (Sep 18, 2019)

werowance said:


> then next are you going to use bronze bearings instead of roller bearings? for some reason I thought you were going with rollers? if so the part you have pictured is not required. I got mine on ebay. not the cheapest bearings but I do prefer rollers if possible.



You remember it right.  I bought ball bearings.  The ones called out on sheet 21.


----------



## werowance (Sep 18, 2019)

on the crank throw counter balance,  here is how I did mine.  I cut a disk 1.75 because the plans call for a radius of .875 on the tip of the crank throw.  I drilled the center hole and silver brazed it to my crank shaft.  I then mounted it in my rotary table with er32 chuck mounted to it.  I centered it with my mill head and then tramed it to drill the rod pin hole.  I then trammed it over and cut the 2 sides leaving a counter balance at the bottom. - pictures will probably explain that better.  I didn't make a bolt on counter balance or anything.  and the plans don't call for a counter balance but is a nice feature I think.  the counter balance section starts right at the center line of the center hole drilled for the crank shaft.  the rod pin or shaft that the rod connects to on mine is larger than the drawings because I used roller bearings on that as well.  2 little tiny rc bearings pressed into the rod.  unfortunately I had to use brass bushing on the rod / piston wrist pin side of things because I couldn't find roller bearings small enough on that end.

first pic is the disk brazed to the shaft  - not my best brazing job either.





next 2 pics are after its finished











third pic is what the plans called for


----------



## werowance (Sep 18, 2019)

rod showing the ball bearings - and I believe I keep saying roller bearings but that's just a bad habbit.  they are really ball bearings so if you see me say roller - I mean ball.  the blue side of the rod are the 2 ball bearrings.


----------



## CFLBob (Sep 18, 2019)

It's hard to describe how messed up I was.    

Let me show you:





There's a raised area on the shaft side of the that piece you made into a counterweight, in the red oval.  It's .031 thick.  There's a rim on the bearing that's also .031 thick (on the right).  So I thought that's where that bearing went.  If you don't look closely, the diameters match.  The bearing is 0.500" diameter except for that lip. 

The end views of that piece match.  You posted the view looking at the shaft from the far side, let me post the view looking down the shaft at that piece. 





We see the 0.313 is the shaft seen end on.  That 0.500 circle, (.031 tall) is a mystery, though.  Again, I thought it was that optional bearing, but that's 0.563" diameter.  The lack of hidden lines in the side view wipes that out, too.  It's just a raised area on the crankshaft side of that piece.

And I was looking at the crankpin grease cup on sheet 13 of the drawing to go in the top hole of that piece, where you have a threaded rod.  I don't even see where that comes from.  I mean, did you change dimensions on whatever that drives?


----------



## werowance (Sep 18, 2019)

on that raised bit (.031 shim), here is how I handled that - and also how I originally planned to do it but didnt.  when brazing mine, I had extra silver braze on the back side.  I turned that lump back down to be the .031 shim.
the plans do show it as a cut part of the whole crank throw but a washer will suffice just fine.  and is easier to adjust thinner or make wider as necessary. 

what I originally planned on doing is simply making a shim (small washer) out of brass to adjust with if need be. and also if needed a shim (washer) on the rod dowel since I used ball bearings I didn't need that oiler cup on the rod dowel so that helped also.  the roller bearings for the rod are not even mentioned in the plans as an option.  that was just something I changed myself.  made life a lot easier.  I can get you the rc car bearings part number I used if you need or want them.

now also on that .031 shim (washer) - the thing to be carefull about is that you want the shim to contact the inside race of the bearings and not the outside race, so all you need is just something there to prevent the crank web from rubbing the outside race which is stationary and thus will score and mar.


----------



## werowance (Sep 18, 2019)

CFLBob said:


> And I was looking at the crankpin grease cup on sheet 13 of the drawing to go in the top hole of that piece, where you have a threaded rod. I don't even see where that comes from. I mean, did you change dimensions on whatever that drives?


  on that part the crank pin is solid because I didn't do a grease cup - used ball bearings.  here are the ball bearings I used - copy and paste from my ebay order.  came in a pack of three, only 2 are needed installed side by side.  Team Associated 8682 Bearings, .250 x .375 x .1 inches RC10F6

now looking back on my earlier post I said the crank rod pin was bigger,  its actually smaller.  .250 to fit the inside of those ball bearings.  the outside of the ball bearings fit the rod as per plans.  then on the other side of the rod you will still have to use bronze or brass bush.


----------



## werowance (Sep 18, 2019)

sorry for all the replies, but here is another way I deviated.  making the crank throw and brazing it to the crank shaft - the tip of the shaft that would normally go in the throw - I made it smaller and also drilled the hole in the throw smaller as well.  this way I could reliably keep the throw in the correct position when brazing it.  the crank shaft did not protrude all the way through the throw so that I could puddle a little silver braze in the recess.  I did the same process for the rod dowel going on the throw.  also beveled the sharp edges on the throw and the rod where silver braze would go so it could "get in the cracks" so to speak...  a rough quick / exadurated drawing of what I'm talking about below


----------



## CFLBob (Sep 20, 2019)

Had some time this afternoon to finish the gear/flywheel assembly.  






It was a snug fit until I took a high spot by turning with a metal file.  I think it's maybe a .0015 fit.  I think it's red Loctite time.


----------



## werowance (Sep 20, 2019)

nice,  what material is your gear?


----------



## CFLBob (Sep 20, 2019)

I didn't make it.  I bought it from Stock Drive Products, number on the drawings.  It's steel of some sort, it felt machined pretty much like 1018.


----------



## werowance (Sep 20, 2019)

well, that should be a long wearing gear.  great job on the flywheel.


----------



## CFLBob (Sep 20, 2019)

Thanks.  I checked my powder and don't have anything like that neat black wrinkle you used.  I need to order some.  First, I need to get that flywheel finished better and shined up.


----------



## CFLBob (Sep 21, 2019)

Brian Rupnow said:


> Bob--the spacer is exactly that.--a spacer. It doesn't attach to anything. It fits between the small gear on the crankshaft and the left hand sideplate on the engine. For answer to most of your questions see posts #47 thru 51, post #98, 264, and 306 on the following thread.
> https://www.homemodelenginemachinist.com/threads/anybody-want-to-guess.7687/



Brian - hoping replying to you pings this so you know this is here.

I was talking with a friend about this, while trying to decide if I use your triangular sector or werowance's semi-circle, and he asked me one of those questions that makes you go hmmm.  

Instead of adding weight to balance the system, what about drilling out holes in the rim of the flywheel to reduce its weight?  Something like this, 3/8 holes in the thick part of the rim.   I've never seen it done.  I know something about computing the moment of inertia and that's what matters, but I don't know how to design this and figure out how many holes, for instance.






Any thoughts?


----------



## Brian Rupnow (Sep 21, 2019)

You can do it that way, but in my opinion it makes an ugly flywheel. And if you get it wrong, there is no way to fix it.  I recommend doing the same as Werowance and myself, because we know it works. There is a scientific way to calculate the mass of the counterweight, but it is fairly complex and you don't have a gram scale to do it anyways.


----------



## CFLBob (Sep 21, 2019)

I agree with you on the looks.  It's pretty unsightly.  I think I'll be doing your approach.


----------



## CFLBob (Sep 27, 2019)

I'm roughing in the piston now, and based on what I was reading over at Brian's Vertical Hit and Miss engine, 
https://www.homemodelenginemachinis...hit-and-miss-engine.31370/page-14#post-328819

I thought I'd check into cast iron rings for this.  The Webster drawings says:
PISTON RINGS - 3/32" X .875"
(2) REQD.
SOURCE: OTTO GAS ENGINE WORKS
(410)-398-7340
2167 Blue Ball Rd
Elkton MD 21921-3330
http://www.dol.net/~dave.reed/otto.html

The website doesn't work so does anyone know if Otto Gas Engine Works is still around?  Where can I get these?


----------



## werowance (Sep 27, 2019)

same guy as listed in the drawings,  he just changed his website.   below is updated contact info.  he was quick to respond to my emails.

Dave Reed 
Otto Gas Engine Works 
2167 Blue Ball Road 
Elkton MD 21921-3330 USA 
phone 410-398-7340 
http://www.ringspacers.com 
http://www.pistonrings.net


----------



## werowance (Sep 27, 2019)

this is his email address to.
Dave Reed <[email protected]>


----------



## CFLBob (Sep 27, 2019)

Thanks for the quick reply.  Email to be sent once I post this.


----------



## minh-thanh (Dec 26, 2019)

CFLBob !
What is happening with this build?


----------



## CFLBob (Dec 27, 2019)

minh-thanh said:


> CFLBob !
> What is happening with this build?



@minh-thanh - thanks for asking and bringing this back up.  I got tied up working on things damaged by the lightning strike and didn't get back into the shop until last week. It has taken me a while to remember where I was.  The lightning was back in August and stuff still was dying until a few weeks ago - and I hope I've replaced the last of the blown up things. 

I have questions about fitting the piston that I was coming here to post about when I saw your post.






I got this brake cylinder hone because I could feel little ridges on the inside of the cylinder wall with my fingertip.  They're better but I can still feel them.  The piston is very close to fitting but sometimes acts like it fits better when I rotate it a bit as I try to get it into the cylinder.  I think I'm within the last thousandth of being the right size. 

My question is that I don't really know how to fit a piston with rings.  Without the rings in, how loose should it be? 

All I know is that the drawing says the piston should be 0.873 while the cylinder should be 0.875 lapped.  I think the cylinder is 0.876 or .877 now, with the bumpiness and not being lapped.  The piston is either 0.873 or very close.  

Both of them are very close and this is not the time to be rough.


----------



## werowance (Dec 27, 2019)

on mine,  the rings fit just right with .876 which is where my cylinder was at after laping.  I didn't use a hone on mine,  just an aluminum lap with some 600 then 800 then 1000 grit laping compound I bough on ebay,  came in what looks like what my wifes skin cream comes in, little white plastic jars smaller than a baby food jar.  when I inserted the ring into the cylinder without the piston to see what the gap was,  there was hardly any gap at all.  the inside of the cylinder was smoothe and shiny unlike what a chevy 350 would look like after coming from the machine shop that was honed rather more like what a cox model aeroplane engine would look like.  maybe not that smoothe but close.  but the fact that at .876 I had hardly any gap on the ring I bet it would have still ran if I were at .877 or .878 even, really cant say for sure but I felt better when I saw almost no gap.


----------



## minh-thanh (Dec 27, 2019)

Hi CFLBob !


CFLBob said:


> I got this brake cylinder hone because I could feel little ridges on the inside of the cylinder wall with my fingertip.  They're better but I can still feel them.  The piston is very close to fitting but sometimes acts like it fits better when I rotate it a bit as I try to get it into the cylinder.  I think I'm within the last thousandth of being the right size.
> 
> My question is that I don't really know how to fit a piston with rings.  Without the rings in, how loose should it be?
> 
> ...




With the cylinder in all the engines I did:
I often try to make it seem "straight" and shiny - like polishing (I think I cannot afford and have the tools and machines to make it to the level of the oil's molecule )
I call it: seemingly straight because I know for sure the cylinders I've made, none of which are perfectly straight, A little taper at TDC no problem
With a piston without rings: it moves smoothly within the cylinder
 piston with rings: I can push it in the cylinder with my fingers with a moderate amount of force
Rings and cylinders: I usually choose a clearance of 0.02 mm (cylinder and ring made of cast iron)
A little information, hopefully useful !


----------



## CFLBob (Dec 27, 2019)

minh-thanh said:


> With the cylinder in all the engines I did:
> I often try to make it seem "straight" and shiny - like polishing (I think I cannot afford and have the tools and machines to make it to the level of the oil's molecule )
> I call it: seemingly straight because I know for sure the cylinders I've made, none of which are perfectly straight, there's a little bit of TDC no problem
> With a piston without rings: it moves smoothly within the cylinder
> ...



I think that's useful.  When I measure with the telescoping gages and calipers, it seems like the thousandths digit varies more than I'd like in both the piston and cylinder diameters.  Maybe .002 or even .003.  It has made me more aware of temperature variation while working and not over or undercutting because of the size of the work changing.  It makes me cautious about thinking I've got everything exact.


----------



## CFLBob (Dec 28, 2019)

I wrapped my brake cylinder hone in 150 grit sandpaper and ran the lathe for a while.  I could still feel the roughness. 

Then I went to 220, 320 and 400 sandpaper.  I can still feel the roughness, just a lot less rough than when I started.  I took this picture.  I manipulated it a little to try to bring out the differences so the surface is better than this looks but it's definitely not "like glass."  I guess it comes down to how fine a roughness I can feel.  I've read we can feel .005", but I sure hope these ripples are smaller than that.  150 grit is .0067", so it should be smoother than that, all the way down to 400 that's .0025"






The offset circle at top is the center of my lathe chuck.  Just left of bottom dead center in the cylinder, you can see what looks like a bump but is one of the chuck's jaws.


----------



## minh-thanh (Dec 28, 2019)

CFLBob !
  if the graphite piston lasts long in the cylinder of the flame eater engine you have made, you can make the cylinder surface like that it will be fine.
Don't worry too much about the cylinder surface being shiny or gray, some members have advised me: "It's whatever you feel comfortable with" !!
  The flame eater engine is much harder to run than 4-stroke engines, you have succeeded with it there is no reason why you are not successful with this engine  .


----------



## CFLBob (Dec 29, 2019)

minh-thanh said:


> if the graphite piston lasts long in the cylinder of the flame eater engine you have made, you can make the cylinder surface like that it will be fine.
> Don't worry too much about the cylinder surface being shiny or gray, some members have advised me: "It's whatever you feel comfortable with" !!
> The flame eater engine is much harder to run than 4-stroke engines, you have succeeded with it there is no reason why you are not successful with this engine .



The flame eater still runs and that's my encouragement.  

I did some measurements on the cylinder last night and I think it might be 0.878" diameter at the end that gets the spark plug.  The piston is roughed out at 0.874.  I haven't cut the slots for the rings, because the cylinder is on the lathe.  

I think I'm going to keep going.  I have enough steel to make another cylinder, but I'd rather not unless I really need to, and I'll find out once it's built.


----------



## minh-thanh (Dec 29, 2019)

CFLBob said:


> The flame eater still runs and that's my encouragement.
> I have enough steel to make another cylinder, but I'd rather not unless I really need to,


Do not be too important the diameter of the cylinder, if the diameter of the cylinder is larger or smaller, just make the piston according to the new size of the cylinder. It is always easier to make a new piston than to make a new cylinder.
Just making the cylinder as you were with the flame eater engine is fine .


----------



## CFLBob (Jan 19, 2020)

I spent some time figuring out what to do, since I suspect the cylinder might be too big now.  I had piece of aluminum bar, just about the 0.873 final size about 2.5" long.  I thought I'd turn down about half the length down to 0.5" diameter and chuck it in the lathe, then before machining the features inside the piston, I'd put the rings on it and see how the piston feels.  After this machining and then running a green Scotchbrite on the cylinder to take off any burs, the piston falls in the cylinder, but it doesn't fall "fast".  That seems pretty good.  I think the goal is that when the rings are on, I should need to push my piston handle to get it fall, right?  






I don't know how to get the piston rings on.  Those are the ones that Webster recommends in the drawing, 3/32" X .875" from Dave Reed at Otto Gas Engine Works.  Since the OD of the rings is about .002 more than the OD of my piston and they fit snugly in the slots I cut, I have to "stretch" them to get them into the rings and I'm not having much luck.  I'm trying to be gentle and not bend them.  Or not bend them too much.  

How do I get those piston rings in there?


----------



## Brian Rupnow (Jan 19, 2020)

Coat piston and rings with 30 weight oil. Set ring on top of piston and gradually work one end of ring down into top groove. Then work as much of the ring as you can (about half of it) down over the top and into the groove. Hold your breath. Push the remaining part of ring out so that it is resting on the land above the groove. Taking great care not to notch the piston with the sharp inside corner of the ring, work that part of the ring down so it snaps into the groove. I then put the second ring onto the piston from the other end. This avoids having to work second ring past first ring installed. This scares me right to death every time I do it.---Brian


----------



## CFLBob (Jan 19, 2020)

Thanks, Brian!


----------



## aka9950202 (Jan 20, 2020)

I run my engine with 1 piston ring.  There are 2 slots as per the plan on the piston. My rings all snapped when trying to install the second ring. I  had made 6 rings in total.

Good luck with your model i hope you have better luck than I did. 

Cheers, 

Andrew in Melbourne


----------



## CFLBob (Jan 20, 2020)

Well, thanks to Brian's suggestion, I got the rings in the piston but can't get the piston into the cylinder.  The rings appear to stick out more in some places than others.  Not loose, that I can tell.  Possibly bent?  






Considering they're standing well above the piston, it makes sense I'd have troubles getting the piston into the cylinder.


----------



## Brian Rupnow (Jan 20, 2020)

Next amazing trick--You should have put a 20 to 30 degree lead angle on the end of the cylinder opposite the head.(That is total included angle). That way with 30 weight oil, prayer, and tap-tap-tap on end of connecting rod, the lead in taper will compress the rings as the piston slides in. (piston, wrist pin and con-rod must be assembled first). If you haven't put the included angle on the cylinder, you can try using a small gear clamp as a ring compressor and put the piston in from the other end (although I haven't done that--too much chance of breaking a ring).


----------



## fcheslop (Jan 20, 2020)

Make a piston ring clamp, just some shim or beer can and a hose clip
Iv still snapped a few rings though
You wont get an accurate measurement of the bore using vernier caliper as the jaw overlaps so you measure a chord
https://www.machinemart.co.uk/p/cht257-piston-ring-compressor/


----------



## Brian Rupnow (Jan 20, 2020)

Bob--did you turn the ring grooves on the piston to the diameter recommended by the ring supplier? The rings should also be a sliding fit into the grooves in the width dimension. Not a sloppy fit, but not tight either. I found on my sideshaft engine that the rings were about half a thou over width, so I spread a bit of 600 grit aluminum oxide paste on a sheet of glass and lapped both sides of the rings, so they would be an easy sliding fit into the grooves cut by my 3/32" parting off tool.


----------



## CFLBob (Jan 20, 2020)

I have a 45 degree lead angle there, as the drawing says, "SMALL 45 CHAMFER TO EASE RING COMPRESSION AND PISTON INSERTION," but I didn't try tapping.   

As you can see, this isn't the regular Webster piston.  I was concerned the cylinder was too big for the piston, and machined a handle onto it.  I was going to check to see if I needed to make a new piston with as little work as I could get away with.  If the piston looked like it would work, I'd do the details in the piston.


----------



## CFLBob (Jan 20, 2020)

fcheslop said:


> Make a piston ring clamp, just some shim or beer can and a hose clip



Why not just the hose clamp?  It seems all the shim stock does is spread the compression a little.


----------



## Brian Rupnow (Jan 20, 2020)

Bob--Truth is---If your piston has rings on it, you can safely make the piston .002" less in diameter than the cylinder. The expansion of the rings will seal anything trying to get past the piston. I took a look at the chamfer on the cylinder called up on the original Webster drawing, and in my opinion it's too steep an angle. The rings will just cut into the end of the cylinder, raise a burr, then break the rings if you try to force things. I stand by my 20 to 30 degree included angle about 5/16" deep into the cylinder, and lots of oil when trying to get the piston in.  After turning the taper, carefully remove the abrupt inner edge of the chamfer by using some 200 grit carborundum paper--don't let it grab your finger and twist it off. I do this under power, but damned carefully. The gear clamp you show has a dirty little secret--it stays flat in the area next to the screw.  It will uniformly squeeze the ring--except in the area close to the screw. In that small area, the rings will still stick out far enough past the edge of the piston to break the ring.


----------



## CFLBob (Jan 20, 2020)

Thanks, Brian.  I can modify that to be more like 20 or 30.


----------



## werowance (Jan 21, 2020)

for what its worth,  i used wider than the ring zip ties to compress my rings so i could slid the piston into the cylinder.


----------



## CFLBob (Jan 21, 2020)

werowance said:


> for what its worth,  i used wider than the ring zip ties to compress my rings so i could slid the piston into the cylinder.



Now THAT's an idea!  I'm also a ham radio operator.  I have bags of zip ties to pick the perfect size for the job.


----------



## CFLBob (Feb 23, 2020)

Well, I'm not dead and I haven't given up on this.  Nothing I tried would get that piston into the cylinder, and after a self-imposed attempt to learn to measure better, I see why.  

I have three measurements at the bottom and top of the cylinder.  Their diameters are:  0.8831 top and 0.8819 bottom - that's .0011 bigger at the top than the bottom.   That's a little concern because I figure it's probably better if the bottom were bigger, not the top.   (Top is where the combustion chamber is)  As it is now, if the piston gets in the bottom as I assemble the engine, it will be looser - less compression - at the top.  

The piston, over the rings was 0.896 (!)  No wonder it couldn't get that into the 0.882 cylinder!  The piston itself is 0.878 other than over the rings.  

The drawings say the cylinder should be 0.875 and the piston 0.873.  There's no way to make the .883 cylinder smaller, but I could turn another piston, I just don't know what to do about the piston rings.  Then I got thinking that the piston over the rings was 0.896 and that's 13 mils bigger than the cylinder, so can I take up the 13 with rings instead of the 2 that it's originally specified at?  I'd make the grooves for the piston rings 13 mils deeper.  

One thing I knew is that the rings were too tight in their slots, so I tried to remove the rings and destroyed them.  You can see them here:






Since I'm starting over, I thought I'd ask what the rest of you think about which way to go?  New piston and new rings?  Modify (and finish) this piston?  Are polymer rings a good option here?


----------



## Brian Rupnow (Feb 23, 2020)

Bob--A Viton o-ring will work fine, but you will have to make a new piston to accommodate one. A ring of nominal 1/16" cross section x 0.875" outside diameter costs about a dollar. You only need one ring, and the groove should be 3/32" wide x .056" deep, about 5/16" down from the top of the piston. To make life simpler the piston can be .002" smaller in diameter than the cylinder bore. Run a 50:1 mix of two cycle oil in your fuel to keep the ring lubricated.


----------



## CFLBob (Feb 23, 2020)

Thanks, Brian.  Will a 0.875 piston ring be good for a cylinder that's 0.883 ID, .008" bigger?


----------



## minh-thanh (Feb 23, 2020)

CFLBob !
The way I do it:
While I cut the groove for the ring, I usually insert the ring into the groove to make sure the groove is deeper than the ring's height










*One more thing: I usually avoid talking about measurement results such as: 0.02 mm, 0.05 mm, 0.001 inch, 0.87 inch, or .., It is like hiding the measurement result, tolerance ... Because my measuring tools are cheap and inaccurate, sorry*


----------



## CFLBob (Feb 23, 2020)

Hi, Minh Thanh!

I like that idea of sliding the ring into the groove like you do.  

I understand what you mean about measurement tolerance of measuring tools.  Very important things to know.


----------



## Brian Rupnow (Feb 24, 2020)

Bob--try it and see. Viton o-rings sold as 1/16" cross section are actually 0.070". With a 0.056" deep ring groove, that gives .014" of "squish" radially. If you have .004" of radial clearance the viton ring should probably seal that with no trouble.


----------



## CFLBob (Feb 24, 2020)

I've been shopping at Grainger's - there's one a couple of miles from home - and they say they have rings with Nominal ID of 3/4", Nominal OD of 7/8" and actual OD of 0.879".  $6.38 for a bag of 50.  Since I've got an ID at the combustion chamber end of 0.883, it seems to be right on the edge.   

The next size up 13/16, 15/16, and 0.941, which seems too big every way.


----------



## minh-thanh (Feb 24, 2020)

CFLBob !
There are 2 ways: 1 Ringless . 2 Rings (buy it, make it, or O-rings) It only needs compression. Do it the way you want and be comfortable with it.


----------



## Brian Rupnow (Feb 24, 2020)

Do not buy normal buna N o-rings. they will melt. use Viton or go back to cast iron.


----------



## awake (Feb 24, 2020)

Bob, take what I am about to say with a BIG grain of salt, as I am still a complete novice on IC engines. But in my research on o-rings to use on my first build (in progress), it appeared that there was some wiggle room with respect to stretching the rings. IOW, if you size your piston appropriately, and size the grooves appropriately _for the cross-section of the ring_, then you can get away with stretching the ring a bit to fit in the groove.

I think. Did I mention salt?

But the key figure, as I understand it, is the cross section. Note how Brian has described it: nominal 1/16" rings with an actual cross section of .070"; grooves .056" deep by .094" wide; "squish" of approximately .014" (maybe actually .013" if your piston is .002" smaller than the cylinder). Even if you were to stretch the ring a bit (i.e., the diameter at the bottom of the groove is a bit larger than the actual ID of the rings), you won't change the cross section all that much; maybe you'll only get .012" of squish rather than .013" but it should still be enough.

I think. Anybody need salt?


----------



## awake (Feb 24, 2020)

To follow up a bit more - on my build-in-progress, also of a Webster (somewhat modified), I wound up using metric Viton o-rings (that was what was more readily available). They are described as 19 x 1.5mm, which means 19mm ID and 1.5mm cross section, for an OD of 22mm. It appears that the 1.5mm cross section is pretty much spot on, not a nominal figure. So, in inches, that is .748" ID, .059" cross section, and .866" OD.

My cylinder came out .8755". I sized my pistons as follows: .874 OD, with grooves .080" wide by .052" deep. This should give me a "squish" of around .006" (maybe too little, but read on). Note what the diameter at the bottom of the grooves is: .874 - .052 x 2 = .770" - somewhat larger than the .748" ID of the o-ring - so the o-ring is actually stretched a bit when seated in the groove. And that is important, because otherwise the OD would not be large enough - only .866 in a .8755 cylinder.

But if my understanding is correct - always a dangerous assumption! - then the ring stretches when seated in the groove, and the actual OD winds up at .770 + .059 x 2 = .888, maybe a little less due to the stretching reducing the cross section slightly. 

Does it work? Ultimately, that remains to be seen - I am getting close, close, close to attempting a first run, but not there yet. However, I have started to do some compression testing. First I assembled the flywheel, crank, rod, piston, ring, cylinder, and head. Even with the relatively small amount of squish and a generous helping of oil, it was quite stiff. I hooked it up to my mini-lathe and ran it for a few minutes, adding oil from time to time, and it got quite a lot smoother.

Then I added the spark plug. I pressed my finger over the hole that leads out to the valve cage, and tried to turn it over. Based on this highly scientific methodology, the compression seems to be excellent. Now I'm getting ready to add the  valve cage and valves, and we shall see how badly it leaks ...

Don't forget the salt!


----------



## CFLBob (Mar 29, 2020)

It has been another month, and while my progress moves as fast as a glacier, I'm still working on things.  

Let me start with the hardest part to measure, the cylinder.  In post 129, I said that I had found that the cylinder was tapered so that the combustion chamber end was wider than the entrance end, and if I could get the piston into the cylinder it would be looser in the most important zone. That told me it seemed like it would be better to open up the entrance to the cylinder (the bottom) so that it's at least as big as the combustion end. If I made the opening too big, that's better than the way it was.

I had measured it before and wanted to verify the measurements so I retook all the measurements and they were the same, which is a good thing.  I set up the lathe to carefully trim the inside diameter of the cylinder. I made a cut that should have taken .001" diameter off the first 3/4" of an inch of the bottom.  There was virtually no metal taken off - it looked more like dust than chips.  I thought I must have made a mistake setting up, so I reset the tool to the start of the cut and set it to take off another .001".  Again, no evidence of chips, just some fine scrapings of dust.  The micrometer and telescopic gauge were telling me that the diameter hadn't changed, saying that it wasn't cutting.  This went on a few more times until I had to think even I couldn't be that screwed up and the settings on the lathe couldn't possibly be right.  Still no evidence of cuts.  I stopped trying to cut, thinking I'd eventually mess it up if I kept going. 

After a few days of trying to figure out what was going wrong, I took a look at the carbide insert on my boring bar with a 10x magnifier and thought it seemed too rounded; perhaps the cutting edge was pushing the steel away from the tool at the contact point rather than shearing some off?  I rotated the insert to get a fresh point and started cutting without changing the lathe settings at all.  As soon as the tool touched the cylinder wall, I could see chips coming off, and before the tool had cut 1/8" into the length, I saw it was taking off too much.  Eventually I got a bell mouth by about .002 to .003.  

Last weekend, I had ordered replacement piston rings for the two I broke - and two spares.  They got here Wednesday.  After a couple of days of consistent measurements of the cylinder, I took it off the lathe and put the piston back.  Friday, I addressed the single biggest problem I had seen with the piston: the grooves were too tight and the ring wouldn't go to the bottom of the groove.  Using the same cutoff tool I used to cut the grooves, I got my positions reset and took off .002 of width on each ring's groove.  How much gap should there be on the sides?  I don't have any .001 or .002" shim material, or a feeler gauge that thin.






You can see a little light under the ring in each groove (the rings are called out at 3/32" wide but measure a little short of that: 0.090".  I haven't tried to install the rings, yet - I want to remeasure another dozen times since I don't know how to remove a ring if it's not right.   

The drawing for the piston (sheet 6) shows the bottom of the ring grooves as a reference dimension and if you take the reference (0.771) from the nominal dimension of the piston (0.873), that says the groove should be .051 deep.  My piston's OD is right around 0.878, not 0.873.  Should I try to keep the depth 0.051?  I'm using the piston rings from Dave Reed as called out in the drawings.  I think the rings were .044 thick.

I've spent a lot of my time making myself go to school on measuring ID with the telescopic gauges and just generally measuring better.


----------



## minh-thanh (Mar 30, 2020)

CFLBob !



CFLBob said:


> How much gap should there be on the sides?  I don't have any .001 or .002" shim material, or a feeler gauge that thin.











CFLBob said:


> The drawing for the piston (sheet 6) shows the bottom of the ring grooves as a reference dimension and if you take the reference (0.771) from the nominal dimension of the piston (0.873), that says the groove should be .051 deep.  My piston's OD is right around 0.878, not 0.873.  Should I try to keep the depth 0.051?  I'm using the piston rings from Dave Reed as called out in the drawings.  I think the rings were .044 thick



My opinion: it seems that the groove of the ring is not straight at the bottom, this will affect the height of the groove


----------



## awake (Mar 30, 2020)

Bob, I've not yet tried working with CI rings - I went the easy route and used a viton o-ring - so this is not from personal experience at all. But here is what Malcolm Stride says in _Miniature Internal Combustion Engines_:

"The ring should be a close but sliding fit in the groove, and the radial groove depth should be approximately 0.003in greater than the ring thickness."


----------



## CFLBob (Mar 30, 2020)

minh-thanh said:


> CFLBob !
> 
> 
> 
> ...



Minh Tanh - yes, the cutoff tool has a slight "U" shape to it.  It cuts deeper in the middle than the very corners.  I did a rough check of the angle a ring can lean and I see about 5 degrees, so it looks like I need to widen and deepen them a little.  



awake said:


> "The ring should be a close but sliding fit in the groove, and the radial groove depth should be approximately 0.003in greater than the ring thickness."



The ring is now above the piston by about that .003.  I will deepen those grooves.


----------



## minh-thanh (Mar 30, 2020)

CFLBob !
This may  be not necessary
Before you put the ring in the piston, put the ring in the cylinder and push the ring along the entire length of the cylinder (by the piston itself or some round bar you can push the ring  ) : this ensures that the ring and cylinder are fit
This may be not  necessary ... but I always do this before I put the ring into the piston


----------



## CFLBob (Mar 31, 2020)

I got the grooves much closer to what I wanted, then when I tried to clean out a corner by moving the cutter, it deflected.  I pulled it back out of the groove then overcut it.






These are two pieces of a broken ring from last month, not the new rings.  The rings are low enough in the slot that I can feel the edge of the groove by dragging a nail across the ring.  

Minh Thanh, I'm pretty sure I can do the test you describe, but I can't quite do it while the piston is in the lathe.  I think I'm ready to take it out of the lathe, cut off the handle and start machining the back side of the piston on the mill.


----------



## CFLBob (Apr 4, 2020)

Since Tuesday, I double checked the piston grooves, then took it out of the lathe chuck, turned it around and started work on the back.  I just hogged out a little material with drill bits .  

Since I don't have small Vee blocks, I thought I'd make a fixture for the piston to hold it tight in my vise without marring it.  I took a piece of scrap aluminum and made a hole in it that's about .003 bigger than the piston, then slit in half so that the two halves would be perpendicular to the vise jaws and clamp onto the piston.  I had the piston wrapped with a piece of soda can, also aluminum about .004 thick.  By itself, when I squeeze this, it doesn't want to close.  In the vise, it works as intended. 






Today I cut the features on the inside back of the piston and now the fixture's usefulness is done with for the time being.  

Now I need to mount the piston for the two cross holes, the .188 (reamed) hole for the wrist pin and the .094 hole for the oil tube.  Not sure how I'll hold those yet.


----------



## awake (Apr 4, 2020)

Nice fixture!


----------



## Brian Rupnow (Apr 5, 2020)

I have a rotary table with a chuck attached to it. For this operation on pistons, I set the chuck and rotary table so the rotating axis is vertical, and hold the piston in the chuck. I make certain that one jaw of the chuck is exacly on the right hand side, and put a spacer bar of 1/4" scrap aluminum between that jaw and the side of the piston. I use a dial indicator to center the piston under the quill, and machine the slotted hole in the Y axis. Then without breaking down the set-up, I unbolt the rotary table from the mill table, and tip it 90 degrees to the right, then bolt it down again and square it up to the mill table. Again, I use my edge finder to center the piston under the quill. Then I drill the wrist pin hole thru between the two chuck jaws which were originally on the left, thru the piston body and into the 1/4" plate of sacrificial aluminum, then ream the hole. This method insures that the wrist pin hole is perfectly square to the long slot in the piston.


----------



## CFLBob (Apr 5, 2020)

Brian Rupnow said:


> I have a rotary table with a chuck attached to it. For this operation on pistons, I set the chuck and rotary table so the rotating axis is vertical, and hold the piston in the chuck. I make certain that one jaw of the chuck is exacly on the right hand side, and put a spacer bar of 1/4" scrap aluminum between that jaw and the side of the piston. I use a dial indicator to center the piston under the quill, and machine the slotted hole in the Y axis. Then without breaking down the set-up, I unbolt the rotary table from the mill table, and tip it 90 degrees to the right, then bolt it down again and square it up to the mill table. Again, I use my edge finder to center the piston under the quill. Then I drill the wrist pin hole thru between the two chuck jaws which were originally on the left, thru the piston body and into the 1/4" plate of sacrificial aluminum, then ream the hole. This method insures that the wrist pin hole is perfectly square to the long slot in the piston.



The rotary table was my first thought, but the problem is I don't have a chuck on my RT.  I've just attached things to the RT with milling table clamps.  I keep thinking of making a plate to attach one but don't really see how to go about making one and haven't started.

I was thinking of putting something into the 3/8" pocket that has a way to ensure that's parallel to the chuck's ways, that are parallel to the table.


----------



## awake (Apr 5, 2020)

Bob, it is too late now, but I stumbled into a way that seemed to work pretty well - I drilled the wrist-pin hole _before_ milling out the slot. To do that, I held the piston crosswise in the vice, resting on parallels, with the top and the bottom of the piston contacting the vice jaws. I centered and located for the hole, center-drilled, drilled, and sort-of-reamed (that's another topic).

Then I could set the piston up in my v-block in the vise, _resting on a rod through the wrist pin hole_. This not only ensured that the piston was absolutely vertical, but also gave me a reference for the wrist pin; I adjusted until the rod was perfectly parallel with the vise jaws, and then I could mill the slot at a right angle using the y-axis.

None of which helps you now, since you have the slot but need the wrist pin hole. 

But here's my thought: make a jig that fits the slot and lets you set it horizontal, something like this:










The piston should just fit over the center stub. Put the piston on the jig into the vise so that the piston is aligned along the y-axis, resting on parallels; use a parallel or DTI or dead reckoning by eye to make sure the long part of the jig is perfectly parallel with the base of the vise (really, with the bed of the mill). Then center and locate and drill.

Yes, it would be something of a pain to make the jig as shown out of metal; you could make it easier by drilling two .25" holes .313" apart in the flat piece:





Then turn two pins, .375" diameter with a .25" stub on the bottom, and cut a flat about .040" deep on one face of each:






This lets the pins sit face-to-face in the base piece, forming the jig:






Of course, if you have access to a 3d printer, it would be relatively easy and quick to print up the jig as originally shown above.

I don't know if any of this will help - just my $0.02, off-the-top-of-my-head thoughts!


----------



## CFLBob (Apr 5, 2020)

What I was thinking of was like yours except instead of the long thin base, perhaps cutting it off of a 1/2" aluminum bar.  It would look like this






I think this could be made from a 1-1/2" long and 1/2 thick aluminum bar.  This would go into the piston's 3/8 slot, like yours, and this fixture would be held sideways in the jaws so that one of those large flat surfaces was the vise's bottom. 

I have some parallels that might be useful to keep it spaced well vertically in the jaws. 

No 3D printer - it's more machining time.


----------



## awake (Apr 5, 2020)

Hah - great minds think alike. Are you planning on holding the jig in the vise jaws, with the piston sticking out beyond? If so, how will you hold the piston in place - maybe Loctite?

That was part of my thinking with the jig that I show - it holds the piston between the jaws, but not in an orientation that could distort the round shape.


----------



## CFLBob (Apr 5, 2020)

No, I was planning on holding it in the vise jaws.  I just realized that 1/2 bar can't be 1" wide.  It has to be smaller than the piston's diameter so that the jaws would grab it.


----------



## awake (Apr 5, 2020)

Right, that was why I was thinking you were extending it out to the side.

But if your vise opens wide enough, consider turning it 90° and aligning the piston with the Y-axis. No chance of distorting the cylinder of the piston that way.


----------



## CFLBob (Apr 5, 2020)

Am I overcomplicating this?  I mean making a custom fixture to drill two holes?  

I just put the piston in the vise on a pair of spacers and eyeballed it in place.  I could use a 6" scale for a vertical reference, but that hole for the pin is twice the diameter of the setscrew holes.  I don't think I could get the angle far enough off to matter






Yes, it's in mid-air.  I had two parallels in there and took them out because I don't want to drill holes in them.  I'll put some scrap aluminum there to drill into.


----------



## Brian Rupnow (Apr 5, 2020)

Bob--If the bore for the wrist pin isn't exactly 90 degrees to the milled slot in the piston, the piston will rotate in the bore a small amount as it travels from top to bottom. Probably a bit of this "twist" is tolerable, but the closer it can be kept to 90 degrees, the better it will be.


----------



## werowance (Apr 6, 2020)

Bob,  how I did it was I have a 7/8 oversize er32 collet.  I put it in my rotary table to do both the slot in the bottom for the rod and then changed my table from vertical to horizontal and did the cross drill


----------



## werowance (Apr 6, 2020)

and I see that you don't have a chuck for it.  do you by chance have a collet chuck that fits your head stock?  my lathe headstock with chuck removed accepts an mt3 collet chuck.  which also fits my rotary table so I swap them around.  but I did have to buy an over size collet for it as 7/8 is larger than standard sizes in er32 I am told.  picked one up on ebay


----------



## CFLBob (Apr 6, 2020)

werowance said:


> and I see that you don't have a chuck for it.  do you by chance have a collet chuck that fits your head stock?  my lathe headstock with chuck removed accepts an mt3 collet chuck.  which also fits my rotary table so I swap them around.  but I did have to buy an over size collet for it as 7/8 is larger than standard sizes in er32 I am told.  picked one up on ebay



No, mine is pretty much factory stock with just an MT2 bore in the center, and I use a set of tee-nuts and clamps to hold things to it.  I bought an MT2 end mill holder to hold a gauge pin and use that to center the table under the quill, that's the only other thing I've bought for the RT.  I switched my big lathe over to a 5" chuck from the 4" it came with, and I could use the 4" chuck on the rotary table if I made a mounting plate.  

What I've been overlooking is that this is talking about my 6" rotary table on the big mill.  I have my Sherline "micro mill" with a 4" rotary table and I have both 3 and 4 jaw chucks for it.  I tend to think of using the Sherline for small parts and it's really great for that.  A 7/8 diameter piston would work on the Sherline.   I need to go look at that.


----------



## minh-thanh (Apr 6, 2020)

one more solution :


----------



## CFLBob (Apr 7, 2020)

I recreated your alignment, Minh Thanh, using a 1/4" gauge pin for the vertical edge.  







I drew a vertical line in paint.   Then I thought I'm not sure if the end of the gauge pin is really 90 degrees to the vertical - gauge pins are accurate for diameter, not squareness.  Because this piston isn't really big, none of my squares or 1-2-3 blocks or anything I have that I'm sure is square will fit in there and let me see the two holes.  It's probably "close enough".


----------



## minh-thanh (Apr 7, 2020)

......Measure the distance of 2 holes to the clamp ?!?


----------



## CFLBob (Apr 8, 2020)

minh-thanh said:


> ......Measure the distance of 2 holes to the clamp ?!?


That would be more work than what I did, and I don't think it would be much more accurate, if any.  I just don't have anything that I can fit in there.

So I set up this:





It's the same geometry but including my center drill to spot the hole.  

After all the agonizing over the accuracy of setting up the drilling, drilling went quickly. 











I never cease to be amazed at how dirty things are that I've just spent time cleaning when I look at them under this sort of magnification.  I also see some places to de-burr better.  The only thing not in this picture is the 3/32 OD, 1/16 ID brass tube.  I think I'll make that from a scrap piece of 1/4" brass rod I have.

Now I think it's on to the connecting rod and keep going.  There are a few bearings on page 7 that use bearing bronze and I don't have any.  It's a good time to see if there's any materials I need to get.


----------



## CFLBob (Apr 10, 2020)

While my lifetime supply of 3/8" "bearing bronze" is on the way, I have a few parts to knock out.  The fiddly bits are perfect for my Sherline manual lathe.  The oil tube through the piston is 3/32 with a 1/16" hole down its axis.  I thought I only had 1/4" brass rod, but found a few inches of 1/8" rod in an out of the way pile, so it was easy to whip out a couple.  

Only I made the first one 5/16 instead of 3/16.  This almost takes longer to describe than do. 






I found some 5/16" plate for the conn rod so I think I can start on that tomorrow.  I have the drill rod for the wrist pin and that should only take a little longer than this did.


----------



## awake (Apr 10, 2020)

Nicely done!


----------



## werowance (Apr 13, 2020)

I cheated on my oil tube on the side of the piston. i used brass tube and swelled it with an awl that fit in which gave a taper to it.  pressed it in and filled off the excess.  I kept breaking the part when I tried to turn it because it was so small and thin walled


----------



## CFLBob (Apr 13, 2020)

werowance said:


> I cheated on my oil tube on the side of the piston. i used brass tube and swelled it with an awl that fit in which gave a taper to it.  pressed it in and filled off the excess.  I kept breaking the part when I tried to turn it because it was so small and thin walled



I tried to insert the one that's the right length and it wouldn't go, just holding both parts by hand.  The first one fit.  I measured the OD again and it said .097, but when it was on the lathe I was pretty sure that it measured OK.   So I figured I'll do a third, but I should try your method first.


----------



## awake (Apr 13, 2020)

I also cheated on mine ... and didn't put the tube in. I also didn't put the oiler on the cylinder, because I wound up with the wall just too thin to be able to thread the oiler in. So I just occasionally line things up so the hole in the cylinder aligns with the hole in the piston, and dribble in some oil. So far, so good ... but I've only got maybe 1 hour of total run time, maybe a bit more. Mind you, in terms of # of runs, I'm up to at least 60 - but I rarely run it for more than a minute or two at a time.


----------



## CFLBob (Apr 13, 2020)

I think that's reality, Andy.  I can't imagine running it for hours to do anything.  It will probably run a few minutes at a time, and then sit on the shelf on a pretty plaque.  

I seem to recall someone said they used a two-stroke style premix of some oil mixed in with the fuel.  I have a boat with a two-stroke outboard so I have a gallon of that 50:1 oil in the garage.


----------



## awake (Apr 13, 2020)

I've seen a number of folks talk about using an oil-mix to avoid dealing with lubrication. I can see how this would keep the piston lubricated, and the valves ... not so sure how it would lubricate the small end of the rod up inside the piston.

I am running my Webster on straight Coleman fuel, just adding occasional oil to the cylinder as indicated above (and at the same time oiling the gears and rocker arm pivot - and sometimes trying to get just a bit of oil on the valve stems) - everything I've read suggests that using automotive gasoline is not so great. I've also read that some use the Coleman fuel mixed with some WD-40 to provide lubrication.


----------



## werowance (Apr 14, 2020)

actually the Webster  gets so hot I don't think  it would actually run for more than 15 to 20 mins at a time anyway between cool downs.  pretty sure I couldn't get an hour continuous out of mine.


----------



## Brian Rupnow (Apr 14, 2020)

I run my Webster on Coleman fuel (naptha gas) with a small percentage of 2 cycle oil.  If you want it to run all day, rig up a small fan to blow over the cylinder, driven by an o-ring drive belt. It will run all day.


----------



## awake (Apr 14, 2020)

Clearly I am not adventurous enough, not having run mine for more than a couple of minutes at a time! Partly that reflects the fact that I don't know how hot is too hot - at what point I need to start worrying about seizing up the engine or doing other damage.

I had considered rigging up a fan, and might still do so - there is a spot I might could squeeze it in. But I'm already thinking about engine number 2, which - if it actually works - will be my own design, and it does include a fan.


----------



## CFLBob (Apr 14, 2020)

Thanks, Brian.  

My bearing bronze is supposed to be here Friday, so looking over the prints, do I recall you using a pre-fab carburetor and not Websters's original? Since in his own notes he says, "Do yourself a favor and skip building this VENTURI and NEEDLE VALVE ASSY", I guess it's getting to be time to look for a carburetor.  

Florida is kind of the opposite of the rest of North America.  You're getting ready to get out of your garages and get to real life outside (I guess this year it's as much as you location allows).  I'm getting ready to stop going outside and stay in the shop more, except for my every other day bike ride, and stuff like grocery shopping.


----------



## awake (Apr 14, 2020)

Bob, I hesitate to offer an opinion, since I only have the one build under my belt - but for what it is worth, I decided to go with Chuck Fellows' carburetor for my Webster build, and I've been very happy with it. I have no basis for comparison, so I don't know what might work better - but honestly, it is hard for me to imagine anything working much better. Compared to other carburetor plans, I would say Chuck's is commensurate with the beginner level of the Webster. The hardest part is drilling the teeny-tiny hole for the jet ... I will confess to making that part 3 times.


----------



## stevehuckss396 (Apr 14, 2020)

Automotive "pump" gas isnt good because it contains alcohol. I run automotive racing fuel. It smells awesome when you burn it and it's half the cost of coleman fuel and no alcohol. I mix some WD-40 with the gas because I run steel liners with cast iron rings and the WD-40 keeps the ring from sticking to the cylinder wall when sitting on the shelf between shows.


----------



## CFLBob (Apr 14, 2020)

awake said:


> Bob, I hesitate to offer an opinion, since I only have the one build under my belt - but for what it is worth, I decided to go with Chuck Fellows' carburetor for my Webster build, and I've been very happy with it. I have no basis for comparison, so I don't know what might work better - but honestly, it is hard for me to imagine anything working much better. Compared to other carburetor plans, I would say Chuck's is commensurate with the beginner level of the Webster. The hardest part is drilling the teeny-tiny hole for the jet ... I will confess to making that part 3 times.



I downloaded the plans for Chuck Fellows' carburetors from the download section; I saw two different carbs, with the major difference being the drawing called 371 had a flange on one end.   I'll have to think about that.  Compare and contrast to an RC Glow Engine as Webster talks about.


----------



## aka9950202 (Apr 15, 2020)

I used a Jan Ridders vapour tank/carburetor on my engine. The fuel was from the 2 stroke weed wacker which is 50:1. The only speed control is to change the mixture. 

Cheers, 

Andrew in Melbourne


----------



## awake (Apr 15, 2020)

Bob, I found 3 different versions of Chuck's carb floating around on the web - all of them by Chuck himself, as best I could tell - but none of them included a flange! Obviously there are multiple versions out there ...

... including mine - the major difference between the versions that I found was the bore diameter - either .125" or .156 - and the size of the screws that form the jet and the throttle.

I split the difference on the bore, going with .140, and used 8-32 as the thread for the needle/jet and 10-32 as the throttle:





Notes:  1) The plan abve shows 10-24 for the throttle - I thought I would want the faster motion of a coarser thread - but when it came down to it I decided to use 10-32 instead, and as noted in a post above, I've felt like it has all the response I need or want. It seems pretty sensitive to both needle and throttle settings - very little motion gives large results. 2) Not shown in the plans are two springs, one on the needle and one on the throttle, intended to keep these from moving under vibration. The springs do seem to fulfill that intent, but they also lead to the need to allow for a tiny bit of "spring back" when making an adjustment.


----------



## CFLBob (Apr 23, 2020)

Putting the carburetor aside "for now" I'm getting set for the connecting rod.  I cut a blank that's a little tapered for this but has enough spare material on all sides to fit.






The left side of the vise's back jaw is X=0 and the front of the back jaw is Y=0.   When I put a piece in the vise, it's easy to use my CNC as just DROs to go to the point where the two holes get drilled.

My plan is to drill a hole in the center of each bearing but not the final size, just big enough to clear a 10-32 screw.  Then I'll use the two screws to mount this onto my shop made tooling plate. Then I'll cut the outlines under CNC.  

Or I could just make it simpler like the conn rod in my Duclos flame eater.  This is prettier than it has to be, but I think most of us like the challenges of making stuff like this.


----------



## awake (Apr 23, 2020)

CFLBob said:


> My plan is to drill a hole in the center of each bearing but not the final size, just big enough to clear a 10-32 screw.  Then I'll use the two screws to mount this onto my shop made tooling plate. Then I'll cut the outlines under CNC.



That's pretty much what I did, except that 1) no CNC, so I used the rotary table, and 2) I went ahead and made the holes full-sized, and made pins to suit for the tooling plate. Your approach will be quicker and easier!


----------



## Brian Rupnow (Apr 23, 2020)

A Traxxas 4033 carburetor will run this engine just fine. So will chuck's carburetor.


----------



## CFLBob (Apr 23, 2020)

Thanks, Brian.  

That Traxxas carb seems like a good trade off of a little cost vs time.


----------



## CFLBob (Apr 28, 2020)

I have the rod roughed out and ran into a problem with cutting the final pass, which takes off the 1/32" in the middle of the rod and leaves the circular outline around the bearings.  I'll do that same cut on both sides of the rod.

I'm using an old version of DeskProto for my CAM program and it just refuses to do things the way I think they should be done.  I see this as cutting an arc on each end of the rod, but I could do two circles instead of arcs and cut a lot of air.  It's an easy piece of Gcode with the G02 or G03 commands.  So I wrote a file to do it that way.  Go to the right side of the first circle I'm going to cut, cut it, the move to the left side of the bigger circle and cut that one.  As the cutter moves from the first to the second circle, it thins the whole rod by that 1/32.  I proofed the cut in GWizard and it comes out just like it should.







The green is the path of the center of the cutter (1/2" End mill).  The red arrows I drew in to show how it's supposed to cut.  

I take the file out to the mill, and Mach3 shows an entirely different picture.  The circle on the right is so big it includes the circle on the left.  I did a test air cut and that's what it did.  It's like Mach3 and the GWizard editor are speaking entirely different languages.  But only on circles because I often use it to proof cuts and this is the first time they've disagreed.

It looks like I have to spend some time with Mach3 and figure out why it's cutting differently.  I know I've done circles before and they came out fine.  I made the pieces for my Grizzly CNC conversion on my Sherline and cut out a few circles on the motor mounts, all coded by hand this way.


----------



## CFLBob (Apr 29, 2020)

You can see what the tool path was supposed to look like above.  This is what Mach3 thought it was supposed to look like.  The little circle is approximately right but the big circle is way too big and cut in the wrong direction.






It turns out that Mach3 had been set to always be in absolute coordinates.  In general, I like that way of working, but it was killing me here.  Deep in the manual, page 10-30, it says that this can be overridden for G02 and G03 cuts, which is what I was doing.  Once I figured out that's why it was acting like the big circle wasn't listening to my commands, it took very little time to finish it.  Cut the circle on one side , which also cut the relief between the circles.  Flip it upside down and do the other side.






I notice I didn't center the small end in X, only Y, while I did both for the big end.  Ah well... 

Back when I took my first programming class there were no home PCs and we had to go to terminal rooms on campus to work on our programs.  Every computer room I ever walked into had this limerick somewhere on the walls:

I really hate this damned machine
I wish that they would sell it.
It never does do what I want
Only what I tell it. 

It was doing what I was telling it to do.


----------



## awake (Apr 30, 2020)

Yep, as a former software developer, I can relate to that little poem!


----------



## CFLBob (May 9, 2020)

This week, I cut the bearings that go into the ends of the connecting rods.  Unfortunately, I hadn't noticed that I didn't have the 0.281 (9/32) reamer needed for the big bearing so I had to go order one of those and leave the bronze in the lathe chuck while I waited a few days.  I haven't LocTited the bearings in place yet, but that won't take long.  

Back when I was working on the crankshaft, I decided to adapt an idea from someone (I think it was Brian, but I'm not sure) for an end with better balance.  I cut that yesterday.  First the Ta Da! shot, still on the tooling plate and not Done done.  





The original has a 1/2" diameter raised area where that big washer is.  I'm leaning toward not doing a second pass to make that and I'll just use it like this.  Why?  I think that raised area is for making this out of brass or bronze and silver soldering it to the crankshaft.  Since this is aluminum I'll just use red Loctite instead of brazing it on. 

On to the real reason I'm here.  Does anybody else use a Fogbuster?  Mine quit working as I was starting to cut this.  I kept going because the air flow was fine and I heard that the air flow cooling the cutter and blowing away chips was often enough.  It worked in the sense of keeping the cutter from having chips weld onto it, but the cut was pretty barf-y looking (technical term).  It almost looked like the aluminum melted and refroze because the sides were shiny and ripply.  I cleaned up the part's edges with a fine file. 

It had plenty of pressure and the air is just fine, it just never sprayed liquid.  My gut feeling is it probably has some dried out gunk in it and I need to do something to clean it out.  I tried to pull the hoses off it yesterday and couldn't.  I almost cut them off and then said I'd go look on their website for some hints.  I find no maintenance or troubleshooting help there.

So what should I do?  Cut the hoses off and soak it?  Ram a pile cleaner or wire or something up the nozzle?  Any ideas or suggestions would be appreciated.


----------



## L98fiero (May 10, 2020)

CFLBob said:


> On to the real reason I'm here.  Does anybody else use a Fogbuster?  Mine quit working as I was starting to cut this.


Just a suggestion, while it's blowing air, put your finger over the end, that will create back pressure in the fluid line and clear chips/dust from the needle valve.


----------



## CFLBob (May 10, 2020)

L98fiero said:


> Just a suggestion, while it's blowing air, put your finger over the end, that will create back pressure in the fluid line and clear chips/dust from the needle valve.



I put the wire up the nozzle and never felt anything.  I also increased the pressure from the normal 15 psi up to 30 and that never blew anything out.  So I cut off the hoses and put some vinegar into the input that gets the coolant, let that soak for 5 minutes.  I can shine a flashlight into it and it looks clean - I don't see anything in it.  Nothing helps.


----------



## CFLBob (May 10, 2020)

Aside from the problems with the fogbuster, I finished the bearings and the rest of sheet 7.  






Those bronze bearings are held in with red LocTite.  

It's on to sheet 8 although I've got to get my Fogbuster working again.


----------



## CFLBob (May 11, 2020)

And here's the counterweight, with 1/4 and 5/16" pins.






It needs more finishing to be prettied up.


----------



## werowance (May 11, 2020)

looking good Bob.


----------



## CFLBob (May 26, 2020)

OK, I made a screwup.  See the dimension in red?  I have some 1/4" stock that I thinned out to 3/16 - .188 instead of .219.






Put in the scrap pile and start over?  Or does it matter?  

Didn't realize it has been two weeks since I posted something.  Had a temp job I had to put some time into.  And then fell through.


----------



## Brian Rupnow (May 26, 2020)

3/16" will work okay.


----------



## awake (May 26, 2020)

Brian beat me to it - in my opinion it will be fine; just might have to adjust the pin on which it rides and the location for the tappet that acts against the valve.


----------



## CFLBob (May 26, 2020)

Thanks.  I got started on the replacement anyway, but it's just cut a bit oversized and squared.  And it's .219 thick.  

My problem was not understanding exactly how it goes together.


----------



## stevehuckss396 (May 26, 2020)

Myself I would start over. With a 0.125 hole cross drilled in the part it will get awful thin in that area. The thicker the better. That's just me.


----------



## coulsea (May 26, 2020)

I would have used the 1/4 the way it was.


----------



## CFLBob (Jun 4, 2020)

This part took longer than it should have because of my "comedy of errors" (where the important word is errors, not comedy).  I wasted a couple of pieces of steel before I smacked myself upside the head about not paying enough attention!  I put a 4-40 Socket Head Cap Screw in the tapped 4-40 hole on the right just because.  Although that does make it look a little wonky.


----------



## awake (Jun 4, 2020)

But now it's done! What's next?


----------



## CFLBob (Jun 4, 2020)

The rest of sheet 8.  I'm just going through the sheets and knocking off parts.  Most of sheet 8 looks pretty easy except for the cam.  I've never done one of those.

I was just looking at the rocker arm spring.  It says .010 thick spring steel and 0.281 wide.  I have no idea what that is or where to get some in reasonable quantities and prices.  My only experience making springs was with music wire.  See I can get 50 inches from Online metals for $78.  Since I need less than 3 inches, I was thinking of buying 6.


----------



## awake (Jun 4, 2020)

Bob, when I made my somewhat modified Webster, I had planned to use a standard compression spring. I drilled the rocker arm to thread a bolt through, about half-way between the rocker arm pivot point and the area that contacts the cam. I was going to put a matching bolt in the stand below, so that together they would keep a spring aligned to act on the rocker arm. But I noticed that my rocker arm came out heavy on the valve end, due to the extra material on that end and the screw that acts as the tappet. As a result, it naturally "falls down" on that end, keeping the other end in contact with the cam. I decided to try it without a spring ... and it seems to work just fine, so I've never bothered putting in a spring.

Since you are making the Webster much closer to the original plans, it may be that the spring is really needed ... but even if it is, I would think you could use a standard spring the way I had planned to do.


----------



## CFLBob (Jun 4, 2020)

Thanks, Andy.  It never hurts to make it like the prints, so that's the way I'm going.


----------



## awake (Jun 4, 2020)

CFLBob said:


> Thanks, Andy.  It never hurts to make it like the prints, so that's the way I'm going.



Indeed, and that is something I'm enjoying about your build - making other choices (on my first build!) has left me with questions on what I might have missed. I'm finding out, vicariously, through your build!


----------



## CFLBob (Jun 4, 2020)

Well, I don't understand enough about engines to change it as I go, so there's that.  

Not knowing what you're doing tends to make any little difference scarier than it should be.


----------



## Longboy (Jun 4, 2020)

CFLBob said:


> I was just looking at the rocker arm spring.  It says .010 thick spring steel and 0.281 wide.  I have no idea what that is or where to get some in reasonable quantities and prices.........


If you take out one of the thinner strips out of a feeler gauge set and cut/ trim Bob, you will have a proper spring for Webster!    .....   Dave


----------



## ZebDog (Jun 5, 2020)

Hi Bob
 When built my Webster I drilled a 3mm hole in the bottom of the rocker arm and loctite in a small peg and used a compression spring from an old pen


----------



## stevehuckss396 (Jun 5, 2020)

You can get 100 foot in 1 foot pieces of steel .010 wire at McMaster Carr for 10 bucks.


----------



## werowance (Jun 5, 2020)

CFLBob said:


> This part took longer than it should have because of my "comedy of errors" (where the important word is errors, not comedy).  I wasted a couple of pieces of steel before I smacked myself upside the head about not paying enough attention!  I put a 4-40 Socket Head Cap Screw in the tapped 4-40 hole on the right just because.  Although that does make it look a little wonky.
> 
> View attachment 116853




Bob, i think I had to re-make that part 3 times before I got it right.  I kept moving in the wrong direction thus cutting it to thin.  something about that drawing just would not "click" in my head so I kept doing it wrong.  but yours look good.


----------



## werowance (Jun 5, 2020)

also on the spring for the rocker arm,  I used a broken band saw blade,  use the grinder and the belt sander to make it to size.  it was still a little thicker than plans but works well and holds its springiness (technical term) well.  Brian R used a recoil spring from an old push mower blower housing or some small engine blower housing I should say.  I had a Honda recoil spring and it was a bit narrower than plans so I opted for the broken bandsaw blade I had.


----------



## Brian Rupnow (Jun 5, 2020)

Go to a small engine repair shop and ask them for the broken recoil/rewind spring from a lawn mower, chainsaw, or weed-eater. That works perfect for this application.


----------



## CFLBob (Jun 5, 2020)

Thanks for all the suggestions, guys! 

All of those give me ideas.  I use my feeler gauges at the mill every time I set it up, so I'll probably keep that intact, but a pen spring or coil spring sound really easy.  The one kind of spring I've made is a wound coil with music wire and I still have lots around.  I probably a half dozen springs lying around I tried for some repair or something.  And I'm about to replace the blade on my wood-cutting bandsaw, so I'll have plenty of possible blanks from that.

Werowance, I was half expecting someone to say, "that's exactly like the (some name) spring out of a Honda you can get at the auto parts store."


----------



## minh-thanh (Jun 5, 2020)

Hi Bob !
Just curious, how many parts of this engine did you make?
And what's the rest ?


----------



## CFLBob (Jun 5, 2020)

Hi Minh-Tanh,

The parts start on sheet 2 of the plans I downloaded here, and I've made everything from sheet 2 to sheet 7.  I think this arm was part #17, the first part on sheet 8.

There are parts I'm not sure I'm going to make, like the oil cups that feed into various points.  I hear both ways on that.  I'm probably going to buy a Traxxas carburetor and there are a few things I'm not sure of.


----------



## a41capt (Jun 5, 2020)

The rocker arm was one of the last parts I completed before my workshop turned into a 108 degree oven.  I used Kasenit on the rear cam bearing surface and then Followed with a black oxide finish using my favorite cold gun blue made by Van’s. I heat the parts to be blued with a heat gun and submerge them, followed by an immediate oiling and they turn out uniformly black. This is about the only “cold” bluing solution I’ve used that doesn’t streak.


----------



## CFLBob (Jun 19, 2020)

Does anyone have an Upshur cam fixture handy that can check a dimension for me? 

I don't have the plans for one, but I found a video on YouTube where a guy makes shows one and how he works the cam.  He doesn't say anything about how he made it or what the dimensions are, but at the end he shows the diagram he worked from.  I took this screen shot from his video and I'm making the fixture from this:  






My question is in the upper right drawing (and everywhere), the center of the rod that holds the cam blank looks closer to the edge than the center.  The drawing says it should 3/16 offset from the center.  I'm set to drill this hole on my mill but it looks closer to the center than the edge.  

That makes sense because if the center is at 1/2", 3/16 less than that is 5/16 or 0.313.  But the drawing makes it look like it's 3/16 from the edge and not from the center.  Come to think of it, the center being 3/16 from the center would put the closest side of a 3/8 bar right on the center.  

Can anyone measure theirs, or has made one and just knows what it is?  


Thanks!
Bob


----------



## Ghosty (Jun 19, 2020)

It may just be drawn like that for clarity, rather than being correct. Offset listed at 3/16", and dia of block 1" (but can be larger), 1" looks like the min size that the designer decided that has the best grip in the chuck.
Cheers
Andrew


----------



## CFLBob (Jun 19, 2020)

I don't know.  

I've made 3D models of this stuff and the numbers don't seem to work out.   The bottom half of the cam (the base circle?) is supposed to have a diameter of 9/16, so a radius of 9/32 or 0.2812".  If I put my model cam blank on the end of the 3/8 shaft,  the smallest I can cut that is 0.312 or 5/16.  That means I cut past the edge of the 1" cylinder, but I guess nothing is stopping that.  

It seems that the fixture just does a better job of holding the blank than a person could hand hold it, but it's pretty much just shaping the cam by hand on the fixture.


----------



## Cogsy (Jun 19, 2020)

CFLBob said:


> I don't know.
> 
> I've made 3D models of this stuff and the numbers don't seem to work out.   The bottom half of the cam (the base circle?) is supposed to have a diameter of 9/16, so a radius of 9/32 or 0.2812".  If I put my model cam blank on the end of the 3/8 shaft,  the smallest I can cut that is 0.312 or 5/16.  That means I cut past the edge of the 1" cylinder, but I guess nothing is stopping that.
> 
> It seems that the fixture just does a better job of holding the blank than a person could hand hold it, but it's pretty much just shaping the cam by hand on the fixture.



The offset from the centreline is just going to give your flank radius isn't it? You can have the fixture as large as you want and it shouldn't make any difference to the size you can cut the base circle to, but the further offset you have the 'gentler' the flank curve. I don't see why you couldn't machine the base circle all the way down to 3/8" (except the part would obviously be machined away to nothing).


----------



## a41capt (Jun 20, 2020)

Bob,

the dimensions you’re referencing are correct, the drawing just looks not to scale.  Here’s a couple pics for you of my setup:


----------



## a41capt (Jun 20, 2020)

one with all the accoutrements


----------



## a41capt (Jun 20, 2020)

And one mounted up in the lathe with the cam in place. This one is staged with the cam already case hardened:


----------



## CFLBob (Jun 20, 2020)

a41capt said:


> Bob,
> 
> the dimensions you’re referencing are correct, the drawing just looks not to scale.  Here’s a couple pics for you of my setup:View attachment 117269



Thanks!  Very helpful.  I was just about to head out to the shop and MIL-TFP figuring if it didn't work, I could just redo the hole on the other side of the center, or on any radius.    

(MIL-TFP - an old joke from a made-up MILSPEC.  "Make It Like The F*ing Plans"  Usually followed with -41C "for once")


----------



## CFLBob (Jun 20, 2020)

Onward to actually cutting this thing.  Before that, I'm going to make some landmarks on the blank to cut to.


----------



## CFLBob (Jun 21, 2020)

The process was pretty much as I expected; very manual.  I think it's like holding the cam against a grinding wheel, except I think that would turn out smoother and better looking.  After spending 3 or 4 hours, I have something that has a cam-like shape, but any outside dimensions that match are purely a coincidence.  I'm assuming that this isn't usable.  






I know an experienced machinist that I swap emails with now and then, and I told him what I was doing.  He asked that since I have a CNC mill, why would I even try to do this?  Just clamp it to the table and cut the outline.  I did that with the crankshaft counter weight in post 191.

CNC is the strong point in my shop.  I need to get better at turning drawings into tool paths.  

I will probably try to make one with CNC later today.


----------



## Cogsy (Jun 21, 2020)

How did you go about the cutting? I ask because it looks like there are several different 'lumps' on the cam. 

I would have thought the procedure would have gone something like: clamp the blank in the holder and take multiple passes until down to the base circle radius at that one point, then lock the cross-slide at that depth for the rest of the job. Now stop the lathe and rotate the blank by a small amount (probably around 5 degrees) then take a single pass. Now keep indexing around the 5 degrees and taking single passes until you measured nose width is all that is left uncut. This should leave a decent cam with very small facets which should file smooth in a minute or two with a small file (especially under power if you're happy to do it).

Having said all that, for a cam like that I'd use a boring head in reverse on the mill and index it with a rotary table but I think this fixture was likely developed for builders who didn't have access to a mill at all.


----------



## CFLBob (Jun 22, 2020)

Cogsy said:


> How did you go about the cutting? I ask because it looks like there are several different 'lumps' on the cam.
> 
> I would have thought the procedure would have gone something like: clamp the blank in the holder and take multiple passes until down to the base circle radius at that one point, then lock the cross-slide at that depth for the rest of the job. Now stop the lathe and rotate the blank by a small amount (probably around 5 degrees) then take a single pass. Now keep indexing around the 5 degrees and taking single passes until you measured nose width is all that is left uncut. This should leave a decent cam with very small facets which should file smooth in a minute or two with a small file (especially under power if you're happy to do it).
> 
> Having said all that, for a cam like that I'd use a boring head in reverse on the mill and index it with a rotary table but I think this fixture was likely developed for builders who didn't have access to a mill at all.



Hi, Al,

That's what little I got out of the video.  I turned the blank more than 5 degree increments, though.  Never thought about it, but more like 30 degrees.  It never looked like the diagrams in that little screen capture I posted.   One problem is that once you've set the cut, I think you've cut the bottom of part.  The diagrams show going in one direction, but I thought you had to reverse.  The instructions in that video really didn't help me.

The way I look at this is that it was interesting to see how the lathe can be used, but I really didn't know how to use it properly.  Each blank takes about 0.3 inches and I started with a foot long bar of 12L14 steel.  Right around 40 blanks.  I can keep going until I get it right or I can change it over to the mill and shape it under CNC.  I have another blank ready to cut.


----------



## stevehuckss396 (Jun 22, 2020)

Take a look at this article. It shows how to form a lobe using the exact method you tried. It works for one lobe or a v8 full of them. All you need to do is figure out how to index the lobe on the fixture a little better and you would have had you a nice part. You already have your fixture made so it's worth another go.


----------



## werowance (Jun 22, 2020)

bob, the webster doesnt have to have sloped flanks,  they can be flat.  in my build i have a drawing that shows the cam,  you can do it with flat sides so all you need is a rotary table only.


----------



## werowance (Jun 22, 2020)

heres the link to the post if it helps





						Werowance builds a webster
					

I don't know if this helps or... But I have a few times  do the same method Lathe speed is slow and several times replace sandpaper




					www.homemodelenginemachinist.com


----------



## CFLBob (Jun 22, 2020)

stevehuckss396 said:


> Take a look at this article. It shows how to form a lobe using the exact method you tried. It works for one lobe or a v8 full of them. All you need to do is figure out how to index the lobe on the fixture a little better and you would have had you a nice part. You already have your fixture made so it's worth another go.



Thanks, Steve.  That really helps.  Neat fixture, too, for doing an entire shaft.   

47 step of 5 degrees?  Sounds like a piece of cake.   I know I didn't step anywhere near as fine as that.  Probably about 30 degrees because that's like 7 or 8 steps which is more like what I did.  I need to draw up a 5 degree angle to put somewhere handy so I can see visualize it on the metal easier.


----------



## CFLBob (Jun 22, 2020)

werowance said:


> heres the link to the post if it helps
> 
> 
> 
> ...



Yes, it does help.  Thanks for that.  The part about knowing when to move the rotary table straight was bothering me about Chuck Fellows' method, when I watched his videos.  I couldn't figure that out.  

I'm leaning toward getting the Upshur method on the lathe to work and if that doesn't work, try CNC on the mill.  Since I have it sitting there.


----------



## Brian Rupnow (Jun 22, 2020)

Using the Chuck Fellows method does not require that the rotary table must be moved anywhere. It only rotates. It is hard to get your head around, but it works extremely well and once you have cut a cam using that method , you would never go back to trying to do it on a lathe.
 As a general rule of thumb, if there is a cam follower wheel contacting the cam, then the cam can have flat (straight line) flanks. If a tappet rides on the cam, then it needs curved flanks.--Otherwise, if you use a cam with flat flanks it will come around and slap the flat bottom of the tappet, causing the valve to bounce.


----------



## CFLBob (Jun 22, 2020)

I've only watched one video by Chuck and only once, so I probably got it wrong.  I was pretty sure I saw him moving the mill's table, with the RT on it and thought I recalled him talking about it.


----------



## Brian Rupnow (Jun 22, 2020)

Here is a post I made about using the Chuck Fellows cam making video.





						Quick way to cut a cam
					

I first seen this method of cutting a cam on a YouTube clip posted by Chuck Fellows. In his video, he attributes this method to Randall Cox. I have made cams using various methods, and this is by far the fastest method if you want a cam with a "flank radius" between the base circle and the nose...




					www.homemodelenginemachinist.com


----------



## CFLBob (Jun 22, 2020)

This is the video I watched over the weekend

The only motion of the mill table was setting the depth of cut, as with the video you linked to.  I screwed up the first time and didn't grasp it.  No idea how, but that's not as important as getting it right now.


----------



## CFLBob (Jun 23, 2020)

Well, thanks to Steve, @stevehuckss396, the second attempt at turning on the Upshur fixture looks better than the first and is better in every way except one.  






The entire bottom half (actually 212 degrees of arc) is supposed to be .094 wide but it's wide by a full 1/32 - .124.  My fixture has a half inch diameter washer over the 3/8" hole (filled with a 3/8 rod in the fixture - so it can't move that much.  I measured the same way as on the first one.  I measure the difference between the blank as I'm turning it down and that half inch washer.  It should measure .031 and I thought it did.  I didn't see a way to fix this but it might have just occurred to me.  

What if I put it back in the fixture with the middle bottom at the closest, cutting point, trim that back until it's the proper thickness, then do my 5 degree counterclockwise turns every 5 degrees until I get to the edge, then turn the blank over on the fixture and go back to the starting point?  It approaches the top of the cam from the same direction (CCW) on both sides.  I don't see how I could go from one side of the cam all the way around with one fixturing.


----------



## Cogsy (Jun 23, 2020)

I can't see why your plan wouldn't work. I also can't see why you couldn't start in the middle like you plan to, cut in one direction (CCW it seems) then reset to the middle and cut in a clockwise direction to finish that side. The fixture should allow you to cut in both directions I think.


----------



## stevehuckss396 (Jun 24, 2020)

Keep in mind that the depth of cut is the lift. Just touch off on the blank and cut what ever the lift is deep. Then rotate and repeat.


----------



## CFLBob (Jun 25, 2020)

I think I have a cam.  Well, I'm all but positive I have a cam.  Quick summary: 






Left to right, first try, then second and third try (on one blank) and today's fourth try.  

The first and second are described in the last few posts.  The difference between 2 and 3 is that I re-mounted the cam on the fixture and set the depth of cut to get the required wall thickness at the bottom.  The problem is the top of the cam.  It's easy to see it's too narrow.   Instead of 0.254, it's closer to .200.   

I think that on one pass midway up the left side, I guess I didn't tighten the SHCS tight enough and the cam slipped getting over cut.  

The fourth try was done on my CNC mill.  I wrote the G-code by hand.  I had fixture with a hole just about perfectly sized for a 1/4-20 screw, so I turned a bushing that press fit into the 3/8 hole and would pass a 1/4-20 screw.  

Onward.


----------



## Tim1974 (Jun 26, 2020)

Keep at it bob looking good I’m enjoying the build


----------



## stevehuckss396 (Jun 26, 2020)

You're not done yet. You still need to shape the nose to eliminate the sharp corners. Most commonly done with a file.


----------



## CFLBob (Jun 26, 2020)

stevehuckss396 said:


> You're not done yet. You still need to shape the nose to eliminate the sharp corners. Most commonly done with a file.



For sure.  There's a bit of a bur along all the edges, too.  That's almost right off the fixture.  I just barely cleaned it up.


----------



## CFLBob (Jun 30, 2020)

I'm getting to choices that affect the parts I build.  One of those is electronic ignition.  I know I've seen some use of those on a Webster instead of points and capacitor but can't seem to find a thread.  

Can someone please direct me to a thread that contains this, so I can figure out what I need to change?  Any recommendations on the electronic ignition?  

I know I'm going with a Traxxas 4033 carb and will make something like the carb adapter on sheet 14.


----------



## Brian Rupnow (Jun 30, 2020)

Get hold of Roy Sholl at S & S engineering. He has everything you need if you want electronic ignition.


----------



## CFLBob (Jun 30, 2020)

Brian Rupnow said:


> Get hold of Roy Sholl at S & S engineering. He has everything you need if you want electronic ignition.



Thanks, Brian.  Found them and will send Roy an email.

Did you happen to see the PM I sent you?


----------



## Brian Rupnow (Jun 30, 2020)

CFLBob--No, I didn't see it. There is something not right about the private message function on this site. i will look for it.


----------



## Brian Rupnow (Jun 30, 2020)

Bob--I lost all of my Webster files in a computer crash a couple of years ago. I did find the message you sent me. What exactly did you want drawings of? I still have the original plans downloaded from the internet. If it's only the valve I can do up a drawing for you very quickly, no charge. I'm not real certain what you are looking for.


----------



## CFLBob (Jun 30, 2020)

I was looking for a tutorial on how you make the valves and valve cages, but I think I found one about the valves since I wrote.  I found a post you did (2016?) on making valves for another engine.  I basically copied that off into a Word document on my PC and put images inline. 

The parts are all different from the Webster, but I think the method for making the smaller pistons would transfer.


----------



## minh-thanh (Jun 30, 2020)

*CFLBob !*





__





						Introducing ... the "Steel Webster"
					

In aluminum, I have broken 3 flute 6-32 taps.  Ended my misery in a hurry using 2 flute since. Maybe do the same in steel!




					www.homemodelenginemachinist.com


----------



## CFLBob (Jul 1, 2020)

Thanks, Minh Thanh.  Looks useful.

I've seen the thread, but it didn't come up in my searches.


----------



## a41capt (Jul 1, 2020)

CFLBob said:


> I was looking for a tutorial on how you make the valves and valve cages, but I think I found one about the valves since I wrote.  I found a post you did (2016?) on making valves for another engine.  I basically copied that off into a Word document on my PC and put images inline.
> 
> The parts are all different from the Webster, but I think the method for making the smaller pistons would transfer.


Bob,
Brian’s method of turning the valve stem, or for that matter ANY thin part on the lathe, is the best idea since sliced bread!  While you’re making your valves, and before tearing down your turning setup,  I would suggest making a third valve and converting it to a valve seat cutter by adding some cutting edges into the valve face.  Far better that attempting to cut the valve cages accurately on the lathe, and decreases the issues of “leaky valves” when you’re attempting to get your first ”pop”after completion!

John W


----------



## CFLBob (Jul 19, 2020)

What a day.  I've been working but haven't had anything complete enough to post pictures of.  I ran a thread about how my drill chuck was falling off its taper way too often and got some suggestions that seem to have fixed it.  Then I broke one of my important drill bits in my #1-60 set and had to order a replacement set.  Today, I came back here to post the latest advancement on my Webster and find I'm locked out of everything.  Every place said I didn't have privileges to post.  It said my email didn't work.  First I've heard of it.  Too bad the hundred spams a day I get don't know it doesn't work.  That would save a lot of hassle.

Did you know that if that happens there is no way to ask for help?  I was still logged in it just wouldn't let me do anything.  I had to use an old, rarely used email address I have to be allowed to post this. 







The temporary screws are just to hold the parts together for this picture.  I think there's a few different pieces of hardware I need to order for this.  Time to get an order together from Bolt Depot or someone. 

On to the valves and the valve cages.


----------



## Brian Rupnow (Jul 19, 2020)

CFLBob--just a heads up---You will suffer greatly if you don't put gaskets between all three pieces. A piece of brown paper bag with grease on it will do. If you try to use any of the conventional gasket goo's, it will squeeze out on the inside and bugger up how your valves seal.


----------



## awake (Jul 19, 2020)

Brian, interesting point. On my Webster, I had assumed I would need to use some sort of gaskets, and was trying to find something thin enough not to throw off the compression too much. I'm glad to know about the brown paper bag & grease solution!

But as it worked out, I wound up not using gaskets on any of my Webster. Instead, I used a succession of wet/dry sandpaper on a piece of glass (for flatness) and polished all of the mating faces in the valve block and between the block and the head. To my pleasant surprise, I succeeded in getting good compression without gaskets!

Of course, whether or not I would get that lucky the next time around is up for considerable debate ...


----------



## CFLBob (Jul 19, 2020)

Brian Rupnow said:


> CFLBob--just a heads up---You will suffer greatly if you don't put gaskets between all three pieces. A piece of brown paper bag with grease on it will do. If you try to use any of the conventional gasket goo's, it will squeeze out on the inside and bugger up how your valves seal.



Thanks!  Without the valves and valve cages, it's a ways from done.  

I just wonder if there are any brown paper bags around anymore.  My groceries have been in plastic only for years.


----------



## Sprocket (Jul 19, 2020)

Try  Permatex " Form-A-Gasket" available in the hardware store. Paste stuff that seals very well. Just have to be careful not to overdo it (like everything else) so it doesn't plug your openings.
Doug


----------



## werowance (Jul 22, 2020)

i also did not  have to use gaskets on the valve blocks.  once the cages were pressed and locked tighted in place i used a improvised surface plate and sand paper as well just like awake describes above which brought the cages down to the same as the aluminum blocks.   used a little blue to tell when i just hit home with them.  they sealed up just fine.  i was surprised about that but it did work.


----------



## werowance (Jul 22, 2020)

here are some pics that might help.

post 198 on my build




__





						Werowance builds a webster
					

ok, so I'm on hold for a few days until my reamer arrives.  I switched over to the piston and drill/reaming on it and found out that it also has the same size hole to ream as the valve guide so now its on hold.  all I can do now is either start looking at making a gas tank or start working on an...




					www.homemodelenginemachinist.com
				




but id say grease soaked paper would make good gaskets as Brian said if you do need them.  but with the surface plate they sealed up nicely for me.


----------



## werowance (Jul 22, 2020)

oh, and sorry for posting so much but one more thing,  Brian gave me some direction on a jig to hold the crank pin in place to drill the hole in the flywheel for timing.  it worked great.  its in my build but  i think it was an awesome trick he gave me.


----------



## CFLBob (Jul 23, 2020)

werowance said:


> oh, and sorry for posting so much but one more thing,  Brian gave me some direction on a jig to hold the crank pin in place to drill the hole in the flywheel for timing.  it worked great.  its in my build but  i think it was an awesome trick he gave me.



I'll go look at the build thread. 

I went to start on the valves.  Changed the cutter on the lathe and lined it up a bit differently.  When I went to turn on my lathe, it wouldn't turn on.  This is my Sherline, which is about 1/10HP, a DC motor with a speed controller.  Since it didn't start running poorly, it just died, I figured it was the controller and not brushes.  Took about a day to find out it was just the on/off switch.  I had a switch in my pile of junk parts and got it running with only about a two day interruption.

I had figured I'd make a test valve first before I went any farther, working on Brian's approach.  







I should have time to get back to this today.


----------



## BaronJ (Jul 23, 2020)

CFLBob said:


> I spent entirely too long deciding what to build for my first IC engine and finally decided to go with the Webster while waiting for George Britnell to finish his plans for the Holt 75.
> 
> Last weekend (11th/12th) was spent tracking down and ordering materials and I had it all by Friday.  I didn't get everything, but enough to do a really good start on the engine.  In particular, the parts labelled brass and bronze seemed hard to get small pieces of.  I need to find a good source for that.
> 
> ...



I use citric acid (Lemon Juice) for de-rusting,  its not as vigorous as some. If you forget to take it out, it doesn't mater since it doesn't affect the parent metal like some.


----------



## CFLBob (Jul 23, 2020)

Does lemon juice take longer than overnight?  

I guess most of the time being in there two days instead of one isn't a big deal for me.


----------



## werowance (Jul 23, 2020)

muratic brick acid from the hardware store on a qtip works well for removing surface rust


----------



## CFLBob (Jul 24, 2020)

Well, this ain't happening.  This is as close as I can get a cutter to the valve to cut the 92 degree included angle on the back of the valve.  






This is the test valve on my Sherline micro lathe using their part number 1270 compound slide.   I thought this would be a good task for the Sherline because a 1" long part with stem that's .093 is a small part and the Sherlines are good at small.  The problem is that the compound slide just won't let me cut that 46 degrees on the end of that shaft.  I can't get the cutter within an inch of the part.  

Maybe if it was much longer blank that I started with, but I thought being 50 or 60% longer than needed was all I needed.  Besides, when I started this, I only had a bit over 3" of 1/4" drill rod available, so I cut it in half.  I since bought a 3 foot long piece of rod so I can make the blanks as long as I need to.  

Brian, I'm using the method you posted back a few years ago for the valves for another engine that were bigger than the Webster valves.  This compound slide won't position the cutter as in your method.  It looks like I start over with a longer piece on my 8-1/2 x 20 lathe.


----------



## BaronJ (Jul 24, 2020)

CFLBob said:


> Does lemon juice take longer than overnight?
> 
> I guess most of the time being in there two days instead of one isn't a big deal for me.



Hi Bob,

Citric acid is much more gentle !


----------



## BaronJ (Jul 24, 2020)

CFLBob said:


> Well, this ain't happening.  This is as close as I can get a cutter to the valve to cut the 92 degree included angle on the back of the valve.
> 
> View attachment 118110
> 
> ...



Ah the price you pay !
Now if you used HSS and not carbide inserts, you would know how to grind a lathe tool to do this job !


----------



## Sprocket (Jul 24, 2020)

BaronJ said:


> Ah the price you pay !
> Now if you used HSS and not carbide inserts, you would know how to grind a lathe tool to do this job !


You could try making the head first at the right end of the part, leave enough to face off later, use a center to support the end if needed.
Doug


----------



## CFLBob (Jul 24, 2020)

BaronJ said:


> Now if you used HSS and not carbide inserts, you would know how to grind a lathe tool to do this job !



I think it's easier than that.  I think all I need to is rotate the cutter I used to get to that first picture (post 261).  A 60 degree triangle for cutting threads would be an even easier cutter.


----------



## stevehuckss396 (Jul 24, 2020)

Flip the cutter to the other side of the tool holder and reverse the angle so the cutter is behind the work and run the lathe in reverse. Then cut from the back side.


----------



## stevehuckss396 (Jul 24, 2020)

You are not cutting the end of the stem, never mind.


----------



## CFLBob (Jul 24, 2020)

I went with the 60 degree cutter used for threading.  The compound slide is useful because of its accurate scale, and a quick check in CAD confirmed I thought of the angles correctly - the cutter should be 14 degrees off from straight into the part.  






Yes, I did move the valve a little to the right in the chuck.


----------



## Bill Lawson (Jul 25, 2020)

I made 4 or 5 valves and failed. I finally decided that .094 thou diameter was too long without deflecting and bending. My solution was to center drill the end and use a live center. I think that I left the shaft on the long side to allow clearance for the tool space between the tool and center. After turning and finishing the .094 stem I then used a parting tool to part the valve from the stock. Chucking on the .094 dia with the head of the valve in the chuck or collet it was easy to machine the .094 stem to length


----------



## awake (Jul 25, 2020)

CFLBob,

Looks like it worked - well done. Something to keep in mind - trying to cut this with effectively a form tool can lead to chatter. I don't know the Sherline setup, so don't know if you have another option - but if you can set the compound to the angle, then turn the tool straight, that would let you take a single-point cut rather than a form cut.


----------



## CFLBob (Jul 25, 2020)

I'm following a technique the Brian Rupnow posted a while back, '16 I think, and he recommends cutting it in thirds.  This one is 0.9" long, so I made a mark at 0.9 and 0.6 and 0.3 and cut to those.  The Sherline is a micro lathe, 3" over the bed, and only about 1/10 HP, so I take small cuts, like .005 (radius) and just turn the crank a lot.  My micrometer says those segments are all about .005 oversize diameter.  Brian said to shoot for .003". 

This was intended to be a practice piece to get through little problems like I've found.  At this point, there's a chance it will come out usable.  I might keep it as souvenir if it turns out good.


----------



## Brian Rupnow (Jul 26, 2020)

The biggest pucker factor is trying to stay .003" to .005" oversize on the stem---all three sections. If you go undersize on any of them, start over again. If you leave more than .003" oversize it seems to take an incredibly long time to sand that down to the desired diameter. One thing I do, before I set up to cut a valve, is to drill and ream a small piece of scrap to the desired diameter, and use it to check the progress of your sanding on the stem. This is one of the areas where your micrometer may lie a little bit. I have, in the past, made valves that when measured with my micrometer SHOULD fit into my valve guides, but in reality were still a bit too large.--Half a thou can make a huge difference to the fit.


----------



## CFLBob (Jul 26, 2020)

Brian,  I took that series you posted back in '16 and made a document in Word, then printed it out to work by.  First thing I did was make a tool like the one you show, a 3/4" diameter, 1" long piece of round bar, with an axial hole reamed to .094 - I'm changing all the dimensions to the Webster's smaller valves.  

We had company today so I didn't try to start the sanding.


----------



## minh-thanh (Jul 26, 2020)

All the engines I did: I usually made the valve body a little smaller than the valve seat, which would make the valve and valve seat "easy" to seal.
Especially with Atmospheric Intake Valve , Because the valve is only kept closed to the valve seat by a very very slight force of the spring


----------



## CFLBob (Jul 29, 2020)

I proceeded slowly with the sanding strip until it appeared that the area closest to the back of the valve (all the way on the left in the pictures above) was staying larger than the sections farther along the stem, meaning the stem was tapered.  I tried a narrow file just in that area and was able to reduce the diameter.  

I've put a video up on YouTube that shows a test fit of the valve stem diameter checker and the stem on my test valve.



What I'm trying to show is that the valve seems to fit tighter just before the taper about a tenth or eighth of an inch.  My micrometer says the valve is undersized there.  With the tester around the middle of the stem, it spins easily.  Up near the tapered part of the valve it moves but doesn't spin freely.

I have a hard time judging if this is the proper fit.


----------



## Misterg (Jul 29, 2020)

CFLBob said:


> What I'm trying to show is that the valve seems to fit tighter just before the taper about a tenth or eighth of an inch.  My micrometer says the valve is undersized there.  With the tester around the middle of the stem, it spins easily.  Up near the tapered part of the valve it moves but doesn't spin freely.



I  don't think you need to worry about that last tenth of an inch, as the ~0.11" of the valve stem nearest the head will be in the large diameter valve throat , not in the guide.


----------



## CFLBob (Aug 11, 2020)

Just an update.  Dropped back to do the valve cages.  Interruptions from tropical storm Isaias and the normal amount of fixing crap around the house.  Next is to make the real valves.   Had them inside the house, so I posed them on my keyboard with the test valve.


----------



## werowance (Aug 11, 2020)

Bob, the valve and cages look much cleaner and nicer than mine.  id say yours will have no problem starting and running.  just use the seat cutting tool when done,  dab a little blue on the brass where the valve hits the seat and twirl the tool by hand and just make a small cut by hand until the blue is gone and you have a brass line showing all the way around the seat.  i thought you had to have a wide seat like in a chevy 350 3 angle valve grind job or something but Brian R told me the smaller the seat surface the easier it was to get it to seal.  and that prooved to be correct.   i guess a 350 is putting a lot more compression than the webster is lol.


----------



## CFLBob (Aug 11, 2020)

I think I'm going to try the method in Brian's post that I saved.  He just puts the valve into the cage with some lapping compound and then twirls it by hand.  I'll see how that looks.


----------



## Brian Rupnow (Aug 11, 2020)

Don't try my method of lapping until after the valve guide is pressed and/or Loctited into place. They will distort a minute amount, and that amount will be enough to let compression escape. Do the valve lapping after the valve cage/guide is in place and the fuel/exhaust admission holes have been drilled.


----------



## CFLBob (Aug 11, 2020)

Brian Rupnow said:


> Don't try my method of lapping until after the valve guide is pressed and/or Loctited into place. They will distort a minute amount, and that amount will be enough to let compression escape. Do the valve lapping after the valve cage/guide is in place and the fuel/exhaust admission holes have been drilled.



Thanks, Brian.  I didn't get that from the thread I copied.


----------



## CFLBob (Sep 9, 2020)

Gosh, it has been a long time since I updated.  I'm stuck on the silliest of parts - the springs.  I'd made one or two before this, but never grappled with how much smaller do you need to make the diameter of the spring so that it doesn't end up too big.  I've made four versions of the one light wire spring; three too big and one too small.  The too big springs seemed to expand 1/16" diameter - from the 3/16 form to 1/4" when I released them or if I heat treated them on the form.  So I wound one on a 1/8" form.  It hardly expanded at all.  

All along I had this idea that if wrapped the wire tightly on a form and then clamped the wire in place with screws, it would be the fix.  So I took a piece of 3/16" drill rod, cross-drilled it and tapped it for two #2-56 screws.  After the heat treatment, I took it out and it opened up to close to 1/4", too. 






The only reason to make the springs precisely to size is because the valve retainers are 1/4" diameter with a 3/16" part that goes into the spring.  The 1/4" valve retainers fall into the spring and can't work properly.  I could make the retainer 3/8" with a 1/4" nub and I don't think it would make a darned bit of difference, but I've been trying to make it like the prints.  I think I move on to that today.

Aside from that, the valve cages are pressed in, the valves lapped, and I've been working on other parts.


----------



## awake (Sep 9, 2020)

Bob, you mention heat-treating - what type of wire are you using?

For my Webster, I made my first-ever springs following the original Webster plans, using music wire of the size called for there. With the music wire, no heat treating was involved. I describe the process here: Introducing ... the "Steel Webster" (post #49). Unfortunately, I apparently did not write down the size of the arbor I used, but I can measure it when I get back home.


----------



## CFLBob (Sep 9, 2020)

I'm using music wire - I bought what will be a lifetime's supply of .015 wire on another project and made a couple of springs. 

I've been going by this one tutorial by a camera technician:


			Making Springs on the Small Lathe
		


He says he puts his springs in an oven at 450F for an hour and then lets it cool slowly.


----------



## awake (Sep 10, 2020)

Bob, I measured the mandrel I used - it is .155". I used this mandrel for both the intake spring, using 7 turns of .013" music wire, and for the exhaust spring, using 9 turns of .022" music wire - both of these as called for in the Webster plans. I was pleasantly surprised by how well they turned out, since this was my first experience with making springs.

As noted in my build log, I made and used a simple "gripper" to guide and keep tension on the wire and set the lathe up to the closest tpi for the resulting spring. A couple of turns by hand to establish a flat beginning, then engaged the half nuts, let it turn the 7 or 9 turns, disengaged, and a couple of more turns to establish a flat ending. It helped tremendously that my lathe goes down to 30 rpm at its low end - much faster and I would have had difficulty controlling it. (If I didn't have the low speed, I would have turned the spindle by handle.)


----------



## CFLBob (Sep 10, 2020)

I like several things about that approach.  Certainly neater looking than mine; the gripper takes the place of the needle nose pliers I was using, and setting the lathe up to thread guarantees good spacing.  Drilling a hole for the wire at the start never occurred to me.  I had considered using my lathe to cut a groove in the tool of the right thread pitch and laying the wire in the groove.  7 turns in 5/8" long is 11 TPI.  That would not have the couple of tightly spaced turns you have.  

My small mandrel (the spring that didn't expand and is therefore too small) was the 3/16 rod I have turned down to .135 (I called it 1/8" above - that's wrong).  That number wasn't completely PFA; I figured that the 3/16" expanded 1/16" diameter, so I took .188 - .062 and got 1/8".   Then I thought that if it ended up a bit over 3/16" that would probably help, just not too much over 3/16" and settled on .200 final diameter.  That got me to .138.  

Thanks for the info.  I need to think about it.  The option of just making the retainers a little larger is easy and gets me out of the hole.   I have plenty of 1/2" CRS to turn down for a couple of retainers, but not much 3/16 rod to make a .155 mandrel from.


----------



## awake (Sep 11, 2020)

I turned my mandrel down from something a good bit larger - at least 3/8", maybe 1/2" diameter. My well-worn workhorse lathe has a 10" 3-jaw chuck and an 8" 4-jaw chuck - a wee bit on the large side for model engine work, and the 3-jaw in particular is not good at holding anything much under 1/4" diameter. I do have a small 7x14 lathe, and its chuck works beautifully for holding small pieces ... but no power feed, oddly calibrated (?!) dials, small DOC, PITA tail stock ... I tend to turn even the small parts on the big lathe, if I can figure out how to hold them. (One of these days, a collet chuck ... one of these days!)

Fortunately, I have a lot of mystery steel - which is perfectly suitable for an application such as this - in a variety of sizes from around 5/16" to 1" range, scavenged from various sources. Thus I don't mind turning down a 3/8" rod to a .155" mandrel, and on the big lathe it takes less time to do that than it would to turn a 3/16" rod to .155" on the 7x14!


----------



## CFLBob (Sep 12, 2020)

I realized I had a long length of 1/4" rod that I got at Home Depot.  Mystery Steel for sure.  I made a third fixture: .155 diameter and with two ways of fastening the wire.  First one is the hole through the mandrel and the second is the tapped 2-56 screw I used on the other one.  






I have two ways of threading: one has a minimum speed of 100 RPM and the other has a minimum of 200 (it's CNC and that's a Mach 3 limitation - IIRC).

I know you just used it off the mandrel, but I'm still a bit unsure, since the guy whose instructions I used says to heat treat it.  Either way I cut off the ends first.


----------



## Brian Rupnow (Sep 12, 2020)

You don't have to heat treat it---but--it will gradually lose it's strength after prolonged use if you don't. The heat treating "seals in" the tensile strength of the music wire.


----------



## CFLBob (Sep 12, 2020)

Thanks, Brian, that's good to know.  It had just completed its heat soak when this arrived.


----------



## awake (Sep 13, 2020)

Brian Rupnow said:


> You don't have to heat treat it---but--it will gradually lose it's strength after prolonged use if you don't. The heat treating "seals in" the tensile strength of the music wire.



Ah, that's interesting! Thanks, Brian.


----------



## CFLBob (Sep 13, 2020)

Saturday night is church, so I was back out of the shop while the spring cooled.  When I took the spring off the mandrel, it worked better than any of the others.  Here's the assembled intake valve assembly with the winding fixture next to it.






The retainer fits inside the spring easily, but the spring is a bit tight on the valve cage.  I screwed it onto the cage.  The other issue is the retainer at the top isn't close to the .040 of the hole, its' a piece of wire from the shop that's under .030.  A wire chart says that .040 is #18 wire, and I probably have a little around here somewhere.


----------



## CFLBob (Sep 13, 2020)

Finally, both valve and spring assemblies (same "these aren't the final wires" comment as the previous).  The second spring in the drawings nearly matched one I had in the shop from somewhere or other (probably a gun project), so I just cut it to length.  






Along the way, I got the muffler to mostly-done, except for one cut (to trim off the end at the 30 degree angle).  I'm debating whether to do that with a slitting saw on my small mill or just with a hand jeweler's saw.  






I honestly don't remember if I finished any other parts while getting these done.  I've been putting the parts in a plastic tub on the bench and I think assembling this is going to reveal some things I haven't done.


----------



## awake (Sep 14, 2020)

Getting close!


----------



## werowance (Sep 14, 2020)

i used my table belt sander to cut (sand) the angle on my exhaust pipe


----------



## awake (Sep 14, 2020)

Hmm ... I looked back on my build log for my modified Webster, and realized I never finished it - just had a few miscellaneous odds and ends to add, one of which was the exhaust.

Then I looked at the pictures I took ... and apparently I took none when I was making the exhaust. 

As best I remember, I turned the part as per the plan (attached), set the part in my vise, protected by some wood (? I think?) at the proper angle, and milled it to the correct angle. I think. Apparently, if I didn't take pictures, I can't remember exactly how I did it!!


----------



## CFLBob (Sep 14, 2020)

werowance said:


> i used my table belt sander to cut (sand) the angle on my exhaust pipe



For some reason, that didn't occur to me, although I've done it to put tapers on other things, or to cut small corners on pieces.  



awake said:


> As best I remember, I turned the part as per the plan (attached), set the part in my vise, protected by some wood (? I think?) at the proper angle, and milled it to the correct angle. I think. Apparently, if I didn't take pictures, I can't remember exactly how I did it!!



My first thought was to put it in a milling vise with one end held up the right number inches to get that angle (kinda like a sine plate).  Then I started worrying about it being destroyed by the cutting forces.  I have a fine tooth slitting saw blade for my Sherline and it seems that the forces aren't that bad, but it's a CNC mill so I've never turned the wheels by hand where I can feel it.  I could drill a hole into a chunk of wood that needs to clamp the piece, but not too hard.  Drill the hole, then split the wood in half and use screws to hold it together?


----------



## awake (Sep 14, 2020)

The wood is a good idea. I would start with two pieces with a bit of shim in between (a layer or two of construction paper or something like that) - pop a couple of brads in, or something like that, to hold them together. Drill the hole right through the center where the shim is. Separate and remove the shim. Now you have a jig that will put a bit of pressure on the piece to hold it secure. Voila!


----------



## awake (Sep 14, 2020)

Oh, missed the reference to screws - yes, you could screw it together before drilling. You could use the screws to reassemble and put pressure on the part to hold it ... or you could let the vise apply the pressure. Either should work fine, I would think.


----------



## werowance (Sep 15, 2020)

i should also add that on mine,  I made a 2 piece muffler.  I had brass tubing like you get in a pack from a hobby shop which made up the larger portion of the muffler with the angle tip,  then the base of the muffler I used a piece of brass and turned it, rounded over the base piece, drilled the hole through and soldered the 2 pieces together.  but I sanded the angle on the tubing first before joining the pieces together.
circled in red you will see the solder line.  but your idea sounds like a great way to do it as well.  I was just trying to use up some scrap stock on mine


----------



## CFLBob (Sep 15, 2020)

It's nice looking.  Mine is a bronze rod that I got from Online Metals.  It's sold as 3/8 but with a note that it's oversized, I think it's really 13/32.  It's OK but I have to turn it down to be anything.  Not knowing how much room I had between the muffler and what's behind it, I just made it like the prints.   

I've ignored the oil cups until now.  I'm wondering how people handled that; if you guys made all the little cups or just put a drop of oil in all those holes before starting it up.  I'm sure it will be running for like a minute at a time.


----------



## werowance (Sep 15, 2020)

i did ball bearings.  I did do the oil cup for the cylinder but that's all.


----------



## awake (Sep 15, 2020)

Like Werowance, I did ball bearings for the main bearings, and for the bearing on the cam gear. I used a bronze bearing on the rocker arm, with a small hole for oil - I just put a drop in there, and it seems to last forever. Likewise a bronze bearing at the little end, and I put in the hole in the cylinder and piston ... but so far I have just been lining it up an putting in a drop or two of oil from time to time.


----------



## CFLBob (Sep 15, 2020)

I also got ball bearings for the main ones in the side plates.  I need to look at the others.  I remember the bronze bearings in the connecting rod, but that's about all.

Meanwhile, the wooden fixture worked as intended.  Setting up for the cut.






I cut a bit high of the full cut, so I lowered the blade about half its thickness and cut again.  Twice.  






Finally,






Like you said, Andy, I took pictures to remind myself how to do it.  If I ever need to cut close to a 30 degree angle on a piece of 3/8 stock, I have a fixture.  

For the other 99% of cuts like that, I have a technique.


----------



## werowance (Sep 15, 2020)

well, that's not what I had invisioned on the wood fixture but that really was a good idea.  thanks for showing that.

on the crank to rod I changed that a bit from drawings and did a ball bearing there as well.  but rod to piston is brass busing and I ran mine a lot with nothing more than a drip or 2 of oil in the hole  where the cylinder oiler goes.  but I did make sure the oil drops also hit the hole in the piston to run down on to the wrist pin area.  but id say if you omitted that oiler for now and just drilled the hole for where it goes would be fine.


----------



## CFLBob (Oct 3, 2020)

As usual, I keep working on stuff but not posting.  I started trying to understand how this all goes together.  

I ran into my first booboo.  I drilled the mounting hole in the cylinder head in the wrong location.  The tapped 10-32 hole in the bottom is supposed to be 0.688" from the inside edge of the relieved portion of the cylinder head and I put it 0.688 from the outside edge.  When I put it together, it looked like this:






I'm sure there will be more.  This is the area after I fixed it.  The valves and intake/exhaust manifold wouldn't mount before.  An extra hole on the bottom of part that nobody will ever see is the easiest kind of mistake to live with.






And a wider shot.  Just because.






I started looking into a fuel tank and asked myself if I'm using an RC carburetor, why not an RC fuel tank?  Webster says he uses a small one that holds like 1 oz of fuel.  My first search only turned up model fuel tanks that hold quite a bit more, like even 8 ounces.   

I keep asking myself "now where does this go?" or "what's this?"


----------



## werowance (Oct 3, 2020)

well, does the hole actually make it to line up with the oil hole in the piston to hit wrist pin at any point during the rotation?  even just enough to see part of the hole?  if so id say it will be ok since the engine doesnt run for long periods of time.  the oil cup though will have to have a little more clearance to clear the fins on the shank where the trheads are..

also does the piston ring groves run over this hole? if it does then might be a problem. but if you rotate the assembly without the rings on it and the ring grove shows through the hole then i might be conserned about it catching


----------



## CFLBob (Oct 3, 2020)

I think you're thinking of the hole in the cylinder toward the left of the fins?  It's not that one.  It's the tapped hole on the bottom.  In this picture, I made it 0.688 from the right side, not as shown.


----------



## werowance (Oct 3, 2020)

doh,  sorry, i understand now.  yeah your right no body will see it on the bottom.  plug an lock tight it if your worried about it being seen but otherwise it shouldnt be any problem.  one thing on that particular area,  mine vibrates loose. the 2 side screws and the 1 bottom screw all gets loose after a bit of running.  so just a heads up if yours starts moving,  its probably not because of the extra hole,  i think its just because of the design.  or in my case maybe the person who built it......


----------



## minh-thanh (Oct 4, 2020)

CFLBob said:


> View attachment 119821
> 
> 
> 
> ...



Your engine is a lot nicer than my first 4 stroke


----------



## CFLBob (Oct 4, 2020)

minh-thanh said:


> Your engine is a lot nicer than my first 4 stroke



Thanks.  It will get a lot prettier when it runs!   I was going to say if it runs, but I'll be positive.


----------



## CFLBob (Oct 4, 2020)

One of the things I needed to do was make up a little piece that's not part of Webster's plans to fit the counterweight that I copied from Brian Rupnow and adapt that to drive the connecting rod.  






There's another piece I need to make because of a mistake I made around post #44 where I misinterpreted things and instead of making a 1/4" hole to hold the camshaft, I drilled it out for ball bearings.  I'll make a brass adapter to fit in that hole and drill a quarter inch hole axially.


----------



## CFLBob (Oct 5, 2020)

I have a question for those who have put a Webster together. 

Back when I was working on the side frame, when I went to make the hole for the camshaft, I made the mistake of making it to fit a ball bearing set that I had 3/8 OD, 1/4 ID instead of just plain 1/4 (reamed) like the drawing says.  I hadn't understood that the shaft is stationary in that hole and the cam rotates on it. 

Today I made a little bushing to fill the hole and present a reamed 1/4" hole for the camshaft.  






This is the oversized hole the bushing and the camshaft.  As you can see, I left lip on the bushing that will stand proud of the side frame either on this side or the inside.  I left it 1/32 thick.  It looks like that should be OK on the outside because the conn. rod, the counterweight and the all that is far from the side plate. Is there any reason to either put that shoulder on the inside, or get rid of it completely?  

And while I'm here, I have a shoulder like that on my ball bearings for the crankshaft.  Are those good on the outside, where they are?  You can see the one above the camshaft hole.


----------



## scottyp (Oct 5, 2020)

I had a little mishap when I drilled same hole. Long story, but the hole ended up being at an angle and off of the correct location. I was able to make a tight press fit plug (without a lip) and re drill it correctly and it has been OK.  As long as you have the clearance for the lip, I’d hide it on the inside.  Either will be fine. Just make sure your bushing is a tight fit, some locktite will help ensure that it doesn’t come out.  The lip is really only helping in one direction and there isn’t a ton of force on the shaft so it may not be super important.  You could also recess it a bit if you had an end mill with the same diameter as the flange.  But really not a big problem, nobody will care when the thing comes to life.

I’d run the flanges of your bearings on the inside of the frame since all of the crankshaft spacers are between the frame sides and the is what locks in everything.  And there is not a spacer between the ignition cam and the frame and I wouldn’t want to have the one little set screw be what holds everything in the right place.


----------



## CFLBob (Oct 6, 2020)

scottyp said:


> View attachment 119868
> 
> 
> I had a little mishap when I drilled same hole. Long story, but the hole ended up being at an angle and off of the correct location. I was able to make a tight press fit plug (without a lip) and re drill it correctly and it has been OK.  As long as you have the clearance for the lip, I’d hide it on the inside.  Either will be fine. Just make sure your bushing is a tight fit, some locktite will help ensure that it doesn’t come out.  The lip is really only helping in one direction and there isn’t a ton of force on the shaft so it may not be super important.  You could also recess it a bit if you had an end mill with the same diameter as the flange.  But really not a big problem, nobody will care when the thing comes to life.
> ...



Thanks, Scotty.  That's helpful.  

The thing I'm spending the most time on is trying to visualize how that area between the two frames goes together.  Would you have a picture of that?  Did you have your own build thread here?


----------



## scottyp (Oct 6, 2020)

Scotty's Webster
					

So I finally have some progress on my Webster so I thought I'd start a post to keep me motivated.  I built a few basic steamers and a NGEZ maybe 10 years ago with "OK" results and have had the Webster 4 stroke in mind for quite a while.  The kids are older and I have since gained more milling...




					www.homemodelenginemachinist.com
				




Not a super detailed build thread but there are pics.  My frame rails were a little thinner than the plan so I made my bushings and spacers to fit.


----------



## CFLBob (Oct 6, 2020)

scottyp said:


> Scotty's Webster
> 
> 
> So I finally have some progress on my Webster so I thought I'd start a post to keep me motivated.  I built a few basic steamers and a NGEZ maybe 10 years ago with "OK" results and have had the Webster 4 stroke in mind for quite a while.  The kids are older and I have since gained more milling...
> ...



Very useful.  My brain works better seeing pictures than engineering drawings.


----------



## CFLBob (Oct 11, 2020)

Quick Traxxas Carburetor question.  Is there a preferred in/out?  It seems like looking into it along the big axis, it's symmetrical.  I can see the lever close the air pathway, and the fuel is independent.  

I started messing with ideas for an adapter down to the size of the port the Webster carburetor would attach.  Started testing it and it got stuck.







This would be the fuel/air mix going into the engine on the left and the air intake on the right.  The fuel intake is on the far side of that tube on the upper left.  

Does it matter?


----------



## scottyp (Oct 11, 2020)

That is how that carb is designed.  I made my adapter out of brass with a loose sliding fit and tried to use the o ring as the seal.  My carb had screws on the side of the barrel and i used them to secure the carb to the adapter.  Look at the first couple of pics in my thread.


----------



## Brian Rupnow (Oct 11, 2020)

Yes it matters, and yes, you have it right.---Brian


----------



## CFLBob (Oct 11, 2020)

Thanks, Scotty, Brian.  

I'm making progress, slowly, but there aren't many things remaining before I try to start this up.


----------



## CFLBob (Oct 18, 2020)

I found a mistake in my counterweight.  Apparently I didn't ream the hole the crankshaft goes into, so even though I tried Red LocTite and spent days waiting for it to cure, it broke.  Twice.  I had enough time to order some 680 LocTite last weekend and get it delivered while waiting for the joints to cure.  

Today I thought instead of making the counterweight over, I'd enlarge the hole and make a bushing for it.  I made the hole the counterweight 3/8" (reamed to size) and then bored the bushing to 5/16 for the crankshaft.    






This is everything before assembly.  I mounted the bushing with the 680, and will polish the shaft a bit more to make sure the scratches don't bind as I try to put the crankshaft in place.


----------



## coulsea (Oct 18, 2020)

Adding a bush has made the assembly even weaker. pin it and it should be ok


----------



## CFLBob (Oct 18, 2020)

coulsea said:


> Adding a bush has made the assembly even weaker. pin it and it should be ok



Could you explain how the bushing makes it weaker?  

Do you mean to pin it through the bushing and shaft, drilling in from the side through the centerline of the thickness of that circular sector?


----------



## coulsea (Oct 18, 2020)

it now has two joints instead of one. I would pin from one of the angled sides (shortest distance) through the bush and shaft and at least 1/8 into the other side.


----------



## CFLBob (Oct 18, 2020)

Thanks.


----------



## L98fiero (Oct 19, 2020)

coulsea said:


> it now has two joints instead of one. I would pin from one of the angled sides (shortest distance) through the bush and shaft and at least 1/8 into the other side.


Maybe it's overkill but I'd lose the bronze bushing, replace it with a pressed in steel bushing and then pin it


----------



## CFLBob (Oct 19, 2020)

L98fiero said:


> Maybe it's overkill but I'd lose the bronze bushing, replace it with a pressed in steel bushing and then pin it



Well, it's a pressed in bronze bearing now.


----------



## CFLBob (Oct 20, 2020)

With the pressed in bronze bearing, I've gotten farther than I've ever gotten






I did this primarily to size the spacers on the crankshaft, left and right.  The washer on the right (ignition cam side) is .031 thick.  

Now for my dumb question of the day.  How do you put these things together and take them apart again?  I can't do it with hand strength alone.

I can't get this apart, and the only way I could press it together was to use an 18" Bessey-type woodworking clamp and a cap over the right end of the shaft.  I have no idea how to get the crankshaft out of those parts.

I need to take it apart because the flywheel isn't tight enough on the shaft.  While it all runs fine if I spin the flywheel when it's hooked up like this, if I put resistance on anything, the shaft spins in the flywheel or in the bronze bushing on the crankshaft throw.  I'm concerned the piston will cause enough resistance that the timing will get knocked out.   I'm going to peen the shaft in a few places so that the next time I put it together it will be twice as hard to put together.  At that point, it might never be taken apart again.


----------



## scottyp (Oct 20, 2020)

First, what parts had the tight fit that needed pressing together? At this point the only crankshaft related parts that should be stuck together are the crankshaft itself and the gear to the flywheel.  The crankshaft assembly should be able to slide out to the left fairly easily (looking at the rear of the engine in your pic).  The ignition cam should be a sliding fit, it is held in place with a setscrew later when it's timing is set.

Second, carefully read this from the plans and get your head wrapped around it before you drill for pins:
"Exhaust valve timing is set by rotating the crankshaft
counter-clockwise (as viewed from the cam side) until it is about 15 - 30 before
it's outward most stroke. It is then held in place while the flywheel is rotated C.C. until
the cam just starts to lift the exhaust valve off of it's seat. Clamp, lock, & secure everything
in place and drill the two roll pin holes as shown on the next sheet. If set properly, the
exhaust valve will close a few degrees before TDC."

Good luck - the timing will eventually make sense.

Also, maybe mark you gears with some white paint dots so you know where they need to be rotated when reassembling things, that will save a bit of frustration.

-Starting to look like an engine!


----------



## werowance (Oct 20, 2020)

on the flywheel it was just a sliding fit on mine,  then once I had everything done I drilled and put in a roll pin as per plans.  I did have to use a long reach drill to do it but that was pretty much the last step after everything was test fit.


----------



## CFLBob (Oct 20, 2020)

scottyp said:


> First, what parts had the tight fit that needed pressing together? At this point the only crankshaft related parts that should be stuck together are the crankshaft itself and the gear to the flywheel. The crankshaft assembly should be able to slide out to the left fairly easily (looking at the rear of the engine in your pic). The ignition cam should be a sliding fit, it is held in place with a setscrew later when it's timing is set.



Thanks, Scotty.  The parts that are the tightest are the ones that are supposed to be: the crankshaft in the ball bearings.  Pushing it through the second bearing (right in this picture) was what took the Bessey clone clamp (from Harbor Freight). I had let my head get ahead of reviewing the plans yet again. I've had the ignition cam on and off with its setscrew, that's not a concern.



werowance said:


> on the flywheel it was just a sliding fit on mine



That's what I have and what I was concerned about.  I need to RTFP again until they sink in better.   

Bob


----------



## minh-thanh (Oct 20, 2020)

*CFLBob !



*

You can use the hammer and a wooden  (it helps not to damage the outer part of the crankshaft )
Or you can use the woodworking clamp  to remove it.


----------



## scottyp (Oct 20, 2020)

OK, I did not have ball bearings in mind. Carry on.


----------



## CFLBob (Oct 25, 2020)

It took a while to get here due to tools on hand, but I have the flywheel pinned to the shaft.      






The crankshaft throw that's a sector of a circle had me a little mentally barfed up for a while.  Finally a little careful drawing in CAD got me how to align the throw to get the 15 degrees before TDC that the drawing says to work with.  Naturally, I didn't do this check until after I had made it the wrong way, so that it was 30 degrees before TDC.  I had to drill a second set of holes in the crankshaft to pin it properly. 






I have one of those digital angle gauges that I used to set the "downhill angle" on that to 8 degrees. 

My plastic gas tank from Tower Hobbies should be here tomorrow.  I'll need to get dimensions and plan a little stand for that.  And I need to learn how to set up my electronic ignition. 

I think all I need to buy is a set of points and some Glow Fuel.

*Edit to add:* I keep forgetting I need some gasket sheeting to make the head gasket.  Does anyone know if the kind of cardboard used as the back on a note pad would work?


----------



## BaronJ (Oct 26, 2020)

Hi Bob, Guys,

Yes it will work, though you would be better off with the proper material.  I've used a synthetic material with success.


----------



## werowance (Oct 26, 2020)

on mine, i ended up not needing a head gasket at all,  but an old tide soap box would work as well.   but min ran fine with no gasket at all.  my only problem was ignition timing vs valve time was done exactly oposite of what it should have been done.  once i corrected that it started right up.

now on starting.  will you be putting  a drill start lug on your crank?  i didnt what i used was a rubber disk i got at the auto parts / paint store.  its used for removing the glue or double stick tape on body trim and vent visors and such.  chucked it in my drill and just pushed it against the fly wheel and i turns it over pretty easily


----------



## scottyp (Oct 26, 2020)

I actually don't have a head gasket on mine either.  I did add some paper gaskets for the valve body parts as I could see a few bubbles in a couple of spots, but that was after my initial runs.  If you feel compression and the intake and exhaust seem to be working correctly, it will probably run without gaskets.  You should be able to tell if you have leaks and where they are.  Ultimately though, you may end up adding gaskets.  No big deal.


----------



## CFLBob (Oct 26, 2020)

werowance said:


> now on starting. will you be putting a drill start lug on your crank? i didnt what i used was a rubber disk i got at the auto parts / paint store. its used for removing the glue or double stick tape on body trim and vent visors and such. chucked it in my drill and just pushed it against the fly wheel and i turns it over pretty easily



I was just looking at some pictures of those yesterday.  Hadn't really thought it out, but I should.  

I don't think I've ever heard of or seen the thing you're talking about for removing the glue or tape residue.  Do you have a picture in your build thread?  Or some kind of product name I can search on?  



scottyp said:


> I actually don't have a head gasket on mine either.  I did add some paper gaskets for the valve body parts as I could see a few bubbles in a couple of spots, but that was after my initial runs.  If you feel compression and the intake and exhaust seem to be working correctly, it will probably run without gaskets.  You should be able to tell if you have leaks and where they are.  Ultimately though, you may end up adding gaskets.  No big deal.



Thanks, Scotty.  I used rectangles of brown paper, like Brian Rupnow suggested.  I haven't soaked them with oil, yet; I'm waiting to get closer to starting it up.  I'll probably get some gasket stock at AutoZone  while I'm up there.


----------



## Brian Rupnow (Oct 26, 2020)

For head gaskets I use 0.030" thick waterpump gasket from a local auto supply company. It is grey in color and comes in either rolls or sheets. Cardboard from a cereal box will work, I just don't know how long it will last because of the heat.


----------



## Cogsy (Oct 26, 2020)

CFLBob said:


> I think all I need to buy is a set of points and some Glow Fuel.



Why do you need glow fuel if you're running spark ignition? I'm (easily) confused...


----------



## CFLBob (Oct 26, 2020)

Cogsy said:


> Why do you need glow fuel if you're running spark ignition? I'm (easily) confused



I don't know that I do.  I was just planning for it.  

I'm way too ignorant about these things.


----------



## Sprocket (Oct 26, 2020)

You might try Coleman fuel with a little WD 40. ( Maybe 5%)


----------



## minh-thanh (Oct 27, 2020)

The engine can be used with gasoline with w40 oil
I often use a mixture gasoline - oil  for my all engines.


----------



## BaronJ (Oct 27, 2020)

werowance said:


> on mine, i ended up not needing a head gasket at all,  but an old tide soap box would work as well.   but min ran fine with no gasket at all.  my only problem was ignition timing vs valve time was done exactly oposite of what it should have been done.  once i corrected that it started right up.
> 
> now on starting.  will you be putting  a drill start lug on your crank?  i didnt what i used was a rubber disk i got at the auto parts / paint store.  its used for removing the glue or double stick tape on body trim and vent visors and such.  chucked it in my drill and just pushed it against the fly wheel and i turns it over pretty easily



Hi Guys,

I've seen old printer paper drive wheels used on a mandrel for that task.  I'm thinking of the plastic rubber covered type like those used in HP desk top printers.


----------



## werowance (Oct 27, 2020)

here is what I am using.  the link to ebay is very expensive.   think I paid about 15.00 for mine,  I bought it to remove the double stick tape from when I was removing vent visors from my wifes car a long time ago. - a starting lug would probably be better but I didn't do one and the disk works fine for me

on fuel I ran straight coleman camp stove / lantern fuel from wal mart.  runs just fine on that.

ebay link to the ruber disks.  don't buy this one because 191.21 is way to much,  maybe because it comes with the air tool as well.  I bought mine at napa auto parts and just chucked it in the drill









						Auto Body 4" Rubber Pad Air Power Pinstripe Molding Tape Cleaner Removal Tool  | eBay
					

Find many great new & used options and get the best deals for Auto Body 4" Rubber Pad Air Power Pinstripe Molding Tape Cleaner Removal Tool at the best online prices at eBay! Free shipping for many products!



					www.ebay.com


----------



## werowance (Oct 27, 2020)

here is the fuel.  Bass Pro and Cabellas also cary it. or used to anyway but I  know Walmart still does.





__





						Robot or human?
					





					www.walmart.com


----------



## CFLBob (Oct 27, 2020)

Thanks for the info on the pinstripe remover.  I've found them online at Walmart and Amazon.  I didn't check my AutoZone.  

And this little post got interrupted by about 90 minutes because I have a washing machine filling the kitchen sink.  Time to play plumber.


----------



## CFLBob (Nov 1, 2020)

Thankfully, the plumbing issue was resolved with a plumber's snake. 

I've been back to the Webster, resolving little issues one at a time.  Today, I put up a video to show a problem I've been staring at for a few days. 

I can turn the flywheel by hand and move the piston but during the compression part of the stroke the flywheel will slip and the crankshaft throw stop moving unless I drive the crankshaft throw by hand.  *There is no spark plug in the cylinder*, just a giant hole to the outside world so there's no real compression going on.

When the piston is coming out of the cylinder, it moves much more freely.  

My inclination is that it's not the cylinder because I think if that was too tight in that area, it would be just as hard pulling the piston out as pushing it in.  

The crank shaft throw isn't perfectly perpendicular to the shaft and has a little wobble.  I can watch the pin driving the connecting rod move in and out of the bearing a little during the rotation about 1/16" back and forth.  It seems pretty easy (I have oil in there) so I don't think it's that resistance. 

Comments appreciated.


----------



## Brian Rupnow (Nov 1, 2020)

As long as there isn't anything actually going 'kerthunk!!' when you turn it by hand, put a v-belt from an electric motor to the flywheel, coat everything with lots of oil, and let it run for an hour. That cures an amazing number of ills.


----------



## Sprocket (Nov 1, 2020)

Don't know how hard it would be to get the connecting rod separated from the crank throw, but then you could move the piston by hand, and maybe eliminate that as a reason for binding. I don't think the crank pin being in a visibly different position in the big end bearing at different parts of the rotation is a good sign...
and likely your problem. You've had other issues with that crank throw, and maybe it's all come together to bite you.
Doug


----------



## CFLBob (Nov 1, 2020)

Brian Rupnow said:


> As long as there isn't anything actually going 'kerthunk!!' when you turn it by hand, put a v-belt from an electric motor to the flywheel, coat everything with lots of oil, and let it run for an hour. That cures an amazing number of ills.



No kerthunk sounds.  I moved the throw maybe .010 away from the side and now I can spin it with my electric drill.  It has been running 45 minutes.


----------



## CFLBob (Nov 1, 2020)

Sprocket said:


> Don't know how hard it would be to get the connecting rod separated from the crank throw, but then you could move the piston by hand, and maybe eliminate that as a reason for binding. I don't think the crank pin being in a visibly different position in the big end bearing at different parts of the rotation is a good sign...
> and likely your problem. You've had other issues with that crank throw, and maybe it's all come together to bite you.
> Doug



I keep telling myself I could have made a half dozen in the time I've spent deciding if I need to make one.  It's running comfortably now, and when I swapped batteries after about 20 minutes, I tried by hand and it was definitely easier.


----------



## coulsea (Nov 1, 2020)

I have found that sometimes you need a bit more wriggle room here and there to stop binding. it the con rod has a bit of room to move from side to side in the piston it will allow for some wobble in the crank disk. a vertical upshur that i made would lose compression at the top of the stroke because the crank was pushing the piston sideways, compressing the oring on one side and creating a gap on the other, half a millimetre off each side of the con rod and it was fine, after a week of frustration trying to find the problem.


----------



## Brian Rupnow (Nov 1, 2020)

I might get some argument on this ---but--When I build an engine, (and I've built about 40 now) I hold everything to the tightest tolerances I can manage on a manual mill and lathe, both with DRO's. Consequently, these engines are generally quite "stiff" when they are finished. Some of the stiffness can be attributed to tight tolerances, some can be attributed to a "stack up" of tolerances. If I can turn them through a full 360 degrees without any definite interferences, then I oil everything up very well and run them for 1/2 to 1 hour with an electric motor and a v-belt drive. If they don't loosen up in that time, then I've made something wrong. Probably 95% of the time they loosen up quite considerably after "running them in" and are then ready to run on their own.---Not everyone agrees with this approach, but this is what works for me.---Brian


----------



## CFLBob (Nov 1, 2020)

Brian Rupnow said:


> I might get some argument on this ---but--When I build an engine, (and I've built about 40 now) I hold everything to the tightest tolerances I can manage on a manual mill and lathe, both with DRO's. Consequently, these engines are generally quite "stiff" when they are finished. Some of the stiffness can be attributed to tight tolerances, some can be attributed to a "stack up" of tolerances. If I can turn them through a full 360 degrees without any definite interferences, then I oil everything up very well and run them for 1/2 to 1 hour with an electric motor and a v-belt drive. If they don't loosen up in that time, then I've made something wrong. Probably 95% of the time they loosen up quite considerably after "running them in" and are then ready to run on their own.---Not everyone agrees with this approach, but this is what works for me.---Brian



Brian, you're one of the people I follow the closest on the HMEM.  I've seen you talk about running in an engine like that, and seen you do it in videos.  That was my goal all along.  

Like I said, I was able to get it to move a bit smoother every time I played with it and now it has run for at least a half hour.  A couple of days ago, if I turned the flywheel by hand, the crankshaft throw would stop moving,  now it completes every revolution.  The drill ran for an hour, but a few times the chuck loosened and the engine stopped moving.  It was while I was looking after something else (of course) so the drill ran five minutes or more without moving the engine.  I'm getting close to trying to start it and all the troubles that will fall out of that.


----------



## CFLBob (Nov 9, 2020)

Another week, another little bit of progress.  Back on the 1st, I finally said "tomorrow" I'd make a replacement crankshaft throw to replace the one that has been giving me problems for weeks.  The next day I thought it might make a nice accent to make it out of some brass I have, so that was a few hours.  It had to be 1/4" thick to fit where it goes, and I had some junk 1/2" thick brass I've had around for years and used to make test cuts on.  I thinned it down to 1/4" and was able to make a replacement fit in the space I had.  Because of a few factors involved with thinning the brass and proofing the CNC file, it took two afternoons to make this one.







With that pin at the top moved over to the brass one and once in place on the engine it looks like this. 






When it's moving, you can tell it's a different color, and when it's at rest, it's a bit more noticeable but I probably should have spent a day sanding and polishing it, then coating it in polyurethane varnish.  

I ran it with my drill driving it for another half hour today and the system seems to move OK.  The binding I had a couple of weeks ago seems gone.  

What's left?  I need a couple of inches of fuel line from the tank to the carburetor.  I need a little mount for the fuel tank; I understand that it should be around a half inch or so higher than the carb. so that the fuel flows without a fuel pump.  I need to get a set of points for the engine and hook up my electronic ignition.  I can get it to run with the electronic ignition spread around on the bench, but a box for it seems like a good idea.   Lastly, I need to grab a gallon of Coleman fuel and some WD-40.  I have spray cans around and someone on another thread suggested just spraying some of that into a plastic cup that measures out teaspoons.  My fuel tank holds 4 ounces and I don't think I'll put that much into it.


----------



## coulsea (Nov 10, 2020)

The top of the fuel tank should be level with the carb, it needs to suck the fuel up. I don't see any reason to put wd40 into fuel, i use 2 stroke oil, it is designed to lubricate a bore. the only reason that it is called 2stroke is that 4 strokes have oil in the sump and lubricate the bore from inside. a proper open crank engine will have a cylinder oiler that will again lubricate from the back.


----------



## Brian Rupnow (Nov 10, 2020)

Coulsea is right. Top of gas tank marginally below center of carburetor or it will constantly flood itself.--Gas runs down-hill from gravity. Forget the wd40 added to your fuel. Use a bit of 2 cycle oil added to it.


----------



## CFLBob (Nov 10, 2020)

coulsea said:


> I don't see any reason to put wd40 into fuel, i use 2 stroke oil, it is designed to lubricate a bore.



I actually have a practically unlimited supply of that.  Almost a gallon.  I have an outboard engine that's among the last ones made that injected that oil along with the gasoline.  It seems like a drop or two in a half cup of fuel would work. 

Back when I had my first boat, it was called 50:1 oil and the cans were sized so that you put one can in a 6 gallon gas tank.


----------



## minh-thanh (Nov 10, 2020)

W40 or 2 stroke oil: I have tried both, whatever is ok, just ... w40 is available for me so I prefer it


----------



## CFLBob (Nov 10, 2020)

Brian Rupnow said:


> Coulsea is right. Top of gas tank marginally below center of carburetor or it will constantly flood itself.--Gas runs down-hill from gravity. Forget the wd40 added to your fuel. Use a bit of 2 cycle oil added to it.



Brian, do you have a photo where you show the Traxxas carburetor on an engine?  Does the fuel inlet barb go on the bottom like this or the top?  I think I need a dab of sealant of some kind on where the carburetor adapter goes into the valve block assembly.  The carb rotates too freely in there for my taste.


----------



## Brian Rupnow (Nov 10, 2020)

You have the carb positioned correctly. You most smear a bit of green Loctite around the o.d. of the discharge side of the carburetor. It is 10 mm in diameter and fits into a reamed 10 mm hole. The Webster intake manifold as per drawing will not fit that carburetor. You need to make a male to female adapter.


----------



## CFLBob (Nov 10, 2020)

Thanks.  Not that it's important, but on the Webster that hole in the valve block is 5.5 mm (7/32"), so I have an adapter there.


----------



## werowance (Nov 10, 2020)

on mine i did the barb on the side, and the feed is from the bottom of the fuel tank.  so im thinking its ok to rotate it if you need
i to used lock tight on the carb - at first it tried the teflon paste sealant but it didnt hold


----------



## CFLBob (Nov 10, 2020)

werowance said:


> on mine i did the barb on the side, and the feed is from the bottom of the fuel tank. so im thinking its ok to rotate it if you need
> i to used lock tight on the carb - at first it tried the teflon paste sealant but it didnt hold



Very helpful.  I was looking at mine and thinking that spark plug was too close to where I'll be sticking my fingers.  I've been zapped enough in life, thank you.   Rotating 90 degrees like yours is a simple way around that.


----------



## CFLBob (Nov 15, 2020)

I've gotten myself into a hole I can't seem to get out of.  While waiting for my fuel line to get delivered, I thought I'd try to get rid of the offset between my gears and slide the crankshaft a little away from the side with the cylinder, piston and all.  I think it's mostly cosmetic.  

I can't pull the spring pins out of the holes they're in (and sticking out of).  I didn't drill through the crankshaft, so I can't hammer them through, and when I try to grab them with Vise-Grips and pull them out, the pliers always slip off before the pin moves.  

How do I get the spring pins out?


----------



## awake (Nov 15, 2020)

Bob, I hate to say that this does not sound good to me - the options for removing the pins will be greatly complicated by the fact that they are in the assembly - or to say it another way, access will be an issue.

One option is to try to drill them out. Spring pins are hardened, so carbide will be needed ... and carbide will be very difficult not to break unless you can do the drilling in a mill ... which brings us back to the access issue. (Even, then, the interrupted cut from the slot in the pin may cause problems.)

Another option would be to use a carbide endmill to mill it out. Again, interrupted cut is not great, but you may be able to mill just the side of the pin opposite the slot. Again, though ... access and fixturing will be the key.

One more option comes to mind; it is messy, but may be your best bet if you can't get into where you need to get with a carbide drill or endmill. You can locate the shaft opposite the pin and drill out to create a through hole. Then you can use a punch or pin driver to drive out the spring pin.

These are the ideas that occur to me ... but maybe someone else will have a better option to offer.

Well, actually, one more - I didn't mention EDM as not many home machinists have one. Also, the typical EDM immerses the part in a dielectric fluid. I don't know how compatible the commercial fluids would be for immersing an engine. I have built an EDM (which is currently in pieces awaiting an upgrade), and in that I used kerosene as the dielectric (sounds like a fire hazard waiting to happen, but seemed to work just fine) - I would think your engine would survive just fine being immersed in kerosene.


----------



## scottyp (Nov 15, 2020)

awake said:


> One more option comes to mind; it is messy, but may be your best bet if you can't get into where you need to get with a carbide drill or endmill. You can locate the shaft opposite the pin and drill out to create a through hole. Then you can use a punch or pin driver to drive out the spring pin.



I'd probably go in this direction.


----------



## CFLBob (Nov 15, 2020)

awake said:


> One option is to try to drill them out. Spring pins are hardened, so carbide will be needed ... and carbide will be very difficult not to break unless you can do the drilling in a mill ... which brings us back to the access issue. (Even, then, the interrupted cut from the slot in the pin may cause problems.)



Drilling on the mill table is conceivable, because that's how I drilled the holes they go in.  A 3/32" carbide bit might be tricky to come up with, but I've never looked.  BUT, the pin is at angle to the vertical so the other side, with the pin leaning in toward the flywheel center, has worse access.  

I don't have a good picture, but it's to fix this:






You can kind of see how the steel gear is offset from the brass gear to the right.  It's about 1/4 of the width of the teeth off.  You can see the pin, at an angle to the vertical.  

Plan B might be "live and learn."  Ignore it and do better next time.


----------



## coulsea (Nov 15, 2020)

There is a lesson there. I have built a couple of engines with a ball bearing big end on a fabricated crank using loctite and pins, my son managed to get some amazing revs out of his and the bearing disintegrated, because the holes for the pins were not drilled all the way through and were stainless steel in a mild steel web it was easier to make a new crank, this time drilling through.
if it is only cosmetic maybe its better to fix it in Webster 2.0 or maybe trim the brass gear so at least one side lines up.


----------



## Brian Rupnow (Nov 15, 2020)

Take a pair of wire cutters. Look close and you will see that there is quite a pronounced chamfer on the side of the jaws. Hold the cutters up against a grinder until that chamfer is almost gone, leaving a sharp edge. Now the wire cutters will grip the pin and pull it out. It is also a great tool for removing taps that break off leaving only a shred of tap above the surface of the material being tapped. It lets you grip the tap and gently unscrew it.


----------



## scottyp (Nov 15, 2020)

Good idea - I have actually used that method on other items needing removal. 

It reminds me of what my favorite of wire cutters look like after someone (usually an engineer or one of my kids) borrows them to cut something other that wire.  Now I keep my nice ones hidden.


----------



## CFLBob (Nov 15, 2020)

Brian Rupnow said:


> Take a pair of wire cutters. Look close and you will see that there is quite a pronounced chamfer on the side of the jaws. Hold the cutters up against a grinder until that chamfer is almost gone, leaving a sharp edge. Now the wire cutters will grip the pin and pull it out. It is also a great tool for removing taps that break off leaving only a shred of tap above the surface of the material being tapped. It lets you grip the tap and gently unscrew it.



I refer to side of the cutters you show in the top photo as the back of the pliers.  Most cutters have a chamfer on that to make an angle on the jaws for better cutting.  I can see you ground the backs to flatten it and remove the taper toward the cutting edge.  Do you flatten the cutting edge to make it more square?  It looks like it in the bottom picture, just at the end.


----------



## Brian Rupnow (Nov 15, 2020)

Regardless of what the picture looked like--I try to remove the chamfer completely so the gripping edges are almost as sharp as knife blades. This is a very slippery slope, because if you get too enthusiastic and grind beyond the "cutting edge", then you have a gap which won't grip anything.


----------



## Cogsy (Nov 16, 2020)

I was going to suggest the same tool Brian did (we know them as 'side-cutters' down here). Looking at the picture, I would have thought there was enough pin sticking out that the cutters wouldn't even need modifying. Many times I've used side-cutters to grab and manipulate heavy springs, mostly in drum brakes on old cars (which I suspect is where Brian learnt this trick as well).


----------



## CFLBob (Nov 16, 2020)

Cogsy said:


> (we know them as 'side-cutters' down here)



I grew up calling them dikes, short for diagonal cutters.  When you're building electronic stuff, they're among the most used tools.


----------



## awake (Nov 16, 2020)

CFLBob said:


> Drilling on the mill table is conceivable, because that's how I drilled the holes they go in.  A 3/32" carbide bit might be tricky to come up with, but I've never looked.  BUT, the pin is at angle to the vertical so the other side, with the pin leaning in toward the flywheel center, has worse access.
> 
> I don't have a good picture, but it's to fix this:
> 
> ...



Bob, I'd start with Brian's idea - wish I had thought of that. But if that doesn't work, keep in mind that drilling from the back side only has to create a path for a drive pin. IOW, you don't have to match the path of the spring pin exactly, and you don't need to drill the same diameter. You may be able to drill a 1/16" hole that intersects with the spring pin, and use that to drive it out. Or you may have to drill a larger hole - 1/8" or so - to expose enough of the spring pin.


----------



## John Antliff (Nov 16, 2020)

Sacrifice a pair of toe nail cutters, they don't have bevels on the cutting edges.   It will ruin them for their proper use but will allow you to grip the roll pin and with the help of a screw driver blade between the cutter and the flywheel boss enable you to lever it out.  Next time, make a through hole!


----------



## werowance (Nov 17, 2020)

bob, i may have missed this so if you said so disreuard.  but do you have a pencil butaine torch?  like the cheap ones you can use for soldering?  if so you mght be able to heat that pin which will remove the springiness (technical term)  and possibly while its hot dikes, end cutters or toe nail clipers might be able to pull it.  i know the cheap roll pins just loose all their outer compression force (spinginess) after heat and are trash once they have been hot.   aka - harbor freight roll pin kits.    

but on the other side, i dont know how heat spread may creap up into your other parts and cause problems


----------



## CFLBob (Nov 18, 2020)

werowance said:


> bob, i may have missed this so if you said so disreuard.  but do you have a pencil butaine torch?  like the cheap ones you can use for soldering?  if so you mght be able to heat that pin which will remove the springiness (technical term)  and possibly while its hot dikes, end cutters or toe nail clipers might be able to pull it.  i know the cheap roll pins just loose all their outer compression force (spinginess) after heat and are trash once they have been hot.   aka - harbor freight roll pin kits.
> 
> but on the other side, i dont know how heat spread may creap up into your other parts and cause problems



I do have a small Blazer butane torch, but I really cringe about the effects of the heat on the rest of the parts.  While I got the box of assorted pins from Amazon, I'm sure it's the fine, high-quality, Chinesium of Horrible Freight pins, so heating it will turn the pin back into whatever kind of cheese it's made from.  After it sets fire to the light coat of oil on everything.  

I have a pair of dikes I was going to grind and now I can't find them.  Likewise, I'm reluctant to sacrifice the toe nail cutters until I have a replacement, so I mostly look at it and put off deciding whether or not I want to mess with it, or be willing to attack it figuring I'm going to have to make a new crankshaft and rebuild it.


----------



## minh-thanh (Nov 20, 2020)

Hi Bob ! 
Has your problem been resolved?


----------



## CFLBob (Nov 20, 2020)

minh-thanh said:


> Hi Bob !
> Has your problem been resolved?



Hi, Minh Thanh,

No, it's not.  I have three pins I'd like to pull, one pin broke off, the second pin broke the nail clippers, and I can't get access to the third with a tool.  I still can't find the junky diagonal cutters I've been looking for but right now, it's still like it was.   

I had to order some things and now I'm building up something to hold the plastic gas tank.


----------



## minh-thanh (Nov 20, 2020)

If  keep everything the same, will it have any effect?
otherwise, no change is required
If there is an influence, you can change the other part accordingly
Not necessarily the same as the plan 100%


----------



## CFLBob (Nov 20, 2020)

minh-thanh said:


> If  keep everything the same, will it have any effect?
> otherwise, no change is required



I think the important part is no, it won't have any effect, it's just not as nice-looking as I'd like.  So I'm pretty sure I'm leaving it as is.


----------



## Longboy (Nov 21, 2020)

CFLBob said:


> I think the important part is no, it won't have any effect, it's just not as nice-looking as I'd like.  So I'm pretty sure I'm leaving it as is.


Your solution is to move the brass gear into alignment with the crankshaft gear. I understand with a press fit or Locktite  of the crank throw to the crankshaft, removal of the crank/ flywheel out of the frame is an issue. This crank throw should be set screwed to a flat on the end of the crank for ease of removal and servicing then. 






On your carb rotating in the manifold, larger diameter round stock (5/8in) bored 10mm for your Traxxas carb will give you enough wall thickness for a 6-32 set screw to lock carb in any position to the manifold.


----------



## werowance (Nov 21, 2020)

yeah,  from that point of view, it looks like you have a bit of room to move the brass cam gear over a bit.  would it interfear with the cam rocker arm to much that a little fling would be a problem?  i know that the striker pad from rocker to valve - for my engine was a bit oversized anyway so i could put a knurled edge on it.  so maybe  increasing the rocker pad if need be would give you the room to move the bass gear and cam over a tad bit.  just a tad shim.

BUT looking at it im not sure you can get the gear off without removing the flywheel which is your problem you are working on.  so if that is for sure the case,  then what abut a machined c clip brass spacer so to speak and a drop of lock tight?  slip it in and put a drop on - go eat some dinner and it will be spaced right for you.?  would that work?   take a washer to the right thickness and cut out an end so it will go over the shaft?


----------



## CFLBob (Nov 24, 2020)

I ordered points on Saturday from AutoZone, and got a call they were in.  There's something clearly wrong here and I need something else, but I'm not sure what. Has anybody built the Webster with the points and capacitor that Joe Webster called out?

My engine:





You can see the sheet metal spring hanging off to the lower right around the black SHCS, and to the lower left of the screw is the contact.

Sheet 15 of the plans seems to show something hanging off the sheet metal piece the points are backed by.   The metal spring appears attached to that. 




*Edit *after hitting "Post" instead of "Full image." 

First off, it's possible they sent the wrong set of points, or that I ordered the wrong set.  Since I'm using a CDI, there's no capacitor (condensor) there mounted to the base.  I could make a little piece of aluminum to mount to the base.  A place to attach that spring steel on top and then a way to attach to the base on the bottom. 

While, I'm here, I built a little holder and base for my fuel tank.  That's visible on the right edge of the photo.  This was a test fit that I'll take apart so I can do some finish work on the base.


----------



## Brian Rupnow (Nov 24, 2020)

Either you have the wrong point set, or your point set is incomplete. the points are #018-4126-8  A110P


----------



## scottyp (Nov 24, 2020)

Yeah, those point are clearly missing the threaded stud and nut which would hold the spring in position.  It looks like there were a couple of options for the mopars of that era, maybe a couple of different distributors were used. It may be possible to use them, but it may not be the cleanest looking.

Search "Contact Set Standard CH14VT"  on EBAY, that is what I used.


----------



## CFLBob (Nov 24, 2020)

Brian Rupnow said:


> Either you have the wrong point set, or your point set is incomplete. the points are #018-4126-8  A110P



Thanks for that part number.  There's no such thing as too much information. 

I went to AutoZone using the info that Joe has on the Webster prints. "1969 DODGE CHARGER, 383, 4BL, W/SINGLE POINT DIST"  AutoZone returns one thing, Duralast AL1023MV








						Duralast Point Set AL1023MV
					

Shop for Duralast Point Set AL1023MV with confidence at AutoZone.com. Parts are just part of what we do. Get yours online today and pick up in store.




					www.autozone.com
				




They don't have a cross reference for the 018-4126-8 number. 

Pardon if this is stream of consciousness and not very edited, but I just checked Advance Auto Parts, and they have a set of points with the threaded stud and nut.


			Advance Auto Parts  - Down for Maintenance
		

and they do cross reference those points to your number.
I'll give them a call and see what it takes to get a set.  At AutoZone I had to buy the points in advance and get them shipped over from Orlando (nearest big city).


----------



## werowance (Nov 24, 2020)

hi bob, i used the doge points myself, they worked ok for me.  here are some pics i have on my pc of my points,  im not allowed to go in my office for a few days due to covid but when i get back in ill take some better pics if you need/if it will help


----------



## werowance (Nov 24, 2020)

and the advance auto parts set looks correct.  probably doesnt have the condensor with it as its usually sold seperately


----------



## Sprocket (Nov 24, 2020)

If you are using a CDI, do you need points? Wouldn’t you use a magnet and Hall effect trigger?
Or maybe I’m misunderstanding.


----------



## CFLBob (Nov 24, 2020)

werowance said:


> and the advance auto parts set looks correct.  probably doesnt have the condensor with it as its usually sold seperately



Thanks.  Looking at your picture made me think their's look like the right points.  I'll give Advance Auto a call in the morning and see if they have them, or if I have to order for pickup on Friday or something.   



Sprocket said:


> If you are using a CDI, do you need points? Wouldn’t you use a magnet and Hall effect trigger?



I ordered the CDI from Roy Sholl and the way he explained it was the CDI replaces the coil and cap.  I could use a hall effect switch and magnet, but points work fine, too.  He said it makes the ignition cam simpler.  

The last car I worked on that had points and a coil was a 1972 Ford Pinto, back when CDI was exotic and expensive.  I sold that car in 1982 and haven't touched a manual ignition system since then, so I'm real hazy on how we made them work.


----------



## ZebDog (Nov 25, 2020)

I used a set of Lucas points and condenser £2.95 on eBay and the coil from a scrap yard as you can see in the pics the coil and condenser are mounted underneath inside the box.


----------



## CFLBob (Nov 25, 2020)

ZebDog said:


> I used a set of Lucas points and condenser £2.95 on eBay and the coil from a scrap yard as you can see in the pics the coil and condenser are mounted underneath inside the box.



I like it! 

One of the things I picked up by looking around is that if you build a lot of engines, you either duplicate the ignition system a lot of times or you build one into a box and make it as portable as possible.  It seems a lot of guys use one box between various models.  One of my thoughts behind the electronic ignition was to do that, using the CDI module (a black plastic box) instead of the coil and cap.  I need to flesh out those plans and design a little box.


----------



## coulsea (Nov 25, 2020)

I have just made an ignition box on the 3d printer, it has the batteries in the bottom section then the rcexl ignition and switch in the top and a tacho in the lid. each engine has a hall sensor so you just have to plug in the sensor and put the plug cap on and it is ready to run. some of my better engines have the ignition built in but the others just use the common one. this one is for my son so I don't have to buy a new ignition for every engine.
The hall sensors are good because they are so small and you can be creative in the way that they are mounted.


----------



## awake (Nov 25, 2020)

Here's another option - when I bought points for my Webster build, I went with the ubiquitous Ford tractor part:






						Amazon.com: Ignition Kit Ford 2000 4000 600 6000 6100 700 800 8N 900 NAA Jubilee Tractor: Industrial & Scientific
					

Buy Ignition Kit Ford 2000 4000 600 6000 6100 700 800 8N 900 NAA Jubilee Tractor: Coils - Amazon.com ✓ FREE DELIVERY possible on eligible purchases



					www.amazon.com


----------



## werowance (Nov 25, 2020)

it was posted about using points with a cdi or electronic ignition,  the answer is yes.  in this config it is nothing more than a switch or trigger just as the magnetic hall effect switch is.  cdi or electronic needs some sort of a "switch"  thing is that since you aren't flowing the high energy through the point then they don't break down nearly as bad as non cdi.  your points just become a low voltage on and off switch at this point.   which helps with the break down of points systems such as pitting due to arking and such.  long story short with most cdi all you need is a simple on / off switch happening at the right time.  just like points do.  except with cdi points usually don't arc and such coming from the condenser which isn't needed any more either.   hall effect is a wonderfull thing on my old farmall.  everytime I would leave that tractor out and it got wet I had to replace the points.  havnt had to do anything in over 10 years since replacing with a pertronix hall effect ignition.


all that said the points work just fine for the Webster and are very simple.  no adaptation needed to modify the plans for hall effect magnet switching.


----------



## Jimmyc (Nov 26, 2020)

Hi all. Just what is probably a basic question for you Webster builders. I am considering using the Minimag system same as I used on my Wyvern engine. Question is, would the Hall pick up magnet need to be fitted to the larger cam spur gear in order to pick up half engine speed? Thanks.


----------



## CFLBob (Nov 26, 2020)

Jimmyc said:


> Hi all. Just what is probably a basic question for you Webster builders. I am considering using the Minimag system same as I used on my Wyvern engine. Question is, would the Hall pick up magnet need to be fitted to the larger cam spur gear in order to pick up half engine speed? Thanks.



I think that's right.  It would go near the exhaust cam on the bigger gear.  Attached somewhere, somehow.  The exhaust cam pushes the lever that opens the exhaust valve, so that's almost a full cycle of the piston past where the spark plug needs to fire.  Maybe that means it would be opposite the top lobe of the exhaust cam.


----------



## CFLBob (Nov 26, 2020)

coulsea said:


> I have just made an ignition box on the 3d printer, it has the batteries in the bottom section then the rcexl ignition and switch in the top and a tacho in the lid. each engine has a hall sensor so you just have to plug in the sensor and put the plug cap on and it is ready to run. some of my better engines have the ignition built in but the others just use the common one. this one is for my son so I don't have to buy a new ignition for every engine.
> The hall sensors are good because they are so small and you can be creative in the way that they are mounted.



That's a very nice implementation.  I've been thinking of doing something like that, but haven't thought it through well enough.  

Do you have a small 6V Gel Cell in there, or a pack for four alkaline batteries?  Here I go assuming yours runs on 5 to 6V like the one I have.

I'm getting ready to go out of town for Thanksgiving.  I'll see things tomorrow.


----------



## vederstein (Nov 26, 2020)

This is the thread that just won't die....


----------



## coulsea (Nov 26, 2020)

Jimmyc said:


> Hi all. Just what is probably a basic question for you Webster builders. I am considering using the Minimag system same as I used on my Wyvern engine. Question is, would the Hall pick up magnet need to be fitted to the larger cam spur gear in order to pick up half engine speed? Thanks.


you can have the hall sensor on the crank, you will have a wasted spark at the top of the exhaust stroke. makes mounting a lot easier.


----------



## coulsea (Nov 26, 2020)

CFLBob said:


> Do you have a small 6V Gel Cell in there, or a pack for four alkaline batteries?  Here I go assuming yours runs on 5 to 6V like the one I have.
> 
> I'm getting ready to go out of town for Thanksgiving.  I'll see things tomorrow.


this unit runs off 6 -12v so i am using 4 AA batteries, some of the earlier rcexl units were 4.5 - 6v and use 3 AA batteries.
I have tried some cheap Chinese CDI that say they are 6v but are more reliable on 4.5v


----------



## CFLBob (Dec 1, 2020)

OK, the right points are here, and installed.  I need to get the position of the ignition cam timed right and hook up the CDI ignition.


----------



## minh-thanh (Dec 2, 2020)

Look great !


----------



## Brian Rupnow (Dec 13, 2020)

CFLBob--What's happening with this engine. I check every day and it seems to have gone dead.


----------



## CFLBob (Dec 13, 2020)

I'm expecting to try to get it to run today.  The holidays and working on my bike intervened.  My version of your "old man's walk" is I ride a road bike for an hour a few times a week.

I was going to try to test the electronic ignition a couple of days ago and I ran into something I'd never seen before.  The cam would push the points open but they wouldn't close on their own.  I took them off the support and they hardly moved in my hand.  After an hour of poking and prodding, and everything I could think of, I put drop of oil in the right side and they started to work better.  They seem to work now.  

It has been nearly 40 years since I worked on a car engine with points but I swear I don't remember EVER oiling points.  Or even hearing about oiling points.

My plan was to sit down with the forums and try to see what other people went through getting their Webster to start for the first time.


----------



## Jimmyc (Dec 13, 2020)

Are you by any chance nipping the points spring with your cap head screw?


----------



## Brian Rupnow (Dec 13, 2020)

Put a dab of grease on the white nylon rubbing block where it rubs on the points. If you don't, it will wear away in a very short time.


----------



## CFLBob (Dec 13, 2020)

Jimmyc said:


> Are you by any chance nipping the points spring with your cap head screw?



I thought that might be the case and backed the screw out.  It didn't make a difference.  



Brian Rupnow said:


> Put a dab of grease on the white nylon rubbing block where it rubs on the points. If you don't, it will wear away in a very short time.



That part I got.  The points from NAPA came with a little capsule (I mean it looks like a drug capsule) with some black grease in it.  I've applied that.  

Since I've never seen one of these Traxxas carbs, what settings do you recommend?  I backed the needle valve out (I think) by about a quarter turn.  Does the air intake go to minimum to emulate a choke?  Richer fuel, lower air?  

I verified my spark plug sparks, so I'm just going through the final steps before first attempt to fire it up.


----------



## CFLBob (Dec 13, 2020)

It doesn't run.  I suppose I would have passed out from shock if it had started up, so maybe it's good to not get a concussion on my concrete floor.    






I'm using Coleman fuel with a shot of WD40 in the bottle before I added the fuel.  

I'm using a battery powered drill/screwdriver.  It sounds better on it's faster speed, low torque setting but doesn't try to keep running.  The intake valve only makes tiny movements, it doesn't get pulled down strongly.   

There are three adjustments on the carburetor.  The big one on the "arm" with the fuel inlet, the thing I'm used to calling a throttle plate on the top, and another small screw with a spring on it, just hidden by that lever on the throttle plate.  I could use hints on how to set those.  I've backed the big one on the inlet arm out a full turn, but not more, moved the throttle plate a few times and adjusted the small screw out by quarters to a full turn out.  I have no idea if fuel/air mix is getting to the cylinder.


----------



## Brian Rupnow (Dec 13, 2020)

You can google for Traxxas carb settings. They should run without any adjustment, just as you buy them. If you have been twisting screws you have probably buggered something up. Traxxas maintains a web page about their carburetors. I have had to refer to it in the past. It is doubtful that you will see the intake valve move very much. If you have a transparent fuel line you should see the carb lifting fuel up from the tank as you crank it over.


----------



## CFLBob (Dec 13, 2020)

Thanks for the tip.  Got and printed out the instructions.


----------



## werowance (Dec 14, 2020)

on my carb,   no adjustment needed and only open abut 1/4 of the way for starting was its sweet spot for me..  i  know everyones may need a little different changes though.  the main mistake  i was making was trying to start it backwards.  i doubt you are but wanted to point it out  just  incase.


----------



## CFLBob (Dec 14, 2020)

Good point, and thanks.  I'm rotating the flywheel counterclockwise when viewed from the side with the points, like this. 




I'm using a battery powered drill and I find that it sounds more like it's trying to start if I run it fast.  I don't know how many RPMs either one is with my drill, but it has a switch that moves a gear so that it's either slower with more torque or faster with less.  

This morning I woke up with a voice in my head saying, "double check your *&&$ing timing!"


----------



## minh-thanh (Dec 14, 2020)

Hi CFLBob !
Make sure the atmospheric valve is moved "free ".
Put some oil w40 in the valve guide
With me, the atmospheric valve spring is only job :  keeping the valve at the closed position with 1 force :  very little force


----------



## awake (Dec 14, 2020)

Bob, some thoughts & comments from my experience starting my Webster:

1) The obvious: do you have good compression? Does the intake valve "burp" when you turn it through the intake portion of the cycle?

2) Timing is a good thought - both exhaust and ignition. When I first attempted to start my Webster, I had no luck. I tried moving the exhaust cam by one gear tooth, and it started right up.

3) I have never succeeded in starting my Webster on the slow speed of the drill - which seems very odd since I can hand start it so long as the mixture is right. (It does take several attempts to hand start it, unless it is warmed up and the settings are dialed in - then it starts with a single spin.) But back to the drill - for some reason, when starting with the drill, it only works on high speed.

4) I'm not sure which screw you were talking about having 1 full turn, but if that is the mixture needle, it may be way too rich. That said, the nice thing about starting with a drill is that you can keep spinning it while adjusting the needle until it begins to catch. You can also use your finger to block the air intake on the carb to choke it - especially after mine has sat for a week or more, this helps to get it going.

5) You might try straight Coleman gas, without the WD40, at least until you get it running. I find that my Webster is harder to start and does not run as smoothly when I run mixed gas + WD40 - even what seems like a tiny amount of WD40. (I do run the occasional tank of mixed through just to be sure everything gets a bit of lube - maybe every 6th tank or so.)

6) What size throat is the Traxxas carburetor? If it is too big, it will be very hard to start. As I recall, the throat on my carb is .140", and that may be a big on the large size.


----------



## werowance (Dec 14, 2020)

Bob, are you getting pops,  burnt oily residue coming from the cylinder etc?  I will say with my traxxas carb set at 1/4 throttle it does take a good 20 seconds of spinning it over before I can remove the drill off of it (I'm using the rubber disk on the fly wheel).  I do get some noise from it but it wont take off on its on until about 20 seconds.   alsoi use regular 5w30 oil on the cylinder oiler and on top of the valves etc.  the 30 w oil will push out black crud when its doing some firing,  slings it all down the base plate.

on the intake valve spring,  mine was way to strong at first as well.  if I remember right I finally ended up using the spring off a set of brushes from an old broken angle grinder.  it was the right size and weak.  just enough to keep the valve closed.  but in your description the valve just barely moves.  so does mine even when running.


----------



## CFLBob (Dec 14, 2020)

werowance said:


> Bob, are you getting pops,  burnt oily residue coming from the cylinder etc?  I will say with my traxxas carb set at 1/4 throttle it does take a good 20 seconds of spinning it over before I can remove the drill off of it (I'm using the rubber disk on the fly wheel).  I do get some noise from it but it wont take off on its on until about 20 seconds.   alsoi use regular 5w30 oil on the cylinder oiler and on top of the valves etc.  the 30 w oil will push out black crud when its doing some firing,  slings it all down the base plate.
> 
> on the intake valve spring,  mine was way to strong at first as well.  if I remember right I finally ended up using the spring off a set of brushes from an old broken angle grinder.  it was the right size and weak.  just enough to keep the valve closed.  but in your description the valve just barely moves.  so does mine even when running.



I'm getting oil spraying everywhere: baseplate, around the front of the cylinder, top of the head, sprayed across the work bench, on my pants, me, everything.  I'm just not sure about being burnt.  I get oil residue in the exhaust pipe.  

A strange thing I'm seeing is what looks like the fuel oozing between the three segments of the valve stack.  It's visible in the test video where you can see the fuel bubbling under the right hand screw at around the 50 second mark (it's not a specific time).  Maybe my brown paper bag gaskets suck and I should use some of the gasket material I had to buy to make the head gasket.



The spark plug fired when lying next to the cylinder, before I started all this, so I appear to have spark and fuel.  In the video, you can hear a puffing or snorting sound as I move the flywheel by hand.  

What am I missing?  

Before I tried again today, I used the instructions from Traxxas to reset the screws I messed with.  It's pretty straightforward.  I also double checked the ignition timing.  It might be within a few degrees of TDC, and Joe Webster says "about 15 degrees before TDC."  It's close to that.  

BTW, I took that rubber disk trick when you mentioned it and am using one here.  You'll see it.


----------



## Brian Rupnow (Dec 14, 2020)

Your gaskets are leaking on the intake stack, and the engine isn't firing at all. You should have a transparent fuel line so that you can actually see the fuel being sucked up by the carburetor, and your intake valve spring is probably too strong.


----------



## stevehuckss396 (Dec 14, 2020)

I agree with Rupnow. I don't see the intake valve opening. Don't see any movement at all.


----------



## coulsea (Dec 14, 2020)

My battery drill will not start a new engine, just not fast enough (1200 rpm should work), if you have leaks in the valve block, valves, rings and head it all adds up to not enough compression to fire. intake valves don't move much, a finger over the intake will tell you if it is sucking at all, same with exhaust blowing. a few drops of oil down the bore may help (not WD40). everything the others said is correct as well.


----------



## CFLBob (Dec 14, 2020)

Brian Rupnow said:


> Your gaskets are leaking on the intake stack, and the engine isn't firing at all. You should have a transparent fuel line so that you can actually see the fuel being sucked up by the carburetor, and your intake valve spring is probably too strong.



#1 is easy; I have plenty left over.  
#2 is puzzling.  As I said, the spark plug was firing out of the cylinder head, just lying on the base of the engine.  You can see the LED flashing at the far end of the S/S CDI box, which was flashing every time the points closed and triggered the spark.  All I can do is pull the plug again and see what it looks like outside the engine.  
#3 that fuel line is transparent and I can see into it.  It appears full of fuel.  Seems it would have to be full.  
#4 the valve spring is made with .015 wire instead of the .013 called out because I didn't have any .013.  



coulsea said:


> My battery drill will not start a new engine, just not fast enough (1200 rpm should work),


My battery drill has two modes which give lower and higher RPM.  I'm using the high speed one.  The manual says 1,600 RPM with no load, which doesn't say much.  I also have two AC powered hand drills.  I can look into which is faster.   

Question:  Webster says (page 20), " Rotating the flywheel counter-clockwise (viewed from the flywheel side) should produce a "snorting" sound through the carburetor as the intake valve lifts.  Since the flywheel is very visible from any side, I want to know if I'm correct in rotating it counterclockwise in the view in the video.  I would call that the ignition points side.  (I would call the opposite side the cylinder and combustion chamber side).  

I thought that sound I got out of the engine on every rotation of the flywheel (in the first 20 seconds of the video) was the snort I should be listening for.  It's very audible although I had to turn up the volume.  If that's indicating the intake valve is working, I'll work on other things first.


----------



## Brian Rupnow (Dec 14, 2020)

.015 diameter spring wire should be fine for an air actuated intake valve. Turn the engine by hand, in the direction you think it should be turning, with the sparkplug laying out on the block. You should see an actual spark at the plug just before the piston reaches top dead center. The cam operated exhaust valve should begin to open about 3/4 of the way thru the power stroke (piston going towards bottom dead center).  Exhaust valve should be fully closed at or just before the piston reaches top dead center on the exhaust stroke.  If you want to check for compression leaks, squirt a little undiluted dish-washing detergent around the places you think may be leaking and turn the engine over with your drill while watching for bubbles. (with sparkplug in). Check for leaks around the sparkplug.


----------



## Longboy (Dec 14, 2020)

Check your valve closure for leaks using a compressor blow off nozzle (at single digit PSI) thru the spark plug hole. Your spark timing should be at TDC. One turn open on the Traxxas carb. Throttle open near a quarter or less. Your ex. valve should be closed at TDC. If you are getting fuel mix dripping outta the cylinder on priming, the carb is feeding the combustion chamber. If not, the in. valve is not moving. I see the fuel weepage on the valve block. If there's fuel there can be air leaking too. I have used painters tape  and Scotch tape for a gasket. Make sure the batteries are charged up. They get down below 1 point zero something, its all over at the spark plug.  You can't start a model engine with a cordless drill on the slow setting.  What really bothers me is:  I'm looking at your video and going frame to frame to where the ex. valve closed. Your con rod looks somewhere near the 12 O'clock high position then. That is way beyond where it needs to be closed and kinda confirmed a similar rod angle with the ex. valve opening. My best bet then is intake valve not opening because the exhaust valve is open way after TDC for the intake stroke.


----------



## coulsea (Dec 15, 2020)

Looking back at your video I notice that you don't touch the carby. I have tried those carbs and found that they don't function like they should because they are designed for a different fuel and a different rev range. Not saying it's no good but it may only work through part of the throttle range, so start turning it over with the throttle closed and slowly open open it up. if that doesn't work I would try 3/4 throttle with the mixture screw in and then slowly turn it out while cranking it over. You can use the drill chucked directly onto the crank to make it easier to use one hand on the carb, just until you start getting some bangs. Each engine is unique and you have to learn what it needs, the old british single motor bikes had their own character and people would say "yes you can ride it if you can start it".


----------



## Steamchick (Dec 15, 2020)

Brian, I am Glad someone with experience says the intake valve spring should be OK... I thought the wire, although only 2 thou thicker, would be more than twice as stiff as the planned size, needing twice as many turns to make it as soft as designed. (Stiffness goes up as the cube of diameter!).  But I haven't made a working infernal combustion engine myself.
Bob, I don't  know your ignition box of tricks. My experience is only with points and coil systems that fir the coil when contacts BREAK. The contact closed time charges the system (maybe why the LED illuminates?), the break triggers the coil to make the spark. Therefore a system timed on contacts "making" is new to me. Just check your instructions? - Can you see the piston position when the spark occurs? (PLUG outside engine, looking through the plug hole? Or by the crank position, or looking up the cylinder at the bottom of the piston?).
Personally, I suspect a lack of air, either because the valve spring is too strong so too little intake, or carburation is too rich. But wrong ignition timing and it will never run either.
But good comments from everyone else (with more expertise), so maybe I am wrong?
Good fun making it run!
K2
K2
K2


----------



## scottyp (Dec 15, 2020)

Plenty of good info for you to digest.  Let me add to that.  This engine is pretty forgiving, but we need to have things at least close to the correct timings.  We need Suck-Squeeze-Bang-Blow, fuel and spark do help.

This is my approach and other's mileage may vary but here goes.

Let's start with Squeeze.  As you turn the flywheel by hand in the running direction (spark plug installed), on the compression stroke you should definitely feel the compression of the air and if there are little to no leaks, the piston should "spring" back against you if you let go of the flywheel. If there are leaks, they will show up here.  As Brian mentioned, a little soapy water on the valve block (gasket issues), also listen for air leaking out the carb and/or out the exhaust (valves not sealing).  As you compress the air, tap the intake valve and you should get a good little pop out through the carb.  Since you will most likely have the valve block off at some point, check your compression by plugging the intake port on the engine frame with your finger, you should have good piston spring back.  In either case, a SMALL, SLOW leak MAY not impede starting, but let's go for a negligible leak.  Make sure you are adding a bit of oil (not the WD40) to the piston to help lube and seal things.

OK, Bang. Once you have the above compression good, turn the flywheel to TDC on compression and release the air by hitting the intake valve.  Since we don't have spark going right now, no bang here, but as you now continue turning the flywheel the piston should draw in and the intake valve should give you that little burp people are talking about.

OK, Blow.  Holding you finger over the exhaust pipe and continue turning the flywheel.  As the piston goes back into the cylinder you should feel the air being pushed out by the piston and you should be able to feel that resistance in the flywheel.  Watch and listen for leaks...

Now, Suck.  As you continue turning the flywheel, you should get another intake burp (this time, the real intake stroke). And if you hold your finger over the carb intake, you should feel that suction.

Once you like things above, make sure you have spark at the correct time as Brian mentioned.

Add fuel, close the mixture needle, and make sure the throttle barrel is wide open. Then choke the carb with your finger and turn the flywheel by hand on the intake stoke and no fuel should be getting sucked up the fuel line.  Repeat this and open the needle 1/4 turn at a time until you see fuel getting drawn up into the carb.  Now add a couple of extra intake stroke "primes" to make sure there is fuel in the cylinder and we should be ready to add spark.

Set the throttle to ~ 1/4 open, connect your ignition and give it a little spin and it should fire.  It may not keep running and you will probably have to adjust the mixture and throttle setting to keep it running.

Not directly related to this specific thread but, my opinion, experience and technique is that IF an engine is PRIMED properly before trying to run it, all it should take to get it to at least fire is a flip or two past compression. If I find myself cranking and cranking, something is wrong.  Your mileage may vary...


----------



## CFLBob (Dec 15, 2020)

I can't thank you all enough, and if I had to single out one reply it's @scottyp's detailed step by step.  It will take some time to go through, but I'll update things if anything noteworthy shows up, one big thing, I'll be back sooner, but will update you all.


----------



## wburnett2922 (Dec 15, 2020)

your engine is way to tight to run engine must be free also there can be no leaks as not only will compression not be there also will change mixture. take out spark plug fill cly with oil put plug back in turn engine by hand up against compression see where leaks are fix them a little extra oil in cly at start up will improve compression  any questions contact me


----------



## CFLBob (Dec 15, 2020)

wburnett2922 said:


> your engine is way to tight to run engine must be free also there can be no leaks as not only will compression not be there also will change mixture. take out spark plug fill cly with oil put plug back in turn engine by hand up against compression see where leaks are fix them a little extra oil in cly at start up will improve compression  any questions contact me



Interesting.  I thought the engine was too loose.  When I pull the piston back in the cylinder, I don't get any resistance like @scottyp said to check for.  With the carb fuel line disconnected, I do get a healthy puff out of the open end of the carburetor when I spin the flywheel by hand.  I take that as a good sign.  

I stepped back to take a "first things first" and replaced the gaskets in the valve block.  While the valve block was off, I fixed something that had been an issue.  The cylinder head is held to the base with three screws, one from the under side, two on the side frame.  Those screws would get loose under vibration, so I tightened them and used some of that easy to break blue LocTite.  I also pulled the spark plug and verified it was still sparking.  

I'm letting that cure overnight before I shake it up more.  

@Steamchick  and anyone else with the question about the way the points are firing - the instructions that come with the CNCengines ignition say the points will work either normally open (Kettering System) or normally closed.  Watching the points and the red LED, I think the points are actually firing when the points reopen, not when they close.  The amount of time they're closed is very small.  



Longboy said:


> What really bothers me is: I'm looking at your video and going frame to frame to where the ex. valve closed. Your con rod looks somewhere near the 12 O'clock high position then.



On the rocker arm, there's a 4-40 screw that pushes on the exhaust valve.  That had also gotten loose and made it worse.  I just put that back in position with a drop of blue LocTite on it.   Back when I was first assembling the engine, I made a little drawing to help me line things up like on p.21 of the plans, since I'm using a different crankshaft throw than the straight one Webster used.  He says the angle between the piston conn rod center and the center axis of the flywheel should be 15 degrees.  This is how my sector of a circle should look:






I rechecked that with my angle gauge and instead of being 8 degrees to the horizontal, it was 9.  That means in stead of 15 degrees joining those two axes, it's 14.


----------



## minh-thanh (Dec 15, 2020)

*CFLBob*

In your video I seem to see the engine looks like it has no compression or very little compression ,Or am I wrong !?
my engine :


----------



## coulsea (Dec 15, 2020)

CFLBob said:


> I do get a healthy puff out of the open end of the carburetor when I spin the flywheel by hand. I take that as a good sign


The carb should suck not blow.
valve timing being out by 1 degree is insignificant. as long as the exhaust valve closes at or just before TDC in order to get the full intake stroke.


----------



## johwen (Dec 16, 2020)

Question does your spark plug have a spark under compression try closing the spark gap  to say .015 gap and try again. To have combustion you only need compression fuel and spark and if timing is right it has to run.


----------



## johwen (Dec 16, 2020)

Looking at your attempt to start by hand there appears to be no or very little compression from the video and on your attempt to start with the drill it is obvious that the compression is low. take the plug out and put your finger over the hole and check compression. if low check the exhaust valve for leaks does it have clearance from the tappet rod when on the back of the cam


----------



## CFLBob (Dec 16, 2020)

minh-thanh said:


> *CFLBob*
> 
> In your video I seem to see the engine looks like it has no compression or very little compression ,Or am I wrong !?
> my engine :




No, I think you're right and that's my big concern.  When I first put this together, it was much harder to crank that flywheel by hand.  I ran it with my electric drill driving the motor for 45 minutes or an hour and it got very loose.  That's what I'm trying to investigate right now. 

My Duclos flame eater makes a very noticeable snorting sound when I turn the flywheel.  This one makes less noise, but yours seems like it bounces back from the compressed air.  I think mine should be doing that.  I want to try some of the tests people have suggested and see if I can tell more about the compression.


----------



## CFLBob (Dec 16, 2020)

johwen said:


> Question does your spark plug have a spark under compression try closing the spark gap to say .015 gap and try again.



It sparks very well with the plug out of the cylinder and picking up ground from the base plate.  

I'm going after the compression questions today.


----------



## minh-thanh (Dec 16, 2020)

*CFLBob*
With every engine I've done, If the compression is good then the other adjustments don't seem that difficult
I usually test compression like this: when I pull the piston back to the BDC , when I release the flywheel ( without cylinder head , I sealed the cylinder  by hand )
1 / With piston and clean cylinder: piston will go up TDC about 1/2.
2 / piston and cylinder with a little oil w40: piston will go to TDC, or at least near TDC
    That compression is good enough with me. ( If the valve is airtight )
Springs of atmospheric valve  :


----------



## Brian Rupnow (Dec 16, 2020)

If everything is right, then when you are turning the engine with your drill, you will definitely feel the engine "kick" when it fires. I know that when you are actually turning the motor over there is a lot happening and a lot of noise. You will however feel the kick. My best bet is that your valves aren't sealing properly.---I had a terrible problem with that when I built my Webster. even if the valves are leaking a bit, as soon as the engine starts to run, the valves will seat themselves under pressure and provide an air tight seal.


----------



## werowance (Dec 16, 2020)

on my Webster,  I do not feel the kick with the drill and rubber disk,  but I just take it off and it keeps going.  on the valve blocks,  mine seeps just a very minute amount between them,  still runs.  I surface plate sanded each surface and did not use a gasket.  on the head to cylinder I used red high temp silicone to seal it.  I know silicone and gas do not mix but it worked.  (I don't think I needed it but have not pulled the head to remove the silicone since I got it running).  

if you put your finger of the carb air intake and rotate the engine by hand,  will it suck enough gas into the engine to flood it?  if so id say you are good on suction and intake spring.  if not then spring or valve timing is likely issue.  I believe my engine would run even without the rings.


----------



## Longboy (Dec 16, 2020)

Let's get back to your ex. valve timing. Looking at your video Bob, I see at 4,8 and 17 seconds the ex. valve just closed and the con rod looks high on the crank web, too many degrees after TDC. You have very little draw left on the in. valve and that's why nobody sees it moving and also unnoticeable compression. Wrong valve timing explains these symptoms so a possibility in your Webster. Is your ex. valve closing at or near TDC ? If it is then the cam timing is fine and my breakdown of the video by the second wasn't enough for these conclusions.


----------



## werowance (Dec 16, 2020)

could it be that valve timing vs ignition timing was done with one timing done looking with the engine turning in one direction and the other timing was done with the engine rotating in the other direction.  sort of like doing valve timing by looking at the wrong side of the engine or ignition done when looking at the wrong side of the engine?

maybe these photos will help - I'm back in my office today so can take them.

crank position when the points cam has allowed the points to make full contact - photo of the crank side as well as the points cam side to show what position the crank should be in when the points make full contact


----------



## CFLBob (Dec 16, 2020)

I was just going to go play with trying to find leaks, but this has gotten important.  

Werowance - these pictures are very valuable.  Here's mine when the points should fire.  Well, within "a couple of" degrees of firing.  (Note my picture is tilted - look at the bench in the background. )  I think it looks quite a lot like yours.  






and the points






That looks a little early, but close.  

The Exhaust Cam setting instructions on the last page say to set it 15 degrees before Bottom Dead Center and that's what that little CAD drawing I put up showed.  This is the engine.


----------



## scottyp (Dec 16, 2020)

That seems reasonable...as long as your bottom pic shows the exhaust cam just starting to open AND that this pic is taken at the END of the POWER stroke (in other words, about a half of a turn of the flywheel after ignition TDC. That part is important.).

IF that is the case, I would pull your valve block off and check the compression by holding your finger over the hole in the side of the engine frame.


----------



## CFLBob (Dec 16, 2020)

scottyp said:


> That seems reasonable...as long as your bottom pic shows the exhaust cam just starting to open AND that this pic is taken at the END of the POWER stroke (in other words, about a half of a turn of the flywheel after ignition TDC. That part is important.).



That picture is supposed to match this one from the plans:




15 degrees before bottom dead center the stem of the exhaust valve just starts to lift.



scottyp said:


> IF that is the case, I would pull your valve block off and check the compression by holding your finger over the hole in the side of the engine frame.



When I do that I get good compression.  It makes a good squeaking sound as the air pushes my thumb out of the way and noticeably quite a bit harder to move the flywheel.  So it's my valve assembly that's leaking.


----------



## Brian Rupnow (Dec 16, 2020)

You are now entering the "Twilight Zone".---Leaking valves----This is the part that separates the men from the boys Bob.  I almost suffered from a Conniption fit with my first two i.c. engines, the Webster and the Kerzel Hit and miss engine because of leaking valves.


----------



## CFLBob (Dec 16, 2020)

Brian Rupnow said:


> You are now entering the "Twilight Zone".---Leaking valves----This is the part that separates the men from the boys Bob.  I almost suffered from a Conniption fit with my first two i.c. engines, the Webster and the Kerzel Hit and miss engine because of leaking valves.



Does it matter that I get a squeak on the compression stroke, bottom to top dead center, but not when piston is going from top to bottom?  

But I have your distilled wisdom that I worked by - posted here a few years ago.  So my first guess will be to lap them against the valve guides again, after some disassembly.  Before I start over and make the entire assembly over - valve guides, valves, and the three aluminum pieces.


----------



## Brian Rupnow (Dec 16, 2020)

Nah, the squeak is caused by compressed air escaping around your thumb.  When the piston is going the other way it sucks your thumb into the hole, plugs it, and pulls air in around the leaks.


----------



## werowance (Dec 16, 2020)

probably not the case, but your points cam - the flat doesnt seem as cut down as much as mine?  and my points which my pic doesnt represent it but mine seem to be touching more flatly or symetricly or some other way of saying the contacts are flatly and fully engaged and the cam isnt influincing them in the least when its on the flat.  that said i probably cut the flat further than i should have.  

i have another question and im sure it was already addressed by others in this thread,  but im going to ask anyway.  i have no experience with the electronic ignition box you are using (ive only dealt with pertronix on tractors).  does it still require a condensor or capacitor?  or is it built into the kit?


----------



## werowance (Dec 16, 2020)

bob,  it also just occured to me,  i have a webex account at work and a web cam that i can bring home on the weekend or after work.  if it would help i can do a webex and let you study my engine and move it arround and zoom in on anything you want to see.  or at least as much as the rinky dink web cam can do.   if you are intersted let me know and ill try to bring all that home tommorow.  including the engine.


----------



## CFLBob (Dec 16, 2020)

werowance said:


> probably not the case, but your points cam - the flat doesnt seem as cut down as much as mine?  and my points which my pic doesnt represent it but mine seem to be touching more flatly or symetricly or some other way of saying the contacts are flatly and fully engaged and the cam isnt influincing them in the least when its on the flat.  that said i probably cut the flat further than i should have.
> 
> i have another question and im sure it was already addressed by others in this thread,  but im going to ask anyway.  i have no experience with the electronic ignition box you are using (ive only dealt with pertronix on tractors).  does it still require a condensor or capacitor?  or is it built into the kit?



The capacitor is built into the kit.  You can use points or a hall sensor and even a switch.  I think I went with points because it was cheaper and seemed easier.  

Roy Scholl who runs the company is closing down options to retire, and they might go away.  They included a little slip of paper that they're looking for someone to buy the business.  Roy's CDI Ignition Systems 

I think my points (from NAPA) are defective.  They work for a while and then it's like there's no spring in there.  They won't snap closed.  I've never seen, never even heard of such a thing.  It was a PITA to get them, this is the second set I bought, and I'm pretty annoyed with them.


----------



## CFLBob (Dec 16, 2020)

werowance said:


> bob,  it also just occured to me,  i have a webex account at work and a web cam that i can bring home on the weekend or after work.  if it would help i can do a webex and let you study my engine and move it arround and zoom in on anything you want to see.  or at least as much as the rinky dink web cam can do.   if you are intersted let me know and ill try to bring all that home tommorow.  including the engine.



Thanks for the great offer.  I feel like it's probably not completely desperate yet.  Maybe I'm too optimistic but I'm going to go after the problem with valves not sealing.  Hopefully I won't have to remake the top and bottom pieces and just spinning them with some abrasive will seat them better and fix things.  

Of course I may have a different opinion in a few more days.


----------



## werowance (Dec 16, 2020)

Roy helped me with some ignition parts and also included the retirement slip.  i envy anyone who can retire happily and look forward to when i can as well.  just wish i could do it sooner than later.  he was very nice to help me with caps and points contact tips etc

now next i will say that i appolgize for blowing up your build with so many replies but it just occured to me that points normmaly fire the coil when they disengage and break the flow of current (counter intuitive if you dont understand it - which is me most of the time)   so since points normally are timed to disengage to fire and i think that pertronix (i may be wrong) fire when "engaged" then could the points cam be 180 out on the electronic igintion?  i bet Roy could answer it in a heart beat.  

ill try to stop bugging you with all the suggestions.  im just as anxious as i bet you are to see it run is all.


----------



## johwen (Dec 17, 2020)

When you spin it over with your electric drill and then take out the spark plug is it wet? should be. If not your not getting fuel into the engine this says valves. timing, fuel/carb possibly the problem. If you have a ball valve in the inlet of the fuel line maybe the ball is to heavy for a weak suction to lift it from its seat. If the plug is wet I would be looking at the ignition The spark should be blue and if not change your condenser, Check also that there are no High tension leaks under compression. Tick of each one of the following one at a time and stay with each until you are sure before moving fore ward
1. compression/valve seating
2. timing of valves affects above compression
3. fuel supply can you flood the carb by choking it.
4. spark timing at or just be before TDC compression stroke
5 quality of the spark under compression.
My suggestion in that order don't move on from each until you are satisfied each is up to scratch.


----------



## Brian Rupnow (Dec 17, 2020)

On the issues of the points sticking.-The hole which takes the #10 bolt is marginally undersize. Run an electric drill 3/16" diameter thru it. That should fix the points sticking issue


----------



## CFLBob (Dec 17, 2020)

werowance said:


> now next i will say that i appolgize for blowing up your build with so many replies



No need to apologize at all!  I appreciate all the suggestions.  I have to notice that some of the tips seem to be opposites of each other, but that's fine, too.

Roy seems to say that the CDI ignition will work with either the points opening or closing to set the spark.  I remember he told me the ignition cam should have rounded shoulders and but didn't really talk about what kind of radius makes them rounded.  I rounded mine over a little (barely visible in the pictures).  I've watched the points firing with the spark plug lying next to the engine and looked closely at my points.  I think I've seen them cause a spark both closing and opening.

As for retirement, I'm coming up on being retired five years.  Tomorrow is my five year anniversary of my last day at work.  I recommend it to everyone.


----------



## CFLBob (Dec 18, 2020)

Yesterday, I removed the valve block assembly and while I was experimenting with adding a gasket between that block and the engine, I noticed something funny.  I had disconnected the fuel line and stood the tank up so that the tubes were sticking upward out of the top.  I noticed that the metal piece that came on the fuel line was no longer in the fuel line, but just lying on the bottom.  

I didn't round up a glass bottle to pour the Coleman fuel into until a little while ago, and when I went to take off the top to pour out the fuel, found the plastics inside the bottle had come apart.  Badly.   







That black plastic thing, now in two pieces was used to seal the bottle by tightening that Phillips screw in the lid.  That's not sealing again.  The light blue fuel line on the brass tube and the much larger diameter tube underneath and behind it were the same piece when I got it.  That tubing swelled in size until the metal piece fell off.  I suppose if I left it lying on its side much longer, it would have started leaking.

Obviously these plastics aren't compatible with the Coleman fuel!  

This was a model aircraft tank from Tower Hobbies, and I got it mostly to save the work of making a gas tank from parts I don't have, figuring it's hard to beat the $5 tank with some extra fuel line.  

I need a replacement but don't know where to turn.  I guess RC model engine supplies are out.  Can anyone point me to a source?  Any ideas?  Is this repairable somehow?


----------



## Brian Rupnow (Dec 18, 2020)

#1--No, you can't repair it. #2--why are there 2 lines coming out of the black rubber plug? There should only be one line running up to the carburetor and an air vent to let air into the tank to keep the tank from vacuum locking as the fuel level goes down.


----------



## CFLBob (Dec 18, 2020)

Brian Rupnow said:


> ... #2--why are there 2 lines coming out of the black rubber plug? ...



The line with the short piece of tubing on it is the air vent into the tank.  The dark blue tubing is the fuel output line.


----------



## Longboy (Dec 18, 2020)

I find that cloudy looking silicon fuel lines swell in Coleman. The weed wacker/lawn mower red vinyl fuel lines are very stiff. Clear vinyl tubing works well and can bend to tight radius. You can order some Delrin round stock for the cap if your fuel bottle is up right or cap the ends of a tube with aluminum round stock epoxied in place and make a filler neck and line feed outlet for a horizontal tank. Clear PVC tubing looks cool for a fuel tank too! Just walking thru a grocery/ drug store looking at containers with screw or snap lids might give you ready made solutions also.


----------



## Ghosty (Dec 18, 2020)

The bung with the fuel lines is for "GLOW" fuel, you need the bung for "PETROL"(gas) and the problem will be fixed. Both Sullivan and Dubro make the gas bungs. Dubro Cat No. 400, Gas Conversion Stopper, also you should use Tygon fuel tube(yellow)
.

Cheers
Andrew


----------



## CFLBob (Dec 18, 2020)

Ghosty said:


> The bung with the fuel lines is for "GLOW" fuel, you need the bung for "PETROL"(gas) and the problem will be fixed. Both Sullivan and Dubro make the gas bungs. Dubro Cat No. 400, Gas Conversion Stopper, also you should use Tygon fuel tube(yellow)



Thanks, Andrew!  

The same hobby store chain I bought the other from had these.  Checking to be sure they'll fit.


----------



## Ghosty (Dec 18, 2020)

Yep, they fit, I use them in my boats, the latest one, custom step up counter rotating gear box and dog drive.



Cheers
Andrew


----------



## CFLBob (Dec 18, 2020)

Well, I was thinking of the fuel tank I have and if the stopper will fit.  It's just about 17.5mm across and I haven't found dimensions for the #400 stopper.

The hobby store online (Tower Hobbies, if you know) has the Tygon tubing but 5/32 inch.  That's 0.156 inch, 3.96mm and the tubing that fits well on the carburetor is 2.5mm, .098"  That doesn't sound like it's going to work.

Meant to say that's a wicked fast looking boat!


----------



## johwen (Dec 19, 2020)

With Hit and Miss engines you generally need a one way valve in the fuel line to prevent drain back of the fuel on Miss cycles particularly if the fuel tank has any depth and lower speed other wise the engine may stop. johwen


----------



## CFLBob (Dec 19, 2020)

johwen said:


> With Hit and Miss engines you generally need a one way valve in the fuel line to prevent drain back of the fuel on Miss cycles particularly if the fuel tank has any depth and lower speed other wise the engine may stop. johwen



This engine has nothing like that.  I built my holder for the tank with the idea that mounting the tank too high was worse than too low because the fuel would run freely into it and flood the engine, so I might need to put some shims under it to ensure fuel flow.  

As an update to my previous remarks, I found that Dubro says the gas stopper will fit anything from their 2 oz to their 50 oz tanks.  Mine is 4.  The tubing that Tower Hobbies had was 5/32 ID, but Dubro does make 3/32 ID, like that darker blue tubing in the picture (and fits the Traxxas carburetor well).  

Both of those are on order but from RC hobby shops on eBay.  Given the Christmas rush in shipping aren't like to be here until Christmas or later.


----------



## awake (Dec 19, 2020)

In terms of the gas line, I used some from the auto parts store, as best I recall - I think it was made for a weed whacker.


----------



## CFLBob (Dec 23, 2020)

My fuel stopper arrived today - the email advising it shipped said it should be here tomorrow through next Monday.  My Tygon fuel line says next Tuesday through next Thursday.  It wouldn't offend me by being here sooner.  

What I've been up to is examining the valve assembly to see what I can do about making it work better.  

I tried something I'd never thought to try before.  I disassembled the valve stack and held the intake side with its valve up to my mouth and did my best to suck on the part without interfering with motion (like getting a lip in the way).  The valve wouldn't open.  I could open the valve with my fingertip and then the air flow was enormous, but if the valve was closed I couldn't open it.  The valve slides easily by light fingertip pressure but I sure couldn't move it by suction.

When I made the parts, I dismissed something in the specs as being nice but not necessary.  What I ignored was that the top of the part had a 5 degree (included angle) taper on it.  I now think that was wrong to dismiss.  When I looked at mine, every turn on the spring was motionless except for the one or two turns beyond the end of the valve guide.  In watching other guys' videos on YouTube the spring moved more and the valve opened a lot more than I ever saw mine open.

I thought I should put that taper on the guide, and it seemed the only way to do that would be to put in the 4-jaw chuck on the Sherline lathe.  That is, the only way besides pushing the guide out of the aluminum block and running the risk of ruining it.  There was an immediate problem: I had bonded the carburetor adapter into this piece with LocTite 680.  I tried fitting it into the 4-jaw without removing that adapter, and it could be done, but the adapter was too thin and collapsed.  So I pulled the adapter out, zeroed the valve guide on the 4-jaw and put the taper on it with the Sherline compound.  






The spring now looks much better on the valve guide.   

Making another adapter for the Traxxas carb shouldn't take long, so I want to do everything I can do to the valve assembly to ensure that it will open.  I think if the problem was that the valves weren't lapped well the problem wouldn't be that they wouldn't open, it would be that they never sealed right.  They seem sealed too well.  

I'd appreciate suggestions on what to look for in these simple parts.  The valve guide is reamed to .094.  I don't have a .001" oversized reamer, but I could drill it with a #41 bit, which is .002 oversized - at best.


----------



## Brian Rupnow (Dec 23, 2020)

Bob---that is known as the "Blow yer guts out" test.---Brian


----------



## minh-thanh (Dec 23, 2020)

*CFLBob !*
With a valve and a valve seat is airtight, the valve will open automatically when there is suction force in the cylinder (spring is suitable, of course).
my engine's valve guide and valve body were very loose but I  believe the engine is still run


----------



## CFLBob (Dec 24, 2020)

Brian Rupnow said:


> Bob---that is known as the "Blow yer guts out" test.---Brian



Brian, I assume when I suck on the assembly, the valve should open.  The valve is an easy sliding fit in the valve guide, so I don't really see any sense in drilling the hole bigger.  Is there a way to test this and get useful numbers?


----------



## awake (Dec 24, 2020)

Bob, is it still not opening with the revised valve cage? It shouldn't take much "suck" to get that valve to move. If it feels like it moves easily, I wouldn't drill the guide larger; I'd think about a lighter spring. But take my thoughts with a grain of salt - I have only a smidgeon of experience, where Brian and others are the masters!


----------



## Brian Rupnow (Dec 24, 2020)

Bob, I have used the old "blow yer guts out" method to check a lot of engine related things. Another way to check for leaking valves or rings is to sacrifice a sparkplug, knock all the ceramic out of it and solder a stub of 0.175" diameter tube to the part that sticks outside the cylinder where the porcelain used to. Screw the plug into the cylinder head and torque it down to spec. Then rotate the engine to top dead center, on the intake stroke so that in theory both valves should be completely closed. Now connect your air-line to the stub of 0.170" diameter material welded to the sparkplug and give it about 25 psi. This will give a clear indication of any leaks in the combustion chamber. Be warned though, you need to block the crankshaft so it can't rotate, because with 25 psi behind it the piston will take off like a rocket ship if it gets the least bit beyond top dead center.


----------



## CFLBob (Dec 25, 2020)

A very Merry Christmas to all reading this on the holiday.  

I would like to test the valve with a vacuum.  After the change to the taper, if I put the valve in the guide as it was supposed to work, but without the pin to keep it from falling out - it falls straight through.  Nothing's holding it in the valve guide.  When I try the test by sucking on it with my mouth, it doesn't open.  I don't know if I'm blocking it, though.  

Something like this Horrible Freight tester: 








						Vacuum Pump
					

Amazing deals on this Mityvac Vacuum Pump at Harbor Freight. Quality tools & low prices.




					www.harborfreight.com
				




The big problem is I have no idea what's good enough.  Just a number PFA (Pulled From Air) example, if I measure that 7 PSI opens it, is that good?


----------



## minh-thanh (Dec 26, 2020)

CFLBob said:


> The big problem is I have no idea what's good enough.  Just a number PFA (Pulled From Air) example, if I measure that 7 PSI opens it, is that good?


Are you asking about the pressure required to open the intake valve ?


----------



## CFLBob (Dec 26, 2020)

Yes, I was.  I'm trying to find out why it isn't working.


----------



## minh-thanh (Dec 26, 2020)

CFLBob said:


> but without the pin to keep it from falling out - it falls straight through.  Nothing's holding it in the valve guide.


It seems good enough for me, if it were me I would check the springs - if the exhaust valve is airtight
I don't test the vacuum so I don't know how much pressure is enough
And :
Check the valve block and  connections: make sure all are airtight


----------



## CFLBob (Dec 26, 2020)

Thanks for your input.  When I try the test of putting my mouth over the intake block, the exhaust valve isn't there.  I just have the top slice of aluminum with the valve cage in it.  I don't get the sensation of air coming through, like I do if I push on the valve.

What would happen if the intake valve wasn't sealed well?  It seems like it would open during my test anyway, and sealing well would keep it closed during the exhaust stroke.


----------



## minh-thanh (Dec 26, 2020)

Hi !
when I check the valve with the valve seat,
If it's airtight, I would turn the valve 45 and 90 degrees from the first position and check again. if all positions are airtight I'm sure the valve and the valve seat are airtight.
The truth is I haven't done the Webster engine yet
And I don't know what the valve block looks like 
I'm just speaking the way I know it on my engine


----------



## CFLBob (Jan 1, 2021)

In the last week, the parts for the fuel tank got in and I rebuilt it with the gasoline resistant cap and fuel line.  

I tapered the valve guides on both the intake and exhaust sides.   While everything was apart, I lapped the valves against the valve guides with 320 and then 500 grit optical grade abrasives mixed in some grease.  The area that had been ground was visibly changed.  

The exhaust valve was a little sticky in the valve guide so I built a little valve holding fixture to fine polish the shaft.  I ran the valve in the lathe, held 240 grit sandpaper on the stem for a while, then switched to 500 grit sandpaper.   If I hold the slice of valve block horizontally in the position where the valve should drop out, both valves drop freely.  The springs work well, everything seems like it should be working. 

When I crank the flywheel, I get no motion of the intake valve.  I tried adding another gasket, between the valve block and the cylinder head.  No difference.  I haven't tried fuel, yet, I'm just pessimistic about it working.  

As I've said a bunch of times, the only clues to compression I have are that if I take off the valve block and put my finger over the hole into the chamber, as the piston compresses the pressure will push my finger out of the way and make snorting sounds.  With the valve block and carb in place, Webster says that as you turn the flywheel it will make that sort of sound.  It does.  

I was thinking of just replacing the valve assembly with a little piece of sheet metal screwed into the holes that the valve block uses.   That should give me the feel test of the piston bouncing against the compressed air or resisting being pulled back.  

Before running in the engine powered by my drill, I found it really difficult to get the piston into the cylinder.  It would strange if it was too loose after running.


----------



## minh-thanh (Jan 1, 2021)

*"When I crank the flywheel, I get no motion of the intake valve. I tried adding another gasket, between the valve block and the cylinder head. No difference. I haven't tried fuel, yet, I'm just pessimistic about it working. "*

Put some oil w20 or w40 in the valve and the valve seat:
If you get some compression with it, your valve and valve seat aren't really airtight

Make sure: Cylinder and piston - rings are airtight !!
Because if they are not airtight then you cannot get the effects you say


minh-thanh said:


> *CFLBob*
> I usually test compression like this: when I pull the piston back to the BDC , when I release the flywheel ( without cylinder head , I sealed the cylinder  by hand )
> 1 / With piston and clean cylinder: piston will go up TDC about 1/2.
> 2 / piston and cylinder with a little oil w40: piston will go to TDC, or at least near TDC
> That compression is good enough with me.


----------



## wburnett2922 (Jan 2, 2021)

simple test but a bit messy remove spark plug fill cly about have full oil put plug back hand push piston against oil if any leaks you will see them bill


----------



## werowance (Jan 2, 2021)

hi Bob,  on my webster,  turning it over by hand i cant see my intake move either.   and with a video of it running i only see it move just a hair.  it doesnt open as much as th exhaust valve which is mechanicaly opened.
the spring on mine is very soft.  you can jus lay a finger on it with very little push and it will open.

do you have any old broken drills or grinders laying around?  i ended up getting the intake spring off the brushes of i cant remember if it was the drill or grinder - i had both laying in the corner broken.  they were very soft.  the exhust i just used a spring out of the kit.  

another thing i notice helps on mine.   squirt a good squirt of 5w30 (just what i had on the shelf for wifes Yukon) on the valves so it runs down the shaft and into the ports around the shafts.  i was just doing that to make sure they were lubed but then noticed it was easier to start when it was new.  once it broke in it became easier and easier to start.

good luck and dont let it get you frustrated.


----------



## CFLBob (Jan 2, 2021)

werowance said:


> hi Bob,  on my webster,  turning it over by hand i cant see my intake move either.   and with a video of it running i only see it move just a hair.  it doesnt open as much as th exhaust valve which is mechanicaly opened.
> the spring on mine is very soft.  you can jus lay a finger on it with very little push and it will open.
> 
> do you have any old broken drills or grinders laying around?  i ended up getting the intake spring off the brushes of i cant remember if it was the drill or grinder - i had both laying in the corner broken.  they were very soft.  the exhust i just used a spring out of the kit.
> ...



No broken old drills or grinders, but I have something that I should have thought of before.  Guitar strings.  The ones that are plain wire (not wire wound on wire) are music wire, and in particular, in one set of these I have a .013 and .010 diameter music wire about 3 feet long. If I need another diameter, there are other versions of string sets with different diameters.

I wound the intake spring with .015 music wire instead of the .013 that Webster calls for - because I have a lifetime supply of .015 from making the flame eater.  Sacrificing a set of guitar strings to take one to wind into a spring isn't as expensive isn't as buying the usual amount of music wire when you include shipping and all.  I may not even have to sacrifice a set.  I can replace the strings on one of the guitars and take the extra few inches I cut off to make the spring.  

As for the last line - too late!  A friend suggested I take time off and just let it stew in the back of my head.  I have some important "honey do" and "better do" jobs that can be full time for a week or so, including rearranging the shop.  Maybe I'll hook up the fuel and try it.  If it doesn't work, I'll stew on it for a week or whatever.


----------



## Steamchick (Jan 2, 2021)

FYI: Stiffness is related to the cube of the radius  - so for your wire: 0.015" diameter is 34% stiffer than the 0.013" wire - assuming the coils, wire material and temper, etc. are the same. A third more stiffness means the pressure to lift the valve on suction needs to be 3/4 of the pressure that opens the planned spring - so it probably makes a BIG difference to your engine. I had the same with an auto-valve on my flame eater...
K2


----------



## werowance (Jan 2, 2021)

Bob,i encourage you to make some springs as a learning process so that i can learn from you. but in the mean time meaning tomorrow ill look and see if i still have the other grinder brush or not.  if i do its yours,  just a postage stamp which ill pay for from VA to FL

but if you wind the spring please share as much info as you can.  yeah im asking for my benefit but i should say for eveyones.


----------



## CFLBob (Jan 2, 2021)

Look around post 286 on page 15 - from September.  I made the springs then and there was a lot of back and forth about it, along with the web page I've used as reference.  



			Making Springs on the Small Lathe


----------



## stevehuckss396 (Jan 2, 2021)

If you made the spring with larger wire, you will have a stiffer spring. Wind the spring with more turns per inch (finer pitch) than the plans call for and that should lessen the stiffness. Maybe Steamchick can do some more of those fancy mathimaticals and figure out how much of a change you would need to do to get you back to where the .013 wire would have been. Or if it's even possible to get there given the fixed length you have to work with.


----------



## werowance (Jan 2, 2021)

Thanks Bob, actually i did already read those posts and understood that you had already wound some springs.  thing is - i have never done it and wanted to learn as much as i could from you on it.  that said,  ill digress untill i get a chance to find the brush spring.  but you have a good one and good  luck in the mean time.  watching and hoping for you.


----------



## Steamchick (Jan 3, 2021)

stevehuckss396 said:


> If you made the spring with larger wire, you will have a stiffer spring. Wind the spring with more turns per inch (finer pitch) than the plans call for and that should lessen the stiffness. Maybe Steamchick can do some more of those fancy mathimaticals and figure out how much of a change you would need to do to get you back to where the .013 wire would have been. Or if it's even possible to get there given the fixed length you have to work with.


Pretty simple mathemateecals...: the 0.015" wire needs 30% more turns than the 0.13" wire to soften it. - Maybe a 30% longer valve stem needed? - Or reduce the pre-compression by 30% and you will have the same opening pressure, but only 2/3rds of the full open valve stroke... The engine should start, but be limited in performance compared to the correct spring. 
But there are other ways to "kill the pig" when you only have the "wrong" size of wire: Sometimes spring makers design springs to be barrel shaped... the required width at the ends, but tapering to up to twice the diameter in the middle, so to get the length of wire in fewer turns (due to the larger diameter). It's the length of wire that counts. e.g. A spring at 30% bigger diameter would only need the same number of turns as the design to compensate for the 30% stiffer wire....
Does that help?
K2


----------



## CFLBob (Jan 3, 2021)

Steamchick said:


> Pretty simple mathemateecals...: the 0.015" wire needs 30% more turns than the 0.13" wire to soften it. - Maybe a 30% longer valve stem needed? - Or reduce the pre-compression by 30% and you will have the same opening pressure, but only 2/3rds of the full open valve stroke... The engine should start, but be limited in performance compared to the correct spring.
> But there are other ways to "kill the pig" when you only have the "wrong" size of wire: Sometimes spring makers design springs to be barrel shaped... the required width at the ends, but tapering to up to twice the diameter in the middle, so to get the length of wire in fewer turns (due to the larger diameter). It's the length of wire that counts. e.g. A spring at 30% bigger diameter would only need the same number of turns as the design to compensate for the 30% stiffer wire....
> Does that help?
> K2



Steamchick your mention of wire diameter made sense when you posted it - not the cubic relationship specifically, just that thicker wire would take more force to move.  Steve's mention of more turns reducing the force to move the spring was not intuitive.  Since you're commenting on it, is that because with more turns, every little piece of wire moves less?  I can't see how more turns can affect the spring constant but maybe less length change as in Hooke's law?


----------



## Steamchick (Jan 3, 2021)

Dead right Bob! I thought to mention Hooke's Law, then didn't want to blind everyone with science. Spring constant goes down proportional with length of rod in torsion. A coil spring is just a straight torsion bar coiled for convenience... The stiffness of a beam goes up as the cube of the radius of gyration. (I think... Unless you can teach me otherwise?). But if you can teach me better, then great! I've never studied spring design, or read the books (I have some... maybe I should read them?). A man with a little knowledge (or the internet?) can be dangerous!
K2


----------



## CFLBob (Jan 3, 2021)

Steamchick said:


> Dead right Bob! I thought to mention Hooke's Law, then didn't want to blind everyone with science. Spring constant goes down proportional with length of rod in torsion. A coil spring is just a straight torsion bar coiled for convenience... The stiffness of a beam goes up as the cube of the radius of gyration. (I think... Unless you can teach me otherwise?). But if you can teach me better, then great! I've never studied spring design, or read the books (I have some... maybe I should read them?). A man with a little knowledge (or the internet?) can be dangerous!
> K2



Thanks for clarifying that.  

Likewise, I've never studied spring design, but unlike most electrical engineers, I took the class commonly called "Deformable Bodies" where everything bends, sags, expands and all those real world things.  I just don't recall anything that would help here.  But it has been many, many years since I cracked that book


----------



## CFLBob (Jan 6, 2021)

Just an input:  yesterday, I put some fuel in the tank cranked it for a while.  It still doesn't run, but it's getting closer.  For the first time, I noticed some popping sounds and could smell exhaust!  (I thought it was funny when I got the thought out of nowhere, "hey!  That smells like exhaust!")

I tried adjusting the carburetor a little, the lever that adjusts the amount of air, and there's a narrow zone in which that happens.  I didn't think of trying the low speed idle adjustment.

Still not running but the closest I've been so far.


----------



## minh-thanh (Jan 6, 2021)

CFLBob said:


> I noticed some popping sounds and could smell exhaust!



It's a signal of compression and burning of fuel 
If that's my engine, I'm sure it will run
Just adjust fuel, ignition timing or camshaft or or intake valve springs


----------



## Brian Rupnow (Jan 13, 2021)

Bob--What can I do to help? I've been where you are before, and it is terribly frustrating. Some things you can check---Take the sparkplug out and push a long piece of wire down the sparkplug hole. Set the sparkplug out on the engine block and turn the engine by hand with the ignition on. The spark should happen when the piston is about 1/8" before top dead center. (That's what the wire is for, to let you know where the piston is.). If you have run the engine in with an electric motor to loosen it up, then with the sparkplug in place give it a spin by hand. It should bounce back when it comes up on the compression stroke. If it doesn't bounce back, then either your valves aren't sealing or your rings aren't sealing. Take the sparkplug out, squirt some thirty weight oil into the sparkplug hole, then put the sparkplug back in. Spin it again by hand. If it bounces back now, then you know your rings aren't sealing. If it still doesn't bounce back, then your valves aren't sealing. Unhook the gas line from the carburetor and blow on it. You should hear it bubbling in the gas tank. (Make sure that the tank has fuel in it.)  Use the factory pre-sets on the carburetor if you are running an after-market carb. About 80% of small engines that won't run can be traced directly to the valves not sealing. As I said before, sacrifice a spark-plug by breaking the porcelain out of it and solder a tube of approximately 0.175" outside diameter into the sparkplug. Screw the modified spark-plug back into place and put an airline on it--give it about 20 to 30 psi (block the crankshaft so it can't turn unexpectedly). When the piston is at top dead center on the compression stroke, there shouldn't be any air coming out the carburetor nor out of the exhaust. Make sure when you are trying to start it that the engine is turning at least about 300 rpm.---Brian


----------



## wburnett2922 (Jan 14, 2021)

Bob if you are close to Sarasota bring Webster be glad to help get  her  running Bill Burnett


----------



## CFLBob (Jan 14, 2021)

Brian Rupnow said:


> Bob--What can I do to help? I've been where you are before, and it is terribly frustrating. Some things you can check---Take the sparkplug out and push a long piece of wire down the sparkplug hole. Set the sparkplug out on the engine block and turn the engine by hand with the ignition on. The spark should happen when the piston is about 1/8" before top dead center. (That's what the wire is for, to let you know where the piston is.). If you have run the engine in with an electric motor to loosen it up, then with the sparkplug in place give it a spin by hand. It should bounce back when it comes up on the compression stroke. If it doesn't bounce back, then either your valves aren't sealing or your rings aren't sealing. Take the sparkplug out, squirt some thirty weight oil into the sparkplug hole, then put the sparkplug back in. Spin it again by hand. If it bounces back now, then you know your rings aren't sealing. If it still doesn't bounce back, then your valves aren't sealing. Unhook the gas line from the carburetor and blow on it. You should hear it bubbling in the gas tank. (Make sure that the tank has fuel in it.)  Use the factory pre-sets on the carburetor if you are running an after-market carb. About 80% of small engines that won't run can be traced directly to the valves not sealing. As I said before, sacrifice a spark-plug by breaking the porcelain out of it and solder a tube of approximately 0.175" outside diameter into the sparkplug. Screw the modified spark-plug back into place and put an airline on it--give it about 20 to 30 psi (block the crankshaft so it can't turn unexpectedly). When the piston is at top dead center on the compression stroke, there shouldn't be any air coming out the carburetor nor out of the exhaust. Make sure when you are trying to start it that the engine is turning at least about 300 rpm.---Brian



My absence for the last week was due to another project imposing itself.  I had been saying for quite a while that when I laid out my shop I made some mistakes and wanted to fix them.  You know that made up stuff about walking 10,000 steps in a day?  I'd do that in a day in the shop going back and forth between the mill or whatever I was working on to get a drill bit or some tool.  I told myself I needed to add some bigger shelves and move things to be more centrally located.  

Over the holidays and early January, my wife and I talked and planned and then I spent the last week, cleaning and rearranging.  Do you remember these puzzles they had 50 years ago where you're supposed to put the numbers in order? You'd have to move a lot of things to get to the one you really wanted to move.  





That's like rearranging the shop.  I guess a more modern version would be Tetris with real things.

The good news is I think I'm done or close enough to done rearranging.  I was very encouraged by the ignition pops I was getting a week ago.  It happened over a narrow range of the lever on the carburetor.  I was going to experiment with the idle speed adjustment and see if anything made the pops more consistent over a wider range of movement of that lever.  

Brian, I was thinking about the strength of the intake valve spring and calculated that normal air pressure of 14.7 PSI would cause about 10 ounces of force if there was a vacuum on the cylinder side of the intake valve.  I measured how much force it takes on the valve to open it and that was about 5 ounces.  That tells me if the piston pulls even half the air pressure the spring would open.  I don't know if that's good or bad.   Would it be better if it took half that force to open that valve?  More?  Less?  

I don't have access to the compressor right now due to rearranging the shop.  Not sure how long it will take to be able to run your tests. 



wburnett2922 said:


> Bob if you are close to Sarasota bring Webster be glad to help get  her  running Bill Burnett



Thanks, Bill, but I'm in Melbourne, over near the Kennedy Space Center.  I think that puts us about 200 miles apart.


----------



## Rdean33422 (Jan 14, 2021)

I am in Weirsdale and welcome a visit.
I have four engines I built running so I have some experience.

Ray


----------



## CFLBob (Jan 14, 2021)

Thanks, Ray.  The same program says you're only 120 miles from me, so two hours instead of three.

I'll file this away.


----------



## werowance (Jan 14, 2021)

Bob, ill say you will not have nominal compression or vacume until it actually runs for a bit and the rings bed in.  i know this doesnt help with the how do you get it started but just to point out that the spring preasure cant be calculated like that until after everything is perfect.  i also see that you are saying even at half preasure it should be opening.   my only reason to point this out is so you dont assume bad things or bad machining or something based on math because the math cant compensate for break in under fire.  just need barely enough to get it to fire and then it will get much better.  - and i know i said i would shut up a few posts back lol.  so take it with a grain of salt and ill shut up again lol.  best of luck.


----------



## coulsea (Jan 15, 2021)

werowance said:


> Bob, ill say you will not have nominal compression or vacume until it actually runs for a bit and the rings bed in.  i know this doesnt help with the how do you get it started but just to point out that the spring preasure cant be calculated like that until after everything is perfect.  i also see that you are saying even at half preasure it should be opening.   my only reason to point this out is so you dont assume bad things or bad machining or something based on math because the math cant compensate for break in under fire.  just need barely enough to get it to fire and then it will get much better.  - and i know i said i would shut up a few posts back lol.  so take it with a grain of salt and ill shut up again lol.  best of luck.


I Agree the best way to seat valves and get rid of tight spots is under fire. it sounds like you were nearly there, put the throttle in the middle of the range that works and adjust the mixture while it is banging away. 10 to 15 second burst on the drill and you will get there. the mixture will need fiddling with as it runs in and even on different days, richer to start and lean off as it warms.
There are lots of annoying things that may happen like the timing slipping or trying to start it with a flat battery or no fuel, makes it all the more rewarding when it does run for the first time.


----------



## CFLBob (Jan 15, 2021)

werowance said:


> Bob, ill say you will not have nominal compression or vacume until it actually runs for a bit and the rings bed in.  i know this doesnt help with the how do you get it started but just to point out that the spring preasure cant be calculated like that until after everything is perfect.  i also see that you are saying even at half preasure it should be opening.   my only reason to point this out is so you dont assume bad things or bad machining or something based on math because the math cant compensate for break in under fire.  just need barely enough to get it to fire and then it will get much better.  - and i know i said i would shut up a few posts back lol.  so take it with a grain of salt and ill shut up again lol.  best of luck.



Don't shut up.  Until I post my video of it running, I'm trying to soak in all the advise I can get.  I don't have any answers on what's wrong, but I've been suspecting the fit between the piston and cylinder for a long time.  

I didn't even get to spend time in the shop yesterday - more house stuff.   After 5 days of rearranging things, now I can't find stuff that I put away.


----------



## CFLBob (Jan 16, 2021)

Brian Rupnow said:


> Take the sparkplug out and push a long piece of wire down the sparkplug hole. Set the sparkplug out on the engine block and turn the engine by hand with the ignition on. The spark should happen when the piston is about 1/8" before top dead center.



The spark appeared to be a bit over 1/8".  I measured about 5/32 or maybe a bit less; 0.155 is a good number.  The marks are a bit tricky to get high accuracy on.  Anyway, I marked a .125 mark on the other end of the wire and moved the cam a little a bit until the spark happened closer to there.  All I can say is it's closer.  

No difference.  I get pops and a faint smell of both exhaust and fuel.  The cylinder gets warm to the touch, the end without fins feels warmer than the fins and cylinder head, but I know it's trying.  It won't keep running.  I can feel suction if I put my finger over the intake on the carburetor.  It's not super strong, but easily felt.  If I mess with the idle mixture, the position of the throttle may make move, but the end result is the same.  



Brian Rupnow said:


> Take the sparkplug out, squirt some thirty weight oil into the sparkplug hole, then put the sparkplug back in. Spin it again by hand. If it bounces back now, then you know your rings aren't sealing.



Next thing to do.  I did it, but forgot the 30W oil.


----------



## minh-thanh (Jan 16, 2021)

I usually set the ignition  at 15 degrees before TDC, then, I start the engine, if the engine seems to want to run, I will adjust the  cam lobe a few degrees (in reverse and the same direction of rotation) If the change looks better I will adjust a few more degrees
   With intake valve springs: if it is too pressed or the valve body and the valve direction is not smooth, it will affect the intake of fuel  as well as difficult to adjust the needle.
with my engine: the intake valve spring only works to keep the valve in the closed position, and try to make the force of the spring as light as possible
Check the valve body and valve guide are still moving smoothly after  starts engine?


----------



## CFLBob (Jan 17, 2021)

@Brian Rupnow - would you look at this video?

This is the first test you mention.  I snap it into compression and the piston bounces back.  13 whole seconds, a few demos. 



No SAE 30 oil in there, just the piston, everything as it is while I'm trying to start the engine.  Is that enough?


----------



## stevehuckss396 (Jan 17, 2021)

seems a little tight. I would work on it until the crankshaft turns a little more free. Maybe the crank bushings are too tight. Maybe the ring is too tight in the cylinder. Hard to say but from the video it appears to want to freeze up. Does it turn better when the sparkplug is removed?


----------



## Brian Rupnow (Jan 17, 2021)

That looks okay to me. It's bound to be a bit stiff, since it's brand new. Take the sparkplug out, put a 6" pulley on it, oil everything up good, and then drive it for half an hour with an electric motor to take any stiffness out of it.---Brian


----------



## CFLBob (Jan 17, 2021)

I think I've run it with my battery powered drill (600 RPM?) for 45 minutes.  Maybe an hour.

I did some experiments while I was out there.  Raised my fuel tank a half inch and it started blowing oil and fuel onto everything.  I put down the starter and lowered the tank to the point that all the fuel ran back into the tank.  Then put the tank back on the holder and I could see the fuel getting sucked into the carburetor leading to the popping starting back up.  The carb. kept twisting in the intake slice so I put on some LocTite 680.  It will sit overnight before I try anything else.  

Steve - there have been times I was concerned it was too loose.


----------



## werowance (Jan 17, 2021)

Bob, if thats compression kick back as per the video then ill have to say you have more than me.
i cant say for sure but your symptoms seem simliar to mine at first. which i had a ton of problems

mainly i timed the spark cam with the crank going in the wrong direction.  that said i almost timed my valve timing in the wrong direction.   i would rotate the base arround and then lose my orientation and on top of that i had it in my head that the engine could run either direction (wrong) so at any rate that was my big deal.  in other words when i did gear valve timing i was looking on one side then on spark timing i was looking at the other side but when i spun the engine arroung each time i rotated the flywheel in the wrong direction. dont ask me why but when i spun it arroung i figured i needed to spin the wheel the oposite direction.

all that said.  if the engine will spin much free'er without the plug assuming the plug was inplace in  your test video shows then you have good enough compression.    if that test video was without the plug then yeah  its got some drag but should start and run badly at first with that much drag (assuming video was with plug)  hard to tell watching on my cell wthout glasses on.


----------



## minh-thanh (Jan 17, 2021)

As*  stevehuckss396 *and* werowance* said : seems a bit tight

I feel your engine seems a bit tight
but the important issue is that your engine have* pretty good compression .*
Again, with that good compression, I'm  sure the engine will run
Let's make it smooth


----------



## CFLBob (Jan 17, 2021)

werowance said:


> Bob, if thats compression kick back as per the video then ill have to say you have more than me.
> i cant say for sure but your symptoms seem simliar to mine at first. which i had a ton of problems
> 
> mainly i timed the spark cam with the crank going in the wrong direction.  that said i almost timed my valve timing in the wrong direction.   i would rotate the base arround and then lose my orientation and on top of that i had it in my head that the engine could run either direction (wrong) so at any rate that was my big deal.  in other words when i did gear valve timing i was looking on one side then on spark timing i was looking at the other side but when i spun the engine arroung each time i rotated the flywheel in the wrong direction. dont ask me why but when i spun it arroung i figured i needed to spin the wheel the oposite direction.
> ...



Just so everyone is on the same page, and new people come along to read, the spark plug is in the engine in that video.  

I think I've got the timing right, but now I'll check it again.


----------



## Steamchick (Jan 18, 2021)

Hi Bob, just and odd point. It looked to me that you need to remove the sharp corners on the flywheel to stop it shaving the skin off your thumb and finger? 
Maybe an arrangement to use you power drill for a starter is better anyway. But it looks like good compression to me. If you can make an adapter to fit in the plug hole and measure pressure, it should be a runner anywhere between 4 bar and 9 bar, but mixture varies with cmpression. Too rich wets the plug and won't  start, too lean won't fire and run.
Enjoy!
K2


----------



## CFLBob (Jan 18, 2021)

Steamchick said:


> Hi Bob, just and odd point. It looked to me that you need to remove the sharp corners on the flywheel to stop it shaving the skin off your thumb and finger?



To be honest, when I first saw this, my reaction was to look at my right hand to see where skin was missing, but I would have felt that.   No skinned areas or injuries. 

I've been using the method that werowance talked about - a rubber, automotive pinstripe remover in my cordless drill.  It seems to really do a good job.  The only drawback is leaving rubber shavings everywhere, but if my engine would run, it wouldn't be in contact long enough to matter.

I ran into a real point of confusion last night.  I went and looked at videos, and one of the first ones I ever watched, Pat Pending's Webster, is starting with flywheel going clockwise.   

This one starts going CCW   

I've been trying to start mine going CCW.  I thought Joe Webster said CCW from this viewpoint that these two videos show, but between these two, one has to be backwards.

*Edit to add:* I meant to just have links to those videos, not embed them.


----------



## scottyp (Jan 18, 2021)

The factors that determine which direction the engine will run are the exhaust valve cam and ignition cam timing. Take out the spark plug and connect the ignition.  Slowly turn the flywheel and think about what is happening vs what should be happening and when things are happening, through all 4 strokes.  It should only make sense it the flywheel is turning in the correct direction. Suck, squish, bang, blow.

OR - if you leave the spark plug in (without ignition) and turn the flywheel slowly.  In the CORRECT direction, you should feel compression on the correct compression stroke ONLY.  If you turn it in the WRONG direction, you will have compression whenever the piston is going into the cylinder and every other one of these compressions, you will get a puff out of the exhaust when you near top dead and the exhaust valve opens.

Just my observations...


----------



## awake (Jan 18, 2021)

Bob, I had similar almost-but-not-quite response from my Webster when I first attempted to start it. I moved the exhaust timing by one gear tooth, and on the next spin it started right up. Which is to say, it sounds to me like you are really, really close, and just need a small adjustment. Since you've already been working on compression and carburetor settings, and based on my own "vast" experience - as in, the Webster is the only engine I've built so far! - I'm putting my money on the exhaust timing.


----------



## CFLBob (Jan 18, 2021)

I need to ask a question about something I've noticed but never thought was wrong.  My spark plug fires on every stroke approaching TDC.

I decided to check my timing, the only way I know how.  This starts just before the start of the exhaust stroke, like Webster's diagram on the last page, how he set the cam.  I set my flywheel to the point where the exhaust valve just starts to open, then rotate between TDC and BDC.

Rotate to BDC - about 15 degrees, then...
Rotate to TDC - spark plug fires just before the top of the exhaust stroke
Rotate to BDC  - the intake stroke
Rotate to TDC - compression stroke and spark plug fires (with the piston about 1/8" before TDC)
Rotate to BDC - this is the bang pushing the piston down - where we started

The spark at the top of the exhaust stroke has no fuel to burn so I see it as wasted energy but not something that will mess up anything. 

Am I missing something?


----------



## awake (Jan 18, 2021)

Right - I think this is called a "wasted spark" configuration - ? In any case, the spark plug fires on every revolution, when it fires into the exhaust stroke, it does no harm.


----------



## scottyp (Jan 18, 2021)

The extra spark is a result of the ignition cam being driven from the crankshaft and closing/opening every revolution of the crank and nothing to worry about.

So, if your exhaust valve is opening about 15 deg before BDC at the end of the power stoke and closing again around TDC before the intake stroke begins, you should be good.


----------



## CFLBob (Jan 18, 2021)

Thanks, guys.  

The only thing I can think to do is to try to make my intake valve spring weaker.  I can't get over how I can see them moving on so many videos, while I know several guys here say they never see their valve move.


----------



## werowance (Jan 18, 2021)

seeing them move is i believe a product of camera trickery  if videoed right at the correct rpm  vs frame rate of the camera then you can see them move.  just started learning this on my upshur videos.  one i couldnt see the rockers move at all and the next i could.  at anyrate keep on truckin and good luck Bob.


----------



## CFLBob (Jan 18, 2021)

werowance said:


> seeing them move is i believe a product of camera trickery  if videoed right at the correct rpm  vs frame rate of the camera then you can see them move.  just started learning this on my upshur videos.  one i couldnt see the rockers move at all and the next i could.  at anyrate keep on truckin and good luck Bob.



I was thinking that, but my wife answers by holding her finger at the end of the valve and says she can't feel it move.  I know that I can move it and it seals, I've pushed the valve down, leaving the intake valve open.  It changes the sounds. 

But the new spring made no difference.  Still won't run.


----------



## CFLBob (Jan 19, 2021)

Today, a major breakthrough.  I got it to run, although not very well.  



One of those things I've meant to try was to use an old AC-powered Black and Decker 3/8" drill.  I compared it to my Ryobi battery powered drill and it seemed faster.  With the B&D it started almost immediately.  I realized I didn't have a camera and left it running to run into the house and get the camera.  Predictably, when I got back to the engine it stopped running.  The next several minutes were spent trying many combinations of the throttle setting and the position of my fuel tank.  The throttle lever is very sensitive, there's a narrow range over which it will run.  The tank seems better about 1/4" higher than my fixture was built for (I added some shims of 1/4" plate).  It's easy to add those in.

This is a major breakthrough, though.  The video has a surprise ending.  Well, it surprised me.


----------



## Brian Rupnow (Jan 19, 2021)

Bob---Congratulations!!! You are now a member of a very elite club---"Those who got their engine to run". I can see that you have a few things to address, but IT RUNS!!!!---Brian


----------



## werowance (Jan 19, 2021)

WONDERFULL NEWS!  CONGRATULATIONS.

you and I are using the same carb, so mine starts best on about 1/4 to 1/3 open on the throttle.  id say closer to 1/3.
I run straight coleman fuel.  I make sure the cylinder oiler is oiled up good and has had a chance to oil up the piston good before starting.   also is the cap on your fuel tank vented?  if not it wont run long.

maybe above info will help you get a more consistent start up.  but I think after you run it more and more it will break in better.

remember it will only run a few mins at wide open throttle as it heats up to much.  I guess I get about 10 mins run at idle speed - usually a screw or something vibrates loose by then anyway lol.

CONGRATS AGAIN.


----------



## werowance (Jan 19, 2021)

Bob, the surprise at the end - I have a video of mine doing the exact same thing.  carb falling off

also the head appears to be moving a lot.  - speaking of the screws coming loose - mine keeps getting loose there as well.  the 2 side screws get loose as well as the larger bottom screw going through the base plate gets loose.

green locktight on the carb is finally what held it in place on mine.

but yours runs really good Id say.


----------



## awake (Jan 19, 2021)

CONGRATS!!!! Perseverance paid off! And what do you mean, "not very well" - sounds just fine to me. Well, maybe not at the _very_ end of the video ...


----------



## scottyp (Jan 19, 2021)

Good job Bob!  Seems to run fairly smoothly.


----------



## cheepo45 (Jan 19, 2021)

Congratulations!
This is why I keep building I.C Engines.
The longer the struggle, the more exciting it is when it finally runs!
 Scott


----------



## CFLBob (Jan 19, 2021)

Thanks, everyone.  Especially, thanks for the help all along the way, everyone.  



werowance said:


> you and I are using the same carb, so mine starts best on about 1/4 to 1/3 open on the throttle. id say closer to 1/3.
> I run straight coleman fuel. I make sure the cylinder oiler is oiled up good and has had a chance to oil up the piston good before starting. also is the cap on your fuel tank vented? if not it wont run long.
> 
> maybe above info will help you get a more consistent start up. but I think after you run it more and more it will break in better.
> ...



I think that's right where my carb throttle is set, right in that 1/4 to 1/3 area.  I basically can't touch the throttle lever without stalling it.  It's very touchy.  Since I can't touch the throttle, it's running at whatever it thinks it's set to.  I can't adjust the speed of the engine up or down.  

I don't have an oiler on the cylinder.  I put a drop or two in the hole on top of the cylinder for it before I go to start it up.  I could always add that.  

My fuel tank is an RC Tank with a vent in it, so check on that.  



werowance said:


> Bob, the surprise at the end - I have a video of mine doing the exact same thing. carb falling off
> 
> also the head appears to be moving a lot. - speaking of the screws coming loose - mine keeps getting loose there as well. the 2 side screws get loose as well as the larger bottom screw going through the base plate gets loose.
> 
> ...



I tightened the big screw in the bottom of the head, but not the side screws.   It doesn't really feel like it's moving when I press on the cylinder when it's not running, but it's very obvious when you watch it. 

There's green LocTite on the other end of that adapter on the carb, where it plugs into the intake valve in the stack.  A little where the carb plugs into the adapter will be easy.  


I'd like it to start more reliably and not stall out if I touch the throttle or the engine shaking it makes it move.  To be able to push the throttle open and have it speed up would be really cool.


----------



## coulsea (Jan 20, 2021)

good work. Be patient it will improve as it runs in, particularly the valves. It will start and run at lower speed once it is run in and when it will start reliably you can adjust the intake valve spring so that it closes the valve with very little tension when closed, this improves the efficiency of the intake stroke and makes it much easier to start at lower revs.
But be patient get to know it and start it every day for a week before you make mods.
you will not get the full use of the throttle movement but you should be able to significantly alter the revs.


----------



## Steamchick (Jan 20, 2021)

Bob, "You have done a better job than I, Gungadin" - to quote some famous Author.
WELL DONE SIR! I am impressed. 
Ignoring the carb  - and other little snagging jobs you'll sort in days to come - the real concern I have from watching the video is the L-shaped engine mounting. It definitely  is not stiff enough and will wear the piston and bore badly with all the movement from the flexing of the mount. You must make a much stiffer mount. Maybe some side-plates - triangular - to seriously stiffen the bracket you have?
Also make a cylinder oiler. Worth it for keeping the piston from wearing, and it will help cool the piston and cylinder by helping conduct heat from piston  to cylinder wall as well as keeping friction to a minimum. You can even black the cylinder and head to improve radiant cooling of the cylinder and head. Most air-cooled motorcycle engines are black for thar reason. Better than risking a seizure! I know people think shiny metal looks nice, but black is part of the engineering of the cooling system. And it can make a model look "professional".
Just my humble advice..
Enjoy running your fine model. Real proof of your skill and effort.
Regards, 
K2


----------



## werowance (Jan 20, 2021)

Bob, could you post some pics of the spark plug wire please.  looks smaller than a normal plug wire and just interested to see what you used and how it looks.  from what i see i like it.


----------



## awake (Jan 20, 2021)

Bob, at the risk of telling you things you already know ...

The touchiness of the throttle may be due to either / both the mixture setting and the spark timing. Get the engine running, then experiment with the mixture. You'll pretty quickly get a feel for the range in which it runs best. (Note that it will want to be richer when cold, leaner as it warms up.)

As for spark advance, I don't recall if you included any adjustment. I would say that this makes less difference on my Webster than I expected, but in general the closer the timing is to TDC, the easier it will start, but the less well it will accelerate or run at higher speeds. Advancing the timing too far can lead to the opposite - hard to start, but eager to run at higher speeds. Again, with the engine running, adjust the advance (if it is adjustable) until you find a happy medium.


----------



## CFLBob (Jan 20, 2021)

Werowance,  

Does this help?   







The spark plug wire came with the electronic ignition from Roy Scholl at Roy's CDI Ignition Systems  I'm not sure what gauge wire that is but it's a thick insulation and the cap on the plug is softer than I remember those being on any car I've ever worked on.  The thin black wire is the ground, and it goes to a screw I added in the cylinder head when I was wiring it up.  

The black module is the electronic ignition, the white wire going under the fuel tank holder is the points contact to that.  The battery pack that runs it is at the top.  The green wire jumpers out one battery in a holder that I had lying around that holds 4 AA batteries, so it turns a four cell holder into a three cell.


----------



## Steamchick (Jan 20, 2021)

Hi Werowance. Just a couple of comments about HT cable. As the spark energy is high frequency, it is susceptible to the impedance of the circuit, including the spark plug. Manufacturers of systems optimise the system usually by using the optimum HTC cable resistance, capacitance and inductance (combined as impedance) different diameter and insulation designs are of different capacitances, and different 'wires' can be of varied resistances and inductances. . .. So you need the correct HTC cable as specified by the system manufacturer for best performance. Of course, often you can 'manage' with a different design of cable, but it risks higher voltages appearing inside the 'spark generator' (coil, capacitor, trick box, etc.). The wrong cable can mean poor sparks at full throttle - when the spark has the highest resistance to break-down the gases in the combustion chamber and generate the spark.
Take care,
K2


----------



## werowance (Jan 20, 2021)

Thanks, I'm just using a car plug wire for a ford coil.  I think I asked for a 1976 Lincoln continental coil wire. and just a regular old ford coil driving it.  it works fine on mine but was curious if there wasn't something a little nicer for a model engine is all.

the Lincoln is the model my parents had when I was a little kid.  I stayed car sick and I called it the vomit comet as I got sick everytime I got in that thing.  had that strong smell of leather, was dark blue almost black, and the ride was In all different directions.  the car didn't just spring up and down but seemed to "float" in all axis's all of which just made me sick as could be......   but that's another story I guess.


----------



## Eccentric (Jan 20, 2021)

Fantastic Bob, Congratulations.  The video is awesome.


----------



## minh-thanh (Jan 20, 2021)

A beautiful Webster engine .
Congratulations !


----------



## ZebDog (Jan 21, 2021)

congratulations sir on getting your Webster engine running.
I had the same problem with the head rocking back and fourth I fixed it by putting two extra 4mm screws in the bottom, it worked for me.


----------



## Steamchick (Jan 21, 2021)

werowance said:


> Thanks, I'm just using a car plug wire for a ford coil.  I think I asked for a 1976 Lincoln continental coil wire. and just a regular old ford coil driving it.  it works fine on mine but was curious if there wasn't something a little nicer for a model engine is all.


Hi Werowance: On ignition systems: Ford and "the rest" had different strategies for coils - from what I learned in the UK "as a lad".
Most 12V cars (in the world) used 12V coils. But back in the days of yore - when battery electric systems were first designed to replace magnetos - the Batteries had times when they were at very low voltage when cranking - so the sparks were weak and with an aged battery customers complained of poor starting. Ford decided to overcome this by using a 6V coil + Ballast resistor, which allowed the coil to run safely on the 12V system. When the starter button was pressed, the feed to the starter solenoid also fed the coil - thus by passing the ballast resistor and allowing "full battery voltage during cranking" to provide the sparks. As the batteries typically dropped to between 9V and 6V during engine cranking, the customer got really good sparks and a much more reliable starting system. I think this allowed Ford to use slightly smaller batteries and the cost saving off-set the cost of the extra wire and ballast resistor. I think many Fords had this certainly up to the 1970s, and really no reason to change until coil-on-plug became the way to go. I don't know if any other manufacturer used this arrangement? - So is your Ford coil a 6V job?
As an alternative, for a small 6V coil for your next engine, you could research using a Honda step-through (50cc to 90cc motorcycle) coil, or something similar? - e#@y has stuff for around $20 from China, complete with HT cable and regular automotive plug-cap. e.g. 6V Ignition Coil with Cap For Honda CB100 CL100 SL100 XL100 CB125S CL125S SL125 . Then all you need is the contact breaker, condenser and 6V battery? May be cheaper than Roy's CDi stuff, but his will be good and reliable if you don't want to assemble your own "old fashioned" coil system?
Enjoy!
K2


----------



## CFLBob (Jan 25, 2021)

After a dab of green LocTite (680) and letting it cure overnight, I sat down to start the engine, with the idea of letting it run once a day for a while.  It simply would not start.  While figuring out what was wrong, I tried tightening the screws to reduce the wobble as the piston moved, but they were already tight.  I found the batteries in my electronic ignition needed to be replaced, and the lower level of fuel in the tank made positioning it  difficult.  It eventually did turn over a few times, but wouldn't keep running.  The vibration was so bad that the carburetor throttle lever would bounce out of the range it works over.  

Last week @Steamchick had mentioned a triangular brace on the other side of the head, so I started thinking about that.  The first thing I did was pull the drawings back up - this is on sheet 4 of Webster's plans.  He left out all hidden lines on the head "for clarity" (a note in the top left).  I started adding the hidden lines so I could see where everything was.  The top of the head is probably the best place to put a reinforcement, since the force from piston pushing on the head produces the most torque farthest from the base, but there's no more than 1/4" of wall up there to drill and tap without breaching the combustion chamber.  

I eventually added two #8-32 screws in the base, on the opposite side of the 6-32 screws that hold it to the side frame.  Adding in the hidden lines allowed me to see the screws coming in from that side would hit the #10 screw that holds it to the base.  I displaced them "forward" (farther from the flywheel), which looks to the right in the view on the plans.  So I redrew the head from the other side (where the cylinder used to be) to show the way they look from the side looking at the engine.  This screen capture off my computer should help show it.  Dimensions in black are all mine, the bottom half is all mine, the notes in black are mine.






The bottom half shows the bracket that would be flush with the front of the head, adds two screws on the left, 0.160 from the end, and two screws in the bottom.  The head is shown with bracket copied onto it on the right.  

A little search around the shop led me to a piece of scrap the same thickness as the side frame (5/16" or 0.313").  Coincidentally, almost exactly the distance from the edge of the head to the edge of the base plate.  The scrap had an odd shape, but I just needed to trim and square it up a little to have something usable.  A second search led me to find exactly two screws for each of the two places.  That meant I had what I needed to clean up the scrap and make a brace.  I spent some time trying to figure out how to do this without disassembling the entire engine.  I figured I'd clamp that bracket to the head and use it as a guide to drill and tap the new #8 holes.  Once the holes were in the side of the head, I could pull the bracket off, move the engine over to the CNC mill, zero on the vertical line where the new screw holes are, use the 1.586" calculated distance from there to the first, new vertical hole, and drill through the base plate.    

It actually all went together easily.  Pay no attention to the fact that the two 8-32 screws on the side holding the new bracket don't match.  One isn't stainless.   That's just cosmetic.  






By the time I finished this, I had used up the afternoon, so I don't even know if it works yet.  I think that curved surface on the top of that bracket or brace or whatever you call it needs some more finish work


----------



## Steamchick (Jan 25, 2021)

Thanks Bob! I'm humbled that you have followed my advice. Looks much better now (to me). Hope it fixes the wobble?
K2


----------



## Brian Rupnow (Jan 25, 2021)

Bob--you may have missed it on the plans, but there should be two #6-32 flat head bolts positioned directly across from the new bolts you put in which hold the long crankshaft support plate against the side of the cylinder head plate. There is also one bolt up from underneath the base which threads into the bottom of the cylinder head plate.--EDIT---I have just looked back to the beginnings of this thread and seen that you have the holes in the appropriate places. If these bolts are in place and tightened, there is no way the cylinder head should have been wobbling around like it was in the video.-Brian


----------



## CFLBob (Jan 25, 2021)

Brian Rupnow said:


> If these bolts are in place and tightened, there is no way the cylinder head should have been wobbling around like it was in the video.-Brian



All three are in place and I can't tighten them any more.  Any ideas what I could look for?  

Pretty much the only thing I can think of is that the screws are bottomed out early - too long - so that the screw won't go in any further, but don't bear enough load onto the base and side frame.  That doesn't seem to be the case.


----------



## CFLBob (Jan 25, 2021)

Steamchick said:


> Thanks Bob! I'm humbled that you have followed my advice. Looks much better now (to me). Hope it fixes the wobble?
> K2



Not at all.  Credit where credit is due, after all.


----------



## Brian Rupnow (Jan 25, 2021)

Check the screws for bottoming out. If they are doing their job, there is no way that plate can wiggle around.---Brian


----------



## werowance (Jan 25, 2021)

Steamchick said:


> Hi Werowance: On ignition systems: Ford and "the rest" had different strategies for coils - from what I learned in the UK "as a lad".
> Most 12V cars (in the world) used 12V coils. But back in the days of yore - when battery electric systems were first designed to replace magnetos - the Batteries had times when they were at very low voltage when cranking - so the sparks were weak and with an aged battery customers complained of poor starting. Ford decided to overcome this by using a 6V coil + Ballast resistor, which allowed the coil to run safely on the 12V system. When the starter button was pressed, the feed to the starter solenoid also fed the coil - thus by passing the ballast resistor and allowing "full battery voltage during cranking" to provide the sparks. As the batteries typically dropped to between 9V and 6V during engine cranking, the customer got really good sparks and a much more reliable starting system. I think this allowed Ford to use slightly smaller batteries and the cost saving off-set the cost of the extra wire and ballast resistor. I think many Fords had this certainly up to the 1970s, and really no reason to change until coil-on-plug became the way to go. I don't know if any other manufacturer used this arrangement? - So is your Ford coil a 6V job?
> As an alternative, for a small 6V coil for your next engine, you could research using a Honda step-through (50cc to 90cc motorcycle) coil, or something similar? - e#@y has stuff for around $20 from China, complete with HT cable and regular automotive plug-cap. e.g. 6V Ignition Coil with Cap For Honda CB100 CL100 SL100 XL100 CB125S CL125S SL125 . Then all you need is the contact breaker, condenser and 6V battery? May be cheaper than Roy's CDi stuff, but his will be good and reliable if you don't want to assemble your own "old fashioned" coil system?
> Enjoy!
> K2



Hi Steam chick,  mine is a off the shelf ford Lincoln continental coil.  i made a coil kit in a box that i can move to my other engines.  there is an external ballast resister on it.  it runs on 12 v.  i  make my engines with quick connects to  the points setup and then the spark plug wire to the plug.  i use a 12 v gell cell alarm battery to power it with all held together inside a converted ammo can.

i use this same setup on old 6 v tractors when i convert them to 12 v for example a few farmalls i have done.  delco 4si alternator and the coil / ballast resister.  honestly the 6v coils work fine with 12 v on the farmalls but they are usually in such bad shape when i see them full of white corosion or the the metal case rusting through that i change them out.

all that said,  i just thought Bobs plug wire looked neat and nice and wondered where he found a coil wire that small.  my full size one works great and is only connected when running them.


----------



## CFLBob (Jan 26, 2021)

Short version of the story is this seems to make all the difference in the world.  Steady as can be.  Unfortunately the engine is still being a pain about not starting reliably.

While I was troubleshooting, I noticed the red LED on the ignition would show the spark going off when the cam wasn't in the right position, and then not sparking when it was supposed to.  My points have crapped out.  I mentioned before that they would stop moving and wouldn't work until I oiled them.  That isn't working today.  It has been since the early 80s that I worked on an engine with mechanical points and I never oiled points.  

I think it's time to get some new ones.  These were from NAPA.  Based on these, I wouldn't go back for another set.


----------



## awake (Jan 28, 2021)

Bob, for no particular reason other than easy availability, I used a points set for older Ford tractors - readily available for not much money on Amazon, but also through places like Tractor Supply. I have no idea if this was the best choice, but it has certainly worked reliably for me on my Webster.


----------



## Brian Rupnow (Jan 28, 2021)

Bob--If you are holding those points in place with a #10 bolt, they won't operate freely. Run a 3/16" drill thru the points mounting hole and then put a dab of Loctite on the bolt threads and don't tighten it down--just run it into the threaded material until the underside of the head just barely touches the points, so that the points are free to rotate. You should be using a #6 pan head bolt thru the slotted hole in the points, and it should be snugged down to set the points gap.


----------



## CFLBob (Jan 28, 2021)

awake said:


> Bob, for no particular reason other than easy availability, I used a points set for older Ford tractors - readily available for not much money on Amazon, but also through places like Tractor Supply. I have no idea if this was the best choice, but it has certainly worked reliably for me on my Webster.



Andy,  I recall your post about the Ford tractor points from a couple of pages ago when I was first posting about some issues.  Someone else posted about these CH14VT points and they got a set for a couple of bucks.  I ordered these yesterday:








						Contact Set Standard CH14VT And Ignition Condenser AL111 AL-111  | eBay
					

Find many great new & used options and get the best deals for Contact Set Standard CH14VT And Ignition Condenser AL111 AL-111 at the best online prices at eBay! Free shipping for many products!



					www.ebay.com
				



Just because they were about $5 less, including shipping, than the Ford tractor points on Amazon.  



Brian Rupnow said:


> Bob--If you are holding those points in place with a #10 bolt, they won't operate freely. Run a 3/16" drill thru the points mounting hole and then put a dab of Loctite on the bolt threads and don't tighten it down--just run it into the threaded material until the underside of the head just barely touches the points, so that the points are free to rotate. You should be using a #6 pan head bolt thru the slotted hole in the points, and it should be snugged down to set the points gap.



When I was building the support where the points are mounted, I made the mistake of making both holes 10-32 instead of 8# on the left and #10 on the right, like Webster drew it.  I've used a #10 pan head screw on the slotted hole, and needed to widen the slot with a needle file.  On the #10 side, I drilled out the hole, but I don't recall if it was a full 3/16 or slightly smaller.  

The points seem to have been ruined, so I need to approach this more carefully when the new ones get here.  Right now, if I squeeze the points to open them, they won't spring back to closed.  They just sit there open.  If anything, I'll drill out the points with something bigger than 3/16.  If it looks like the metal can bear it.  The drill size chart I have for tapping holes says a "Free Fit" for a hole to pass through to get to a tapped #10 hole is 0.201 and close fit is 0.196.  3/16 is quite a bit smaller than the close clearance number they give.


----------



## Brian Rupnow (Jan 28, 2021)

Bob--Pick up a #10 bolt and measure it across the threads with a vernier. They measure 0.188" diameter. A 3/16" drill will always make a hole about .0005" over. You won't end up with a lot of clearance, but there will be enough to let the points rotate freely.


----------



## awake (Jan 29, 2021)

Aha - the discussion about the #10 bolt has made me aware of a key difference between the type of points you are using and the tractor points I used. If I am understanding correctly - and based on the pictures in the eBay ad - the points you are using have one of the screws that secure it in place passing through the "hinge" of the points. Is that correct? On the tractor points, the securing screws do not pass through that hinge, so no binding occurs. That was not a matter of planning or wisdom on my part - I just lucked out on the points I happened to use!


----------



## CFLBob (Jan 29, 2021)

Exactly right, Andy.  The #10 screw goes through the part that the spring wraps around - the hinge.  

This support piece for the crankshaft was the second or third piece of the engine I built.  I built the cylinder head first, and then did the two sides.  If I had really understood the drawing and that I was making the mounting location for the points, I might have gone to my auto parts store, found the cheapest points they stocked that looked good, and laid out the holes for those.  The points that Webster specifies are available, it's just that no shop in town has them, and they all required I make two trips to the store.  

Since the post office says the points will be here Monday, I may as well dissect these.


----------



## CFLBob (Feb 3, 2021)

OK, the new points came in on Monday (they were promised tomorrow), but due to some veterinary problems, I just got to put them on the engine today.

They didn't work.  I couldn't measure continuity with an ohmmeter between the contacts with them off the engine and closed.  I looked at the points under magnification and saw some sort of film on them.  Scraped.  Ran brown paper over them, finally 400 sandpaper before they worked.  

Then I convinced it to run for another minute and change.


----------



## werowance (Feb 3, 2021)

that was a pretty consistent run id have to say.  the stabalizing bracket seems to have worked very well.  with your permission i might copy that idea over to mine.  i couldnt see any rocking happeing on the head block. hope all is well with the animal.   and the webby is looking good.


----------



## CFLBob (Feb 3, 2021)

The cylinder is much more solid this way.  The last time I tried to start it, the vibration would shake the carb's throttle out of whatever place I set it.  Now it's really steady.  

Feel free to try it.  I don't think anyone needs my permission.  I probably need Joe Webster's permission for modifying his engine!


----------



## awake (Feb 4, 2021)

Very nice - but what a puzzle that you keep having problems with the points. A basic engine component that has been in existence for what, 100 years? Having to fight with them almost makes the effort seem ...

... wait for it ...

... pointless!


----------



## wburnett2922 (Feb 4, 2021)

points have always been a problem. I just installed set on model I am building same problem rub with old fashion point file problem solved why do you suppose the auto co. went electronic remember back in good days always carried point file. I am 92 started with 23 chevy superior Bill


----------



## CFLBob (Feb 4, 2021)

This is my third set of points.  The first set didn't ever try to run.  I just ordered the wrong part number.  It met the description from Webster's sheet 21, but didn't have the connection to the other end of the spring steel on the moving contact. 





						Yet Another Webster Begins
					

(we know them as 'side-cutters' down here)   I grew up calling them dikes, short for diagonal cutters.  When you're building electronic stuff, they're among the most used tools.




					www.homemodelenginemachinist.com
				




My next set, the ones that just quit working, were used the longest but I noticed the problem with them not closing not long after I got them.  I actually took them off the engine, squeezed them open and they wouldn't close.  After poking and prodding for a few minutes, I put a drop of oil in the right side around where the sheet steel spring goes around the screw boss, and they started working.  And worked until they didn't anymore.  Did I kill them by tightening the 10-32 SHCS too tight?  I don't know.  

This third set is a set of CH14VT from eBay.  I'm starting over on the counter of how long they'll last. As Brian suggested, I put the SHCS in without putting any pressure on the points, and hold the screw with a little LocTite 680 (green) on the screw.  

I noticed that in yesterday's video, I can see the intake valve moving a little.  That's first time I've seen that.


----------



## Vietti (Feb 4, 2021)

I have been using 1974 MG points in my magnetos as they about the smallest I can find.  Anyway they are well made and seem to work well with modifications to fit the mag.  I get them from the auto parts store. 

Anyone aware of a smaller set of ignition points??

Thanks, John


----------



## CFLBob (Feb 4, 2021)

Vietti said:


> I have been using 1974 MG points in my magnetos as they about the smallest I can find.  Anyway they are well made and seem to work well with modifications to fit the mag.  I get them from the auto parts store.
> 
> Anyone aware of a smaller set of ignition points??
> 
> Thanks, John



That would be a useful thread on its own!  Imagine a list of points and sizes.  These have two holes spaced 1-1/16" apart, one is supposed to be #10 and other #8.  Is that some sort of standard?  If I knew points other than the one Webster calls out, I might have found a set I could just walk into my local stores and buy.  As it is, all three chains in town had to order from out of town, and required me to drive there to order and to pick up.


----------



## Brian Rupnow (Feb 4, 2021)

Bob--I use Chrysler points part # 018-4126-8   A110P  on all of my engines. I have never had a problem with them on over 20 engines. If you do like I say and run a 3/16" drill thru the main attachment hole, then they do accept a #10 cap screw. Don't run the screw down and tighten it, because the points do have to rotate there a bit.  A bit of Loctite on the bolt threads keep it from unscrewing. The other bolt which lets you adjust the opening of the points should be a #6 pan head bolt. You must also use a condenser, or the points rapidly burn out. I use a condenser # 018-1555-4   G120P. ---Brian      My Partsource automotive store knows that I build these engines, so they always keep a set of points and condenser and an NGK sparkplug CM10 in stock.


----------



## wburnett2922 (Feb 4, 2021)

Auto parts stores generally have 72 any model Chrysler points in stock as far as I know most or all are made in Mexico they seem to work 3/16 drill thru #10 hole is very good idea and you certainly need condenser auto parts store need car model and year to look up parts try 72 Chrysler  shough work.


----------



## wburnett2922 (Feb 4, 2021)

Also if you place paper bill$ between points pull through will generally clean so they will work  
Of course if you paid  10$for points you would have to use larger money  amount . bill


----------



## CFLBob (Feb 8, 2021)

No video, and nothing about points.  (Yes, a pointless post)

I'm just wondering what to do next.  I can ordinarily get it to run after a few tries, and it will run for maybe a full minute.  I've gotten it to run a bit for several days.  If I keep trying to restart it, I can get it to run for maybe two full minutes.  The carb throttle lever is EXTREMELY sensitive.  There's no such thing as using the lever to goose the engine and have it speed up and then slow it down.  

The lever is open around 1/4.  It's almost straight out over the air port.

The engine seems to run fast.  I'm bad at judging this, but maybe a thousand RPM?  It seems to stop running because the cylinder gets too hot.  (I keep telling myself to get one of those "laser tachometers")

So I'm here to ask questions of you guys who are way ahead of me in this world.  

First off, is this pretty much what it's going to do?  Am I likely to get it to run much better?  Since the throttle is barely open, which way would I try to adjust the screw, more open or more closed?  

Is it time to clean it up, mount it on a plaque, and try to do better on the next engine?


----------



## Brian Rupnow (Feb 8, 2021)

1000 rpm is about what you can expect for idle speed with these engines unless you go to a really heavy flywheel like I did on mine, then you MIGHT get down to around 800 but that's pretty questionable. My Webster will run all day without stopping from being to hot, but thats more a matter of what ring you used and how closely the piston fits in the cylinder. Some people have changed the cylinder so that it has a water-jacket for cooling water around it to get around the overheating, and some people have fitted a small fan driven by an o-ring belt to blow cooling air over the cylinder.


----------



## CFLBob (Feb 8, 2021)

That's interesting.  Can you change the throttle position and change speeds, or is it touchy and shuts down easily?  I'm guessing you can adjust it.

I used cast iron piston rings from Dave Reed, and all I honestly know is all the compression tests seemed OK before I got it running.  I've run it with an electric drill turning the flywheel for most of an hour, and might have another 10 minutes total time running itself, spread out over days.   

I've watched a few videos on YouTube of various Websters and they seem to run the minute or two of the video, so I thought maybe that was all I could expect.  

What I've been thinking is that the engine runs with the throttle close to minimum, that closes off the air input as if it was choked and makes the fuel/air mixture more fuel-rich, right?  Maybe it needs a richer fuel air mixture.  I guess that means I should open the idle speed screw?    Or the low-speed mixture screw on the right?


----------



## Brian Rupnow (Feb 8, 2021)

If the engine dies out when you increase the throttle, it is because the carb is running too lean. You need to adjust the mixture needle to richen up the amount of fuel being admitted to the carburetor as much as you can at idle. That will help a lot when you open the throttle. Ignition timing plays a role in this as well. You have to advance your ignition timing as much as possible when the engine is idling, because these Webster engines have no automatic spark advance on them, and higher revs require more advanced timing.


----------



## werowance (Feb 11, 2021)

Bob,  this is a bad way to describe it but if using regular straight coleman fuel,  my carb which is the same model as yours,  when adjusted to what i call the best response but hardest to start is rich.  it will spray oil / fuel out the exhaust sort of like an rc car runnign on nitro (just not as bad).  it starts better on lean (i dont mean extremely lean) but if its spraying fuel / oil out then it responds better when its running.  now that said its hard to "goose" it but you can rev it up and it hold a good rev when very rich.  you can slow goose it if that makes sense.  or at least thats what i found on mine before i put it on the shelf


----------



## CFLBob (Feb 12, 2021)

werowance said:


> it will spray oil / fuel out the exhaust sort of like an rc car runnign on nitro (just not as bad). it starts better on lean (i dont mean extremely lean) but if its spraying fuel / oil out then it responds better when its running.



I think mine is close to what you describe, but I can't seem to advance the throttle at all.  It seems to spray a lot of oil, and I don't even have any oilers on it.  I put a drop of oil in the piston oiler hole and a little in the intake valve guide, that's about it.  Look at the engine in my last video of it running.  It's covered in oil.

Better yet, I did a screen capture of it.  There's oil you can't see on the cylinder head, too.  It seems to ooze out of everywhere.  






Been wrapped up in other things to do, but something occurred to me.  I've messed with the high-speed mixture and idle speed screw by that diagram.  I never touched the low speed mixture screw.  The instructions don't say much about it.  

I ran across a YouTube video that runs really sweet.  This is how I'd like mine to run.


I think I'm going to make something to put on the crankshaft so I can start it with the drill there, rather than with the pinstripe eraser.  The one I got covers everything in eraser dust.   You can see it on the base under the edge of the flywheel.


----------



## awake (Feb 12, 2021)

That's a beautiful example of a Webster!

My experience echoes Brian's and Weworance's but maybe is not quite identical. On first start, it works best if it is a little rich, throttle maybe half-open. After warming up for 30 seconds, it starts to labor a bit until I lean it out some. As Brian said, lean it out too much, and it won't throttle up very far, so it is a balancing act.

Keep in mind, my experience is using a Chuck Fellows style carburetor; it has only a mixture needle and a throttle screw. The mixture needle setting is very sensitive - only very small movements make a significant difference.

You will definitely benefit from a different mechanism to transmit rotation from the drill to the engine. It really helps if you can run the drill continuously (turning over the engine continuously) while adjusting the carburetor settings until it begins to fire. I would think it would be hard to accomplish that with a friction transfer.

One last thought - go easy on the oil. I find that it doesn't take much, and doesn't have to be applied all that often, at least not for the 1-2 minute runs that I do.

Hang in there - it has run before, so you know a living engine is in there somewhere!


----------



## Vietti (Feb 12, 2021)

Have you considered a sprang or one way clutch for your starter?  They work well and are widely used.  BOCA bearings is a good source.


----------



## CFLBob (Feb 12, 2021)

Vietti said:


> Have you considered a sprang or one way clutch for your starter?  They work well and are widely used.  BOCA bearings is a good source.



I've never heard of them!  Time to go do some reading.


----------



## Vietti (Feb 13, 2021)

Maybe some one with CAD skills can provide a quick drawing of how to make these work, they really are the cats meow. 

 On my hit and miss engines I use a female clutch in the drill and engage the end of the crank shaft or a crank extension if too short.  The clutches are supposed to run on a hardened shaft but you can get away with a non hardened shaft for a while, then sleeve it with a a hardened collar.


----------



## CFLBob (Feb 13, 2021)

Vietti said:


> Maybe some one with CAD skills can provide a quick drawing of how to make these work, they really are the cats meow.



Yeah, some idea of how they work and how to use one is what I'm looking for.  Boca Bearings is where all my bearings came from, so I'll look there.

I gather the inside diameter has to match the shaft (1/4") and then the outside is what you spin.


----------



## Vietti (Feb 13, 2021)

Correct.  1/4" is a little small but will probably work.  Make an aluminum pot to press the clutch into and on the other end insert a steel shaft to hold in the drill.  Be careful to get rotation correct before pressing in the bearing.


----------



## Brian Rupnow (Feb 13, 2021)

Bob---I posted a thread and drawings for a starter spud like the one I use in my variable speed drill to start my engines. It was in a post tiled "Gentlemen, start your engines" a few years ago. Now I can't find it. If anybody can find the link, please put it up for Bob.---Brian


----------



## coulsea (Feb 13, 2021)

This is what I use. to get the curved holes I drill the main hole (6mm) 6mm in from the end which will leave 3mm of metal between it and the end, then with a 6mm round file, file down from half a hole to the side of the first one and when it breaks in to the first one it will naturally take the path of least resistance and work its way in to the first hole.


----------



## CFLBob (Feb 13, 2021)

Brian Rupnow said:


> Bob---I posted a thread and drawings for a starter spud like the one I use in my variable speed drill to start my engines. It was in a post tiled "Gentlemen, start your engines" a few years ago. Now I can't find it. If anybody can find the link, please put it up for Bob.---Brian



I have your drawings and started to make one this afternoon.


----------



## Brian Rupnow (Feb 13, 2021)

What Coulsea does looks nice, but it isn't really necessary with these little engines. A straight slot works fine. All of the old cars that came with a crank for use when the battery went dead were like Coulsea's. That was so that if the car started when you were cranking it, it wouldn't wrap you up in the crank---it would self-eject. When I was in high school I had a model A Ford with one spot on the flywheel  ring gear where the teeth were ripped off. If the engine stopped with that particular spot lined up with the starter, you would have to either push start it or use the crank.


----------



## CFLBob (Feb 16, 2021)

OK, got these done, now to test them.


----------



## awake (Feb 16, 2021)

It took me a minute to figure out why your piston looked so odd ... 

Then I realized it wasn't a piston, but rather a starting spud - right? Looks good, with one comment - make sure the pin is not too snug in the slot; you want it to be able to disengage easily, even when your drill may be at a bit of an angle.


----------



## CFLBob (Feb 16, 2021)

awake said:


> It took me a minute to figure out why your piston looked so odd ...
> 
> Then I realized it wasn't a piston, but rather a starting spud - right? Looks good, with one comment - make sure the pin is not too snug in the slot; you want it to be able to disengage easily, even when your drill may be at a bit of an angle.



Yes, it's a spud.  The slot is loose, that tool just falls out of it, I just have no experience with how loose it needs to be.


----------



## awake (Feb 16, 2021)

Based on your description, it should be fine!


----------



## Longboy (Feb 16, 2021)

You will find that if your slot is shaped as a one way clutch the drill will disengage smoothly when the engine starts. Image would have the angle on the back side left as hidden line.


----------

