# My first I.C. engine, a variation on the theme of Webster



## JLeatherman (Nov 21, 2014)

I haven't done a lot of machining this year, but it's Christmas time again and I'm going to try and build my first I.C. engine for my Father's present.  Two years ago I built him a "Poppin" and he loved it.  I've decided to build something along the lines of a Webster, with a few changes such as:

Roller Rocker
Larger Flywheel with Spokes
Larger Cooling Fins and Fan
Viton Piston Ring

I have some questions as this build progresses.  I was going to post this earlier and get the questions out of the way, but I made myself wait until I had cut some metal (otherwise it's not "In Progress" yet).  Tonight I started on the rocker first.  I had some 932 bearing-bronze sheet left over from making a new gib for my lathe this year.  It's .030" shorter than the plans call for, but I can work around that and I'm not buying another piece.  I started by using a slitting saw to slice it close to width and then cleaned it up with an endmill.









Next I bored the center hole and at this point created my first piece of scrap by reading the wrong dimension off the print (the distance from the pushrod hole as opposed to the front edge of the rocker).  I had just enough bronze left for another part, and got the hole bored correctly so I could move on to profiling one side.





I flipped it over and profiled the other side, and the rocker is complete except for the tapped pushrod hole:





That's all for tonight.  Hope to get some more done this weekend.


----------



## Herbiev (Nov 22, 2014)

Following along with great interest


----------



## JLeatherman (Nov 23, 2014)

Got a bit more work done this evening.  Spent too much time figuring out where all my tools were, indicating in the rotary table and the chuck, etc.  I had a piece of 5"-diameter brass for the flywheel.  It was an end off of a drop and had a nasty saw-cut gouge on one side.  After facing both sides smooth on the lathe to see what I had to work with I then roughed out the relief on both sides on the mill.  Next time I'll chuck it up in the lathe and finish both sides and the rim, then it's back to the mill for the spokes.


----------



## dgjessing (Nov 24, 2014)

My first (and only, so far) IC engine was also a Webster - following with interest!

I also added cooling fins. I've been meaning to fit it with a proper carburetor from a model airplane engine.


----------



## JLeatherman (Nov 26, 2014)

It snowed here so I left work early and got some shop-time in.  Started by dialing-in the flywheel on the rotab again and after a few extra calculations drilling the pilot holes for the spokes.









After this disaster struck.  I picked out a brand new M.A. Ford carbide 1/4" end mill for machining the spoke cutouts.  It didn't have a weldon-flat so I put it in a collet.  I know you're not supposed to use an end mill in a collet, but I had drilled 3/16" pilots and it was only a 1/4" end mill (and super sharp) so I thought I'd be fine.  Incorrect.









On the very first hole the end mill instantly sucked itself into the part and out of the collet and shattered 

Fortunately it broke into large pieces, which I picked out with a dental pick.  I got another end mill (with a weldon-flat, in a proper end mill holder) and I carefully started over with the milling.  First I machined the outer edges:





The one side of each spoke:





The the other side of each spoke:





After this I used a collet to chuck up the nub I left on the finished side so I could machine the rim and the other side.





And here is the pretty much finished flywheel:





I'm glad to have that out of the way.


----------



## Cogsy (Nov 26, 2014)

The flywheel looks great, nice job. 

I've never heard not to use a collet for an endmill - it's all I've got to hold them. I googled it and I see the huge debate on the subject. As I've never had an issue doing it, I'm going keep using my collets!


----------



## jasonh (Nov 26, 2014)

I tried putting an endmill in a drill chuck once- and found at that it wasn't a good idea. I guess drill chucks aren't really built for radial loading. I hadn't heard that collets and endmills were bad- in fact I thought it was a good idea- at least I've never had a problem with it.


----------



## gus (Nov 27, 2014)

Drilling through brass and copper is very risky due to inherent tendency of snatching/grabbing.
Best to regrind rake to suit brass drilling. Drilling copper is even more deadly.Drill bit easily done on bench grinder. Socket was drilled through petrol tank w/o drill snatching. 

Congrats.The Flywheel was very well done.


----------



## JLeatherman (Nov 27, 2014)

Thanks Gus, this was my first attempt at a spoked flywheel and since the Webster plans don't call for spokes I had to kind of figure it out as I went along.  Modeling the whole engine and flywheel in SolidWorks was crucial for this as it let me play with all the variables.  The flywheel is 4 3/8" DIA instead of the spec'd 3 3/4" because I had this beautiful piece of 5" DIA brass and it seemed a shame to waste so much of it by going down to 3 3/4".

I didn't have much trouble with the drilling.  I've done negative-rake drillbits before for sheetmetal but I've never had issues like this in brass (although I can see why copper would be really bad).  Next time I'll drill all the way up to 1/4" before switching to the end mill.


----------



## Toolguy (Nov 27, 2014)

Carbide tipped wood router bits make good endmills for non ferrous metals. Their flutes are straight, or nearly so, and they don't tend to grab like the helix of a regular endmill. Also they have the greater back clearance required for a clean cut in soft materials. I use the 1/2" shank ones any time possible, they are a lot more rigid. A 1/4" shank works fine for a 1/4" cutter though. There are many shapes and sizes available and they are cheaper than the same carbide ones made for metal. 

TapMagic for aluminum is my cutting fluid of choice on all non ferrous metals. It works good for copper too. Hardly anything works on copper.


----------



## JLeatherman (Nov 27, 2014)

I started making the valves, then decided I should have the guides made first so I can check the stem fitment as I go.  Sorry, no in-progress pics.  These were pretty straightforward, although I did have to scrap the first one because I thought it was supposed to be .250" for the second diameter (should have been .3125").  Otherwise these were pretty simple, two setup parts.  The stem hole ended up a few thou off center of the tapered part, but since the stem bore and the seat bore were done in the same setup they should work fine.


----------



## JLeatherman (Dec 10, 2014)

Progress has been a little slow.  I've been mentoring a FIRST robotics team (middle school) and the last couple weekends they've been in my shop using the bridgeport (carefully supervised) to make some robot parts.  Also add to that the fact that I ruined my first two attempts at a crankshaft, and I'm a bit behind schedule.

I have learned a lot, however, and have finally made a really great crankshaft that I am very proud of.  Here's how I ruined the first two (although one wasn't my fault).  For the first one, I didn't want to waste a bunch of this nice 12L14 rod I have to I tried to machine the crankshaft out of it using the steady rest instead of cutting a blank and leaving extra for the chuck to grab on to:









Most of the way into the process the rod walked out of the chuck about 3/16" and buried itself in the tool at the shoulder.  Turns out the 7.5" Buck Adjust-Tru I got had been overtightened at some point in it's life and the jaws were sprung.  When tightened on the rod I could slip a piece of paper half way down each jaw!  That chuck is in the trash now (so to speak) and I'm using the 4-jaw usually mounted to my rotab until the backplate I bought from Enco arrives for my other Buck chuck (an 8" this time).

The second crankshaft machined well, but came out with about a .003" taper.  Although my tailstock was aligned well to the headstock, I had to extend it a good bit to clear the carriage when using the live center and I think it deflected slightly.  I corrected for this on the 3rd crankshaft by taking light cuts and then measuring the taper and adjusting the tailstock to compensate.  This crankshaft was made in the 4-jaw chuck with what was left of my 12L14.  I also turned a little spud at the end for a bit more clearance on the center before turning the main part of the crankshaft.





Here I've paused the machining to check for taper:





The finished 5/16" diameter:









After that I flipped it around and put it in a collet to machine the OD and face off the throw.









In the end it has about .0007" taper across 3" of length, which I'm fairly pleased with.  The bearings fit great.  I need to set it up in the dividing head now and bore the crankpin and then machine the throw to shape (although I'm tempted now to leave it as a full "disc").  Also, not sure you can see it, but there's a .090" radius where the shaft meets the throw for increased strength.

It's my first single-piece crankshaft, and although it took 3 tries (and a LOT of chips/scrap) I'm very happy with the final result.


----------



## JLeatherman (Dec 12, 2014)

Got my scrap rate down to 50%!  Made my valves this evening.  The first one actually turned out pretty well out of the gate, but when setting up for the 45* angle the cutter ended up cutting into the stem slightly for clearance.  I set up and tried again, backing out the clearance value (or so I thought) but it turns out I needed to back out double the previous clearance (diameter, not radius).  So the finished valve on the right has a significant undercut in the stem, and the one on the left has less undercut.  I could have used these, but I wanted to do the valves right so I made two more without any undercut at all.  Just need to lap them and drill the cross-hole for the keeper.


----------



## JLeatherman (Dec 20, 2014)

Made the cylinder tonight.  I've almost finished up what I consider the "difficult" parts of this engine.  Decided to make a bit more work for myself and I'm making this one hopper-cooled.  To that end I made a cylinder with no fins.  It's made from more 12L14, same as the crankshaft.  Started by turning all the rear OD's:





Flipped it around and put it in a collet to turn the 1.000" OD that goes into the head:





Afterwards, in the same setup, I bored it up to .874".  I left it .001" undersize so I could hone it.  The finish as-machined was actually quite good:





I picked up a set of hones for .75"-2" from an estate sale (the guy was a model engine builder).  Decided to try them out:





And here's the finished cylinder.  I tried repeatedly to take a good picture of the ID, but it wouldn't turn out quite bright enough.  Rest assured it is very smooth inside.  Should work great.









I did learn that I shouldn't leave the bore a full .001" to allow for honing.  It only took about .0002" to smooth it out, so it's a little undersize right now (about .8742").  Should be fine, I'll allow for it when I make the piston.


----------



## Brian Rupnow (Dec 21, 2014)

12L14 is notorious for rusting. Really bad rusting. I think you have chosen the wrong material for a hopper cooled cylinder.


----------



## bmac2 (Dec 21, 2014)

Hey Leatherman
Your Webster is coming along nicely and your machining is looking good. 
Personally I dont think you have to worry about rust on the cylinder. My Webster was my first crack at an IC engine and I finished it back in August (hate to gloat ;D but please see Project of the Month  September). Ive lost track of how many hours Ive put on it. Enough time to wear out and have to replace the bearing on the small end of the con rod.


----------



## bmac2 (Dec 21, 2014)

I used a cast iron cylinder and as of today cant see any signs of rust. All I do is after a run is tip it upside down and empty the water tank. The engine is still hot from running and any moisture left just evaporates. Every second run or so I give it a quick shot of WD40 just in case.


----------



## bmac2 (Dec 21, 2014)

The Webster is a beautiful design and very forgiving. Have fun with it and try new things. This is your engine. If you try something on a part and it doesnt work out . . . so what. Make a new one.  Ill be watching from the wings.Thm:


----------



## JLeatherman (Dec 22, 2014)

Thanks Brian and Bob.  I've watched builds from both of you with interest during my dry-spell in machining this year.  The 12L14 is all I had on hand in the necessary size.  I'll paint the OD where it passes through the water hopper and see what happens.  If it rusts up too badly I'll replace it later with something else.  I'm glad to learn things like this now, on the Webster bar-stock engine, before turning to several irreplaceable casting-based engines


----------



## gus (Dec 22, 2014)

bmac2 said:


> Hey Leatherman
> Your Webster is coming along nicely and your machining is looking good.
> Personally I dont think you have to worry about rust on the cylinder. My Webster was my first crack at an IC engine and I finished it back in August (hate to gloat ;D but please see Project of the Month  September). Ive lost track of how many hours Ive put on it. Enough time to wear out and have to replace the bearing on the small end of the con rod.



Hi Bob,

That was a great looking Webster. The Best.th_wav

Trust the weather is OK. Over here its raining almost everyday. Waiting for a good weather window of at least three day to go fishing.


----------



## bmac2 (Dec 22, 2014)

gus said:


> Hi Bob,
> 
> That was a great looking Webster. The Best.th_wav
> 
> Trust the weather is OK. Over here its raining almost everyday. Waiting for a good weather window of at least three day to go fishing.


Thanks Gus.
The Weather has been great. Above average temps in the 2 to 3C range, and just filled up at Costco for 74.9 a liter ;D. Not much for fishing around here if you dont have one of these. Oh, and a tent . . . and a thermos of coffee, ya, thats coffee .


----------



## bmac2 (Dec 22, 2014)

Leatherman I&#8217;ve seen some engine kits I'd love to build but I'm still too much of a hack at this with way too many mulligans. I&#8217;d need to find a kit that came with 2 or 3 of each part.Rof}


----------



## JLeatherman (Dec 24, 2014)

Got in some more shop time this evening.  Worked on the water hopper.  Started by turning a piece from my aluminum pile into a nice square/smooth blank as a starting point.





Started with the two stepped bores for the cylinder and the tapped mounting holes.









After that I hogged out the inside and after a few tweaks everything fit right in.













Although there is about 1/16" of radial clearance around the cylinder I'm concerned about trapping water underneath it after seeing it in place.  I'm considering machining a relief in the middle to permit water to move more easily between the top and bottom of the hopper?

Also, you can see the piston blank in these photos.  I machined it on the lathe in between passes of the fly-cutter when making the hopper blank.  It's just the right OD and is an excellent fit.  I also put the o-ring on for a trial and I'm a little concerned.  It seems too tight to me.  The o-ring is currently sized for ~10% squeeze, the same as some other members' engines.  I can get the piston/o-ring installed and can move it, but it is very snug.  I'll hope it breaks in a bit as a complete engine, or else when I lap the valves I may hit the cylinder with some lapping compound and see if I can make it even smoother (although it is quite smooth already).


----------



## Brian Rupnow (Dec 24, 2014)

1/16" radial clearance is all you need. There is no need for more radial clearance. I have at least 4 water cooled engines running with that radial clearance. As far as the o-ring squeeze goes--I use Viton o-rings (only one per piston). They measure 0.070" in cross section. I make the groove in my piston .057" deep, which is 81% of the ring cross section and that is about perfect on a 3/4" to 1" bore cylinder. I only use one ring per piston, as one is all you need to get a good seal, and two create too much drag.----Brian


----------



## JLeatherman (Dec 25, 2014)

Brian, it was on an earlier post of yours that I based my grooves.  Same dimensions, .057" deep by .096" wide groove, just one.  I'm hoping that when I get it on the engine with the connecting rod, which has much better leverage than my finger, that it won't feel so stiff.  Thanks for the confirmation on the water jacket clearance.


----------



## vederstein (Dec 26, 2014)

As a general rule, the nominal thickness of an AS568 or ISO 3601 (standard) oring is not the actual size of the oring.

A 0-series oring is nominally considered 1/16" thick.  Actually most of them (004 and above) are .070"  The 1/16" thickness is the depth of the oring groove for about a 10% oring compression which is often a good guide for dynamic (sliding) seals.

So you have the following:

0 series  - 1/16" nominal - .070 actual
1 series - 3/32" nominal - .103 actual
2 series - 1/8" nominal - .138 actual
3 series - 3/16" nominal - .210 actual

I design oring grooves all the time at my profession.  For reasons not important here, I have to violate the published groove dimensions very often.  Orings are very forgiving.

Also, the width of the groove isn't super critical.  You can go too narrow when there is no room for the ring to squeeze into.  You can go too wide (especially for dynamic seals) and the seal will roll in the groove.  But as long as you stay about 150% wider than the oring, you're usually in good shape.


...Ved.


----------



## JLeatherman (Dec 28, 2014)

Still working away on the Webster.  I've done a few easier parts that I didn't take pictures of (like the frame sides) but the tricky part I tackled today was the connecting rod.  Started by making a blank and boring the two holes.





I then took a scrap of aluminum and tapped holes for the conn-rod in two different orientations.  I also turned a pair of stainless bushings to bolt it down with.





A little roughing and it almost looks like a rod.





And the finished part.





I'm a bit surprised at how thin it looks around the main bushing end, but I suppose there are quite a few of these running and no one else has broken a rod?  If I get time I may try for one a bit thicker than the plans call for just for peace of mind...


----------



## JLeatherman (Dec 29, 2014)

Decided I definitely wasn't happy with the connecting rod so I took a crack at a redesign.  I left off the taper and went with my take on an "H-beam" rod:





Much happier with both the appearance, and the strength.  Now I can move on


----------



## Brian Rupnow (Dec 30, 2014)

That is a nice robust looking con rod. However, it is dramatic overkill for the Webster, and all the additional weight around the big end will do is throw the engine out of balance.---Brian


----------



## bmac2 (Dec 30, 2014)

Hi Leatherman
The connecting rod I made for my Webster, with the screws is probably around the same weight as yours and has a HUGE split bearing in the big end (dont know why I made it so big scratch.gif). This is a lot of mass to be tossing around if the engine is running at any speed.


----------



## bmac2 (Dec 30, 2014)

To compensate I made up some bolt on counter weights. These are simple to make so you can adjust the size/weight as needed. If you look on the internet you can find the formula for calculating the weight needed. Its something like half the con rod + piston + wrist pin  ½ your dogs age *2. The engine runs fairly smoothly and I dont have to threaten it with a nail gun to keep it from going walkabout.


----------



## petertha (Dec 30, 2014)

JLeatherman said:


> .. I left it .001" undersize so I could hone it.
> .. I picked up a set of hones for .75"-2" from an estate sale (the guy was a model engine builder).
> .. I did learn that I shouldn't leave the bore a full .001" to allow for honing. It only took about .0002" to smooth it out



I'm interested in that hone, can you tell me anything more about it? Is it a commercial set or did you mean the previous owner made it? What kind of stones does it require & what grit did you use? Assume you motored in the lathe or a drill with oil etc? About how much time before you achieved finish? Did you measure any resultant diameter change (meaning taper)?


----------



## petertha (Dec 30, 2014)

Brian Rupnow said:


> 12L14 is notorious for rusting. Really bad rusting. I think you have chosen the wrong material for a hopper cooled cylinder.



Brian, I've heard this too. Having said that, what are the options for 'water boiler engine' liners? I cant imagine CI would be much better, it would require stainless steel type ingredients, no? What were the FS engines using or how did they mitigate?


----------



## Brian Rupnow (Dec 30, 2014)

I don't profess to be an expert on boiler materials. I don't even know that much about 12L14.---It's just that I have seen numerous posts about how badly 12L14 rusts from exposure to humidity in the air inside a house or shop. I know that cast iron will rust, but it is popular for cylinders because of the graphite which makes up part of its metalurgical properties. I made my first hit and miss engine (the Kerzel) with a 316 stainless steel  cylinder and an aluminum piston, because I didn't want to look down the top of the water reservoir and see a rusty cylinder. I used a Viton o-ring on the piston, and never had a problem with differential expansion between the piston and cylinder. Later I made a Philip Duclos hit and miss engine with a cast iron cylinder, and although eventually it did rust on the exterior it never rusted badly enough to cause a problem. (I drain the water out of my engines when not using them). I really don't know how good a cylinder 12L14 will make in terms of wear properties, but if it rusts as badly as I have been warned about simply from humidity in the air, then it can't be good to have it immersed in water.---Brian


----------



## gus (Dec 31, 2014)

bmac2 said:


> To compensate I made up some bolt on counter weights. These are simple to make so you can adjust the size/weight as needed. If you look on the internet you can find the formula for calculating the weight needed. Its something like half the con rod + piston + wrist pin  ½ your dogs age *2. The engine runs fairly smoothly and I dont have to threaten it with a nail gun to keep it from going walkabout.



Hi Bob,

Planning to have a DIY MiniMagneto driven by the Webster I made 2012. Will
have the flywheel counter balance using your formula. Its true the Webster vibration nearly caused my Makita BandSaw to crash from work bench to the floor.
Happy New Year.


----------



## JLeatherman (Jan 27, 2015)

I kind of dropped off the radar for the last couple of weeks.  I got the engine about half mocked-up to be able to "give" it to my Dad on Christmas and then took it back to keep working.  Since then I've had to catch up on house work, and the FIRST robotics team I've been mentoring has had several competitions and required a lot of time and parts.

Starting back in I machined the cam.  The plans called for this to be made from steel and pressed onto the gear.  I'm building the engine to run a ball bearing roller on the rocker, so the cam doesn't need to be hardened.  I decided to try machining it right onto the boss on the gear.  First I made a mandrel to hold the gear, then I machined it on the rotary table:









Somewhere I messed up my calculations and the finished cam has less duration than called for (.175" instead of .250").  I'll give it a shot anyway, and if need be I'll machine it off later and make a cam separately like the plans called for.


----------



## Brian Rupnow (Jan 28, 2015)

A little random knowledge about cam shapes and cam followers.--The Webster engine, in it's original form, did not have a roller on the rocker arm. This means that the cam should have had a radius on the cam flanks (instead of flat sides). With flat sides on the cam, every time it revolves the flat side of the cam will "slap" the rocker arm. If the cam had a radiused flank, it would raise the rocker arm in a more gradual motion and not "slap" it. Cams with flat sides do work well with a "roller follower" because the roller can more closely follow the contour of the cam without getting "slapped" each time the cam revolves.--So, your plan for a bearing as a cam follower is a good one.--However--This bit of arcane science doesn't seem to matter to much with the Webster, because it is a low powered, low revving engine, and seems to work just fine as designed. I am sure that on higher powered, faster revving engines this effect of flat flanked cams as opposed to radius flanked cams makes a large difference to engine performance. I don't think the Webster really cares too much, and will perform well either way.


----------



## JLeatherman (Jan 28, 2015)

To address a few earlier points, here are pictures of the "mock-up" which is as far as I got in time for Christmas:













I did attempt a "balanced" crank to offset the rod weight and to attempt the keep the engine from walking around too much when running.  Got the carb adapter done and installed for an OS #10G model engine carb.  Still needs the cam finished, the top of the water hopper, a lot of miscellaneous spacers/bushings/hardware, the points I got didn't include the isolator that the wires mount to so I have to make something for that, and a fuel tank.


----------



## JLeatherman (Jan 28, 2015)

petertha, the hone was a commercial kit.  It came with 3 sizes of hones, each of which takes 2 sizes of stones, along with the various drives and such.  No idea if they're still in business, but there's a phone number on the lid.  Here are some pictures:


----------



## canadianhorsepower (Jan 28, 2015)

Brian Rupnow said:


> A little random knowledge about cam shapes and cam followers.--The Webster engine, in it's original form, did not have a roller on the rocker arm. This means that the cam should have had a radius on the cam flanks (instead of flat sides). With flat sides on the cam, every time it revolves the flat side of the cam will "slap" the rocker arm. If the cam had a radiused flank, it would raise the rocker arm in a more gradual motion and not "slap" it. Cams with flat sides do work well with a "roller follower" because the roller can more closely follow the contour of the cam without getting "slapped" each time the cam revolves.--So, your plan for a bearing as a cam follower is a good one.--However--This bit of arcane science doesn't seem to matter to much with the Webster, because it is a low powered, low revving engine, and seems to work just fine as designed. I am sure that on higher powered, faster revving engines this effect of flat flanked cams as opposed to radius flanked cams makes a large difference to engine performance. I don't think the Webster really cares too much, and will perform well either way.


 
Brian
How would you reac if every single time you would post something
you would have a NEGATIVE opinion on what you did:hDe:
Let him enjoy his build, I'm 100% sure if he needs help he will ask:fan:
JLeatherman go for it I'm watching, and enjoying


----------



## Brian Rupnow (Jan 28, 2015)

LUC---GET OFF MY CASE!!!  That was not a negative post. That was information given freely to someone who may not have known it. I  am getting very tired of you Luc, and of your attitude.---Brian


----------



## bmac2 (Jan 28, 2015)

JLeatherman said:


> To address a few earlier points, here are pictures of the "mock-up" which is as far as I got in time for Christmas:
> 
> I did attempt a "balanced" crank to offset the rod weight and to attempt the keep the engine from walking around too much when running.  Got the carb adapter done and installed for an OS #10G model engine carb.  Still needs the cam finished, the top of the water hopper, a lot of miscellaneous spacers/bushings/hardware, the points I got didn't include the isolator that the wires mount to so I have to make something for that, and a fuel tank.



JLeatherman !
That is one sweet looking Webster. Nice clean design . . . . Loving it. 
If I could respectfully make one point. 
In your mock-up. . . . . Wheres that beautiful FLYWHEEL!stickpoke


----------



## canadianhorsepower (Jan 28, 2015)

Brian Rupnow said:


> LUC---GET OFF MY CASE!!! That was not a negative post. That was information given freely to someone who may not have known it. I am getting very tired of you Luc, and of your attitude.---Brian


 

Hey did you take your AGRESSIVE PILL AGAIN
BTW I am entitle to my opinion like evryone else 
this is not
BRMEM 
but HMEM
cheers
and if their is something yuou don't like about my opinion
don't be mother Theresa send me a PM


----------



## gus (Jan 28, 2015)

No worry.The Webster is a very forgiving engine to build.


----------



## JLeatherman (Jan 29, 2015)

Although I found some of Brian's earlier comments on this thread a bit harsh and one-sided I thought the most recent post about roller cams to be informative.   In fact, upon further reflection I think my mistake in cam duration will help me because I didn't account for how the roller would impact cam timing. The roller should, I believe, lengthen cam timing slightly so the fact that I inadvertently shortened it when machining may well be a wash in the end.

I intend to continue building it as I want to, and look forward to the results. Anything that doesn't work as I'd hoped will just be time saved on a future engine.


----------



## JLeatherman (Jan 29, 2015)

bmac2 said:


> JLeatherman !
> That is one sweet looking Webster. Nice clean design . . . . Loving it.
> If I could respectfully make one point.
> In your mock-up. . . . . Wheres that beautiful FLYWHEEL!stickpoke



It's not pinned in place until i get the came done, and without it being pinned it slides back and forth into the cutout I made in the baseplate.  I don't want it getting dinged up.  Hopefully soon it will be installed for good!


----------



## JLeatherman (Feb 15, 2015)

It's been too cold to spend too much time in the shop at once, but I've gotten a bit more done.  I made the valve spring retainers, lapped the valves, and installed the valves and springs on the engine.  I made a change to the prints (again) in the spring retainers.  I counterbored the top side of each retainer so it fits over the pin the goes through the valve stem.  This will keep the pin in place, and it wasn't hardly any extra work.









I also finished tapping the rocker arm for the adjuster and installed it, and made a spacer to get the rocker arm directly under the valve.

Lastly I made the top cover for my water hopper.  It's not screwed down because I didn't have the correct length screws, but everything looks like it should line up.





Now that the rocker arm is in place I can make spacers for the cam and flywheel and get them installed.


----------



## Brian Rupnow (Feb 15, 2015)

It is very important to have the correct spring on the rocker arm to keep it in contact with the cam. I used a piece of recoil spring from a weed-eater.


----------



## bmac2 (Feb 16, 2015)

Morning JLeatherman
Its definitely been a weird winter, you guys out east both sides of the 49 parallel are having a bad one. Our normal daytime highs for this time of year should be around -12c with 2 or 3 feet of snow pack. This year its more like 0 to +6c and until the 20cm we got last week you could see the stubble sticking up through the snow in the fields. 
This Webster is looking sweet. Love the hopper and cover. Your valve block looks great. One thing that I read over and over before I built my Webster was people having trouble starting IC engines because the valves where leaking. What I did so I could test them was make up a block from scrap so that I could connect it to my compressor. I thought I had them seating but with 5 or 10 lbs of air going into the port that goes to the cylinder the whole thing leaked like a window screen.


----------



## bmac2 (Feb 16, 2015)

On my build I couldnt use a flat leaf spring like the plans called for because of the flare on the bottom of my frames. Id seen the way Chuck Fellows used trimmed down angle for the frame of his Bessemer Hot Tube Oil Field Engine and liked the look so much I just wanted to go with it not thinking of the spring.


----------



## bmac2 (Feb 16, 2015)

What I ended up doing was using a trigger spring on the rocker arm. Youve got straight sides so the flat spring it no problem and like Brian said any spring from a small recoil start will work. If you have a small engine repair shop near you ask if theyve got a broken one you have. Its surprising how many people are willing to help you out (talk to the oldest guy at the counter ;D) once they know what youre doing. Oh and put some pictures on your phone for show and tell. I think the only critical thing is It is very important to have *a spring* on the rocker arm to keep it in contact with the cam. The engine is coming along great and I cant wait for that smelling burning Coleman and giggling like a school girl moment.Thm:


----------



## gus (Feb 16, 2015)

Your spring is a very good idea. Bought flat spring from TokyuHands 2013. Was scrounging in Singapore to no avail but happened to holiday in Tokyo and found flat spring staring at me while shopping.


----------



## JLeatherman (Apr 15, 2015)

I'm still here and still working on the Webster when I have a chance. I had to modify a few small details in my plans. The cam roller retainer, which is basically just a small flanged nut, was supposed to have #4-40 threads inside but the walls were too thin and it kept breaking during threading. It now has #3-48 threads and works fine. I've worked on some of the fiddly parts, like the proper spacers for the rocker arm and cam, etc. Doesn't look like much more has happened, but the flywheel is on and some parts have been loctited in place hopefully to remain.

Here's a good shot of the overall engine to date:





And here's a shot of the finished roller-rocker:






I made a crank that uses a threaded crank-pin, which it now occurs to me should have been LH thread. I'm going to have to make the engine run backwards so that the forces on the crank make the pin tighter as opposed to unscrewing as it runs. Shouldn't be a big change. I'm up to the step where I drill and pin the flywheel in place, just giving myself a little time to be sure everything else is good first. Then I need to start thinking about securing it to a base and working on an ignition and fuel system.


----------



## bmac2 (Apr 17, 2015)

Leatherman what can I say . . . but . . . but . . . _DAMN_ thats a good looking engine.


----------

