# A vertical single 4-stroke IC engine



## cfellows (Jul 24, 2013)

Although this engine shares some similarities with other vertical single engines, such as the Upshur and one built by Randall Cox, I'm calling this my own design since it has significant differences from the others.  It will be air cooled and have a bore and stroke of 7/8" x 1.25".  It will be throttled, not hit n miss.

I salvaged two vertical pieces I had from a previous project that never came to fruition (sound familiar?).   There were two 10-24 tapped holes in the top of each one and I had to make horizontal piece that fit across the top to fasten the two vertical pieces together.  Trying to drill holes in a top piece that align with threaded holes on the bottom part has never been a strong suit of mine.  

I first found a socket head cap screw that was the right length and thread size and mounted the threaded end in the 3 jaw chuck on my mini lathe.  Then I cleaned up the head of the screw so it was concentric with the threaded end.  After inserting the screw into the hole I wanted to match, I mounted the piece vertically in my milling vice, using a stop to precisely locate the edge from the side of the vice jaw.  I  then used a DTI to exactly center the screw head under the mill / drill spindle...







Then, I removed the vertical piece and inserted the blank top in the vice with matching back edge against the vice jaw and the end against the stop on the side so it was the same distance from the side of the vice jaw.  I repeated the process for each of the 4 screw holes and here is the result...






The result is as near perfect as I've ever achieved!


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## cfellows (Jul 26, 2013)

Been under the weather for the past week, so work has been a little slow.  I did, after 3 attempts get the crankshaft pretty much assembled.  I had tried to make it all one piece, but for what ever reason, I wasn't having much luck.  Probably just impatience.  I finally settled on a one piece throw and webs but am loctiting and pinning the main part of the shaft.






The cylinder turned out pretty good.  It's made from a single piece of cast iron, is 1.5" OD and about 2.375" tall.  Bore is .875".


























Before anybody jumps on me abut the screws holding the frame together, they are just temporary!   

Chuck


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## Brian Rupnow (Jul 26, 2013)

Chuck--As always, your work impresses me. It seems that after a bit of a drought, everyone is building engines now. Have fun, and good luck. I will be following.---Brian


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## cfellows (Jul 27, 2013)

Brian Rupnow said:


> Chuck--As always, your work impresses me. It seems that after a bit of a drought, everyone is building engines now. Have fun, and good luck. I will be following.---Brian



Thanks, Brian, you're a gentleman and a scholar!  

Chuck

PS:  ... and there aren't many of us left!


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## BronxFigs (Jul 27, 2013)

Mr. Fellows:

Looks like another very interesting build/tutorial.  Good luck with the rest.


Frank


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## Brian Rupnow (Jul 27, 2013)

Chuck--Do you have a plan for a good throttled carburetor that you could share? I have 3 or 4 plans for hit and miss carburetors. and they all work reasonably well and they are all basically the same. I would like to build a good throttled carburetor to post as an alternate on the engine I have currently underway. My one venture into throttled carburetors which was essentially a hit and miss style carb with a globe style valve built into the air horn didn't work.---Brian


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## Cogsy (Jul 27, 2013)

Looking great, I'll be following along.


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## cfellows (Jul 27, 2013)

Brian Rupnow said:


> Chuck--Do you have a plan for a good throttled carburetor that you could share? I have 3 or 4 plans for hit and miss carburetors. and they all work reasonably well and they are all basically the same. I would like to build a good throttled carburetor to post as an alternate on the engine I have currently underway. My one venture into throttled carburetors which was essentially a hit and miss style carb with a globe style valve built into the air horn didn't work.---Brian



No, sorry, Brian, I really don't.  I have several drawings from other people, but I haven't tried to build one of them yet.  One is a Jerry Howell design and the other is from the late Bob Shores.  I plan to play around with some designs for this engine.  Maybe I'll come up with something...

Chuck


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## cfellows (Jul 29, 2013)

I got some more work done on the head today.  Here's the lash-up I used to shape the head..






I also drilled and tapped the spark plug hole as well.











Chuck


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## cfellows (Jul 31, 2013)

Got the valve cages made today.   They are brass and will be pressed into the head at some later point.






Chuck


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## Swifty (Jul 31, 2013)

Moving along nicely Chuck, will be watching this build as I want to design my own upright 4 stroke in the future.

Paul.


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## cfellows (Aug 7, 2013)

Swifty said:


> Moving along nicely Chuck, will be watching this build as I want to design my own upright 4 stroke in the future.
> 
> Paul.



Thanks, Paul.

For the past few weeks I've been distracted by my new membership at the local TechShop.  Currently, their 3D printer has me absolutely captivated, to the point where I'm starting to plan for building my own.

Despite all that, I did manage to get back out in the shop today.  I made the timing gears...






I'm going to have to make another pass on the large gear.  The teeth are a little too fat and I'm not sure why..

Chuck


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## cfellows (Aug 8, 2013)

When drilling matching holes between two parts, experience has taught me that I will get the best results by drilling both parts at the same time.  When I'm unable to do that, the next best thing is to make a drilling guide which can be located on each part pretty precisely and drill through the holes in the guide into the part.  So, here is the drilling guide I made and the two parts in question.
















These will be 3-48 SHCS.  I would like to have used something a little bigger, but the flange width on the cylinder base won't accommodate a larger head.  One of those cases of design as you go...  :headscratch:

Chuck


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## cfellows (Aug 12, 2013)

Got the camshaft pretty well finished today.  I started with a piece of 1/2" cold rolled steel, 5/8" long.  I turned the space between the lobes down to 1/4".  The lobes are each 3/16" wide.  In the lathe,  I bored a 3/16" hole through the center, then loctited and pinned the spool to a piece of 3/16" drill rod.






Next, I mounted the piece vertically in my rotary table and used a boring head with the cutter facing inward to form the lobes.  The cutter was set to turn on a circle about 1.25" diameter so it would remove an arc as it swept by the lobe.  Each time after plunging the cutter through the thickness of the lobe, I turned the crank on the rotary table one turn, advancing the lobe 1/72 of a turn.  I continued this all the way around until I had the lobe pointed like I wanted.  Then I flipped the cam assembly over and did the other lobe with the point rotated 90 degrees from the first lobe.  






And here's what it looks like in the engine.











Chuck


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## Brian Rupnow (Aug 12, 2013)

Very nice Chuck. I'm still following.---Brian


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## kadora (Aug 13, 2013)

Chuck i like your threads because they are perfectly illustrated
and detailed .
This is why i would like to ask you if you could start new thread
on building your own 3D printer. 
Thank you


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## cfellows (Aug 13, 2013)

kadora said:


> Chuck i like your threads because they are perfectly illustrated
> and detailed .
> This is why i would like to ask you if you could start new thread
> on building your own 3D printer.
> Thank you



Thanks, Kadora.  Not sure how the moderators would feel about a build thread for a 3D printer.  Might have to start a blog somewhere about it.

Chuck


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## ShedBoy (Aug 14, 2013)

Looks good Chuck.

Brock


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## cfellows (Sep 12, 2013)

Got the connecting rod finished and the piston mostly finished today.











After I finished up the piston, I'll get started on the valves, rocker arms, etc.

Chuck


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## canadianhorsepower (Sep 12, 2013)

great work Chuck

how do you manage to put text in between pictures on the same posting

thanks

Luc


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## cfellows (Sep 13, 2013)

canadianhorsepower said:


> great work Chuck
> 
> how do you manage to put text in between pictures on the same posting
> 
> ...



Thanks, Luc.  To put text between pictures, I position the cursor at the end of the image line and hit the enter key which inserts a line after the image.

Chuck


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## cfellows (Oct 22, 2013)

Spent most of today working on a base for the engine.  Started with 1" x 1" angleh, 1/4" thick.  I cut part of one leg off, leaving about 1/8" proud of the other leg.  







I mounted each piece in the milling vice at 45 degrees off vertical.  Then used an end mill to cut the miter on each end.






Here's a look at the at the 4 pieces put together.  I still need to mill the top part flat...






Here's picture of two of the sides clamped to a piece of scrap aluminum.  The two sides will be welded together on the inside corner.






And here's a mock-up of what the base will look like.  The piece of 1/4" thick steel plate will be welded to the top of the 4 angle sides.






Tomorrow I should get it all welded together.

Chuck


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## vascon2196 (Oct 23, 2013)

Looking great Chuck....I'm sure it will be a great runner.


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## cfellows (Oct 23, 2013)

vascon2196 said:


> Looking great Chuck....I'm sure it will be a great runner.



Thanks, Chris.

Here is a picture of the finished base...




And here's a few pictures of the engine test assembled so far...




















Gotta add an idler gear for the timing gear train to the task list. 

 I'm not a big fan of the curved spoke flywheel.  Wish I had a nice 4 1/2" straight, 6-spoke flywheel with a thin rim.  I'll have to look around some..

Chuck


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## Swifty (Oct 23, 2013)

Looking really neat, love the base construction.

Paul.


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## cfellows (Oct 24, 2013)

Thanks, Paul!

 So I made another set of timing gears today.  Actually wound up making 2 sets (3rd altogether).  The first (second) set was too big.   :facepalm:






 I gotta say, I really love my Arduino powered dividing head.  It saves to much time and effort in gear cutting.  






 Just set the number of divisions, then press the step button to advance each tooth.






 Even keeps track of which tooth I'm on!

 Chuck


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## Brian Rupnow (Oct 24, 2013)

Neat indeed Chuck!!! Maybe I could borrow that to cut my 108 tooth gear----Brian


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## cfellows (Oct 24, 2013)

Brian Rupnow said:


> Neat indeed Chuck!!! Maybe I could borrow that to cut my 108 tooth gear----Brian



 Thanks, Brian. Why don't you build an Arduino Dividing Head.  Lots of fun and satisfaction!  Not that hard.

 Chuck


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## werowance (Oct 30, 2013)

i reall like the base. did you also weld on the outside seams and smoothe back out or is the tolerence just that close that you cant see any gaps in the corners where the angle iron comes together in a 45deg. ?

i also really like the engin design. cant wait to see more progress.


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## cfellows (Oct 30, 2013)

werowance said:


> i reall like the base. did you also weld on the outside seams and smoothe back out or is the tolerence just that close that you cant see any gaps in the corners where the angle iron comes together in a 45deg. ?
> 
> i also really like the engin design. cant wait to see more progress.


 
 All the welding is done on the inside, none on the outside.  By squaring up the angle first, then carefully mounting at 45 degrees in the milling vice, I was able to get the angles cut pretty accurately.

 Waiting on flywheels from Martin Model at the moment.  Also working on about half a dozen projects all at once.  Hard to stay focused!

 Chuck


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## gus (Oct 31, 2013)

HI Chuck,

Looks like another great engine from a Maestro. Will be following this thread.


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## cfellows (Nov 2, 2013)

Thanks, Gus.

 My flywheels from Martin Model came in the mail yesterday so today I got them machined up.  Had to remove quite a bit of metal to get past some unevenness in the castings, but they turned out good I think.






 Chuck


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## Davewild (Nov 3, 2013)

Very nice Chuck, I'm following along.

Dave


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## cfellows (Nov 4, 2013)

Thanks, Dave!

 Got the valves finished today.






 Made from some 5/16" mystery steel I had on hand.  The steel was kind of gummy so they were miserable to get turned.  I used my tangential tool bit and had to keep it really sharp.






 Also got the springs installed and held in place with a cap and some e-clips.






 Chuck


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## gus (Nov 4, 2013)

Hi Chuck,
Would love to see this engine running.The flywheels look great.


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## cfellows (Nov 6, 2013)

gus said:


> Hi Chuck,
> Would love to see this engine running.The flywheels look great.



Thanks, Gus.  Hopefully I'm getting close!

 Yesterday I completed the support for the rocker arms.  Unfortunately I didn't take any pictures.  However, it is made from a piece of 5/16" square steel rod that I tried to gussy up some with some turning.

 Here's a few pictures of today's work.  This is the beginnings for one of the rocker arms.  It's 1" long x .280" high x .160" thick.






 Here I'm removing some stock off the bottom of each side to make it prettier and to make the whole assembly sit a bit lower on the head.






 And here they are with the bottom shaping done.






 Next I drilled and tapped the push rod end for a couple of 4-40 valve clearance adjustment screws.






 And here's a few pictures with the valve train in place...
















 Gotta install some setscrews in the flywheels, then it's on to the ignition parts and the carburetion.
 Chuck


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## vascon2196 (Nov 6, 2013)

Looking great Chuck...if you have plans for this engine I would love to put this on my bucket list. I'm also looking forward to seeing it run!


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## Swifty (Nov 6, 2013)

Looking very nice, your doing a great job.

Paul.


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## cfellows (Dec 20, 2013)

Thanks Chris, Paul.  Don't know if plans are in the cards or not.  I have good intentions, but follow thru is a little weak.

 I've pretty much finished the mill cnc conversion, so I'm back to work on this engine to try and get it finished up.  I made the mounting bracket for the ignition micro switch and also made a cam to trip it.  






 I will likely pretty up that bracket, removing as much stock as I can to make it look a little less bulky.  I plan to use a CD ignition system from S/S engineering.  I will borrow the unit from one of my other engines for the time being.

 I think the carburetion is the only thing remaining to get it running, so that will be my next project.   I've pretty much decided I want a throttled carburetor so am ruling out a vapor fuel tank for now.

 Chuck


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## cfellows (Dec 21, 2013)

So now the task getting the valves to seal begins.  Both are leaking despite what I thought was an extraordinary effort to get them true.  Sigh... :wall:

 Chuck


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## myrickman (Dec 21, 2013)

Nice looking build, Chuck! It is certainly shaping up nicely...and yes those six spokers look better than the other one. A bit of lapping on those valves should get them to seat right in. I too have always had to break out the compound no matter how carefully I machine the valves and seats. Apparently only a few tents makes all the difference in the world. Cannot wait to hear it run.


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## cfellows (Dec 29, 2013)

myrickman said:


> Nice looking build, Chuck! It is certainly shaping up nicely...and yes those six spokers look better than the other one. A bit of lapping on those valves should get them to seat right in. I too have always had to break out the compound no matter how carefully I machine the valves and seats. Apparently only a few tents makes all the difference in the world. Cannot wait to hear it run.



 Thanks!  Now that the holidays are behind me, maybe I can get this thing finished.

 I ran into the same problem that most people have with these little engines... I had no compression, the valves weren't sealing.  So, I reset the compound on my lathe to 45 degrees and did a skim cut on both the valves with a sharp carbide insert.  Then, I mounted this little jewel in the lathe.







 With the same compound setting, I dressed the back of this stone to match the valve edges (faces?).  The shank is 1/8" which is the same diameter as the valve stems.  I inserted the shank, in turn, into each of the valve seats and, pressing lightly against the stone with my thumb, I rotated it back and forth, lifting and moving it from time to time.  The valve seats were pretty thin, so it didn't take long to get a smooth, even grind all the way around.  I followed this by lapping in the valves with some diamond paste diluted with 3n1 oil.   I'm happy to say that the engine now has great compression, with no sign of leakage at all.

 Now it's on to the carburetor!

 Chuck


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## Brian Rupnow (Dec 29, 2013)

Chuck--Tell me more about the mounted point grinding tool please. What is it---Where did you get it--and how do you dress it?  As for carburetors----I have to admit, I have never built a "throttle-able" carburetor. All of my engines have simple hit and miss style carburetors except for the Atkinson and the Webster, which I have mounted throttle-able model airplane carburetors on. Are you going to build a throttle-able carb for your engine? This new engine I am working on, the opposed piston engine is not one that I would want to have revving very high, so I am going to have to do something other than a simple throttle-less carb.---Brian


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## cfellows (Dec 29, 2013)

Hey Brian,

 Unfortunately, I don't know where I got the stone.  I think it's just aluminum oxide, maybe 100 grit.  I used the same carbide insert I skimmed the valves with to dress it.  I think pretty much any grind stone would work as long as it's not too coarse.

 Chuck


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## Philjoe5 (Dec 29, 2013)

Chuck I apologize for chiming in so late but I sort of lost track of this thread.  About a week ago you mentioned your valves were leaking:



> Both are leaking despite what I thought was an extraordinary effort to get them true


How did you establish that?  Did you have "0" compression?

BTW, your twin flywheels look great.  I'm about to machine a pair just like that myself.

Cheers,
Phil


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## cfellows (Dec 29, 2013)

Phil,

I could hear the air leaking past the valves when I turned the engine over by hand.  And, I could tell both valves were leaking by alternately placing my finger over the intake and exhaust ports and seeing how that changed the sound.  Also, I could feel the pressure against my finger.

When the engine is sealed properly, you can flip the flywheel and the piston will go part way then bounce back from the compression.  If it doesn't bounce back smartly, you probably have a compression leak.

Brian, further to your comments, I haven't completely settled on a carburetor design.  The one you sent pictures of is a bit large and clunky for this engine.  I may have to try a new design of my own.

Chuck


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## gus (Dec 30, 2013)

Hi Chuck,

Happy New Year. Plan to build same vertical engine sometime.


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## cfellows (Dec 31, 2013)

gus said:


> Hi Chuck,
> 
> Happy New Year. Plan to build same vertical engine sometime.



 Thanks, Gus.  Happy New Year to you and the rest of the group!

 Here is a preliminary drawing of my design for a carburetor.






 Nothing particularly new or original here other than perhaps the idea of using a slitted collar for the air bleed adjustment.  Just ideas from lots of different carburetor plans I've seen.  

 It is going to be one of the smallest designs I've seen.  The main body will be made from 3/8" square brass bar.  The inlet and outlet ports will be 1/8" and the venture in the throttle barrel will funnel down to 3/32".  I've never tried using an air bleed hole before so I have high hopes for this feature.  The idea is to mix air in with the fuel before it reaches the jet, helping to atomize the fuel more and providing more air at idle.  I've used the slitted collar before on my vapor fuel tanks to adjust the main air mixture and it works well.

 The threaded shank on the throttle barrel was an idea I got from Bill Reichart's Panther Pup carburetor.  It will adjust the main jet needle valve as the throttle is opened and closed.

 Gonna get started on it today.  

 Chuck


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## Philjoe5 (Dec 31, 2013)

Thanks for the carby plans Chuck.  For my first IC engine I'm going the Ridder's vapor carb route.  Eventually I'll want a carb with better control so I'll be interested to see how your design works out

Cheers,
Phil


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## Brian Rupnow (Dec 31, 2013)

Chuck--I will be very interested to see how that turns out.---Brian


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## canadianhorsepower (Dec 31, 2013)

> The idea is to mix air in with the fuel before it reaches the jet, helping to atomize the fuel more and providing more air at idle


 
 Hi Chuck, 
 unless I'm missing something the air bleed hole is not at the right place......
 are your venturie tappered, and do you have the same size hole on both side of the needle???

 BTW how is your CNC mill working Nice workThm:Thm:


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## cfellows (Dec 31, 2013)

Thanks Brian, Phil.  

 Luc, you're right, that's not the typical place you see air bleed ports in model engine carbs.  I have seen at least 2 plans that have the port where I'm putting it.  I think the difference is that most model carbs have an air bypass which lets a small amount of air through when the throttle is completely closed.  In my design, the bleed air mixes with the fuel before it reaches the jet orifice.  This supposedly helps vaporization as well as providing an additional source of air when the throttle is closed. May not work as I hope, but it's worth a try.  I'd really like to come up with a simple design that works well on small engines.  This seems to be a pretty problematic part for many hobbyists.

 I started work today, making pieces from my drawings. I started with a piece of 3/8" square brass bar cut to a little over an inch long and drilling a 1/4" diameter cross hole for the throttle barrel.






 Next I turned down both ends, the outer end to 5/16" diameter and the engine side to 1/4" diameter.  It will be threaded with a model pipe taper thread and simply screw into the head.






 I flared the outboard end and also drilled a 1/8" through from end to end.











 Next I made the fuel inlet pipe which has the high speed jet at the top.  It also has a radially drilled air bleed hole going in through the flange.






 Here is a picture of the of the fuel inlet laying in place on the carburetor body.  In the finished carb, the inlet/jet will be soft soldered into the body.






 Here I'm starting on the cap which will be screwed to the top of the carburetor.  It will be threaded so that turning the throttle body to open or close the throttle will cause it to pull away from or move closer to the high speed jet, making the mixture richer or leaner.






 Sometimes making these small parts is easier if you start with a rather large piece of stock.  In this case, I'm using 5/8" square brass rod.  The finished piece ill be 5/8" long x 3/8" wide by about 3/16" thick.

 Next, I whittled down the sides to the piece is now 3/8" thick.  Used the MDI function in Mach3 for the first time today to control movement of the Z-Axis.  Love entering Z -0.032 and watching the end mill drop exactly .032".  I think I'm going to love this conversion.






 Here's the finished cap.  I left a 1/4" boss on the bottom of the cap to register the piece on the carb body.  After I drill and tap the mounting holes I will remove these boss and make it a flush fit with body.






 And the three pieces I finished today.






 Unfortunately, I need to remake the main body to increase the length a bit.  But, that went pretty fast and won't take long to make another one.

 Chuck


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## Philjoe5 (Jan 2, 2014)

Chuck,
I thought I had a set of points for the engine I'm building but they're not going to work easily.  In post 39 you're showing the breaker points for this engine.  Did you make those?

Cheers,
Phil


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## Brian Rupnow (Jan 2, 2014)

Philjoe--what he shows is a purchased micro switch.


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## Philjoe5 (Jan 2, 2014)

Chuck, Brian,

Where can I get one?

Cheers,
Phil


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## barnesrickw (Jan 2, 2014)

Thank you for putting something for scale in the pictures.


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## canadianhorsepower (Jan 2, 2014)

> Chuck, Brian,
> 
> Where can I get one?


 
 Radio shack or any electronic store


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## cfellows (Jan 2, 2014)

Philjoe5 said:


> Chuck, Brian,
> 
> Where can I get one?
> 
> ...


 
 I bought mine on Ebay.

 Chuck


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## cfellows (Jan 2, 2014)

Managed to pull my self out of my recliner today and do a bit more work on the carburetor.  I made a new body, drilled and tapped a few holes and made the throttle barrel. 






 I soldered the high speed jet in place and did a test assembly.











 Left todo:  Needle Valve, Air Bleed Adjustment Collar, Throttle Lever.

 Chuck


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## Philjoe5 (Jan 2, 2014)

Sorry to be a pain but will this work as a set of breaker points?

http://www.ebay.com/itm/TEMCo-HEAVY...109?pt=LH_DefaultDomain_0&hash=item5657c343bd

seems like it would be much easier to set up

Cheers,
Phil


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## cfellows (Jan 2, 2014)

That switch will work if you are using it with a low current transistorized  ignition circuit.  If you are using a standard ignition system with battery and coil, the microswitch won't handle the high current for very long.

 Chuck


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## Philjoe5 (Jan 2, 2014)

Thanks Chuck.  This electrical stuff is a Brave New World for me,

Cheers,
Phil


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## Brian Rupnow (Jan 3, 2014)

It should work fine for a CDI unit.


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## Brian Rupnow (Jan 3, 2014)

Chuck---I am REALLY curious to know how well that carb works!!!!


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## cfellows (Jan 3, 2014)

Brian Rupnow said:


> Chuck---I am REALLY curious to know how well that carb works!!!!


 
 Yeah, I'm kind of curious as well.

 Chuck


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## cfellows (Jan 6, 2014)

After reading through this thread:

http://www.modelenginemaker.com/index.php/topic,2842.0.html

 I've cleared up something that has confused me for some time.  There are apparently two different air bleeds in carburetor terms.  

 The idle air bleed talked about in model engine carburetors is really more of a bypass that provides a small, adjustable source of air directly into the intake only when the throttle is completely closed.  I believe this port is shut off as the throttle begins to open.  I don't really understand why this air bleed is necessary.  It seems to me the same result could be attained by just not closing the throttle as much.  

 The other air bleed is talked about more in full sized carburetors.  It is really an adjustable port which admits air into the needle jet chamber where it premixes with the fuel.  This mixture, which is controlled by the main jet needle, is then sucked into venturi where it further mixes with air from the carburetor air intake.  This air bleed supposedly helps atomize the fuel, but would also, it seems to me, have an affect on the main jet mixing adjustment.   I would also think the addition of this second type of air bleed might obviate the need for the first type if the throttle movement included a needle jet adjustment as well.

 The carburetor described in the link above has both types of air bleed adjustment in a rather elegant arrangement fitting into a small package.   It might worth trying this design to see how it works.

 Chuck


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## cfellows (Jan 7, 2014)

Luc,

I did more research on Google and it does look like what I'm calling the premix air bleed is more commonly known as an emulsion tube in full size carburetors. I'm guessing the 3rd adjustment you referred to is the main jet mixture.

I agree with you that trying to make minute adjustments to main the jet mixture automatically when opening or closing the throttle is a pain. I think I'm going to try an alternate design with the main needle valve below and away from venturi and forget about trying to integrate it with the throttle actions.

Chuck


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## cfellows (Jan 9, 2014)

I came up with a totally new carburetor design.  This one is extremely simple and easy to build.  I kind of went out of the box on a few of the features, but they seem to work well.  I've tried the carburetor out on my plumbing parts engine and so far I'm very pleased with the results.  It idles down nicely and will rev up to nice high RPM (well, high for this engine).  
 In this first picture, you can see the throttle adjustment.  It is nothing more than a 5/16" ID split sleeve that rotates on the boss on the back of the carburetor body.  The hole drilled into the side is the air inlet hole.







 In his next picture, you can see the air bleed or premix hole.  It is drilled all the way through to the center of the mixer tube just below the exit orifice that admits fuel into venturie.  The entire mixer tube can be rotated left or right slightly to offset the holes in the body and tube, adjusting the amount of air that gets admitted.  Different, I know, but it works well and probably won't have to be adjusted very often if at all, once tuned.






 Here's a shot from the top.  You can see that the mixer tube is an interference fit with the main air inlet.  It protrudes slightly into the main air chamber and forms a venture.  The fuel orifice is opposite and slightly above the premix or air bleed hole and faces into the air passage at a 90 degree angle. 






 Here is a video of the carburetor in operation on my plumbing parts engine.

 [ame]http://www.youtube.com/watch?v=UaY9ROZRUqE[/ame]

 I do have drawings for this but need to make some improvements to the throttle adjustment mechanism.

 Chuck


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## Philjoe5 (Jan 9, 2014)

Chuck,
Really great info for those of us new to the IC world.  Thanks for taking the time to post your work.  Anxiously waiting for your drawings.

Cheers,
Phil


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## Brian Rupnow (Jan 9, 2014)

Chuck--You may have just done an immense favour to all the model engine builders in the world. I look foreword to your drawings. The carb seems to work great on the engine in the video. I will use it on my opposed piston engine.---Brian


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## vascon2196 (Jan 9, 2014)

Hi Chuck,

I like the new carb...seems really simple. Sometimes thinking simple (and outside of the box) yields amazing results.

You tried to explain to me how your fuel mixer works back when I was building my Ford plumbing engine...once again, how does the fuel travel up the tube into the carb? Is it just vapor that is sucked into the carb when the piston retracts?

Just curious...I would love to use this design at some point.


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## cfellows (Jan 9, 2014)

Thanks, guys, I'm pretty excited about it. Chris, the fuel is just pulled up into the carb by the vacuum of the piston on intake stroke. One think I have found helpful in start the engine, is to place a plastic tube over the vent hole in the fuel tank vent hole and blow gently until the fuel level in the fuel line reaches the carburetor. Obviously this requires a vent hole and a transparent or translucent fuel line.

Attached is a PDF file with the drawing. Let me know if you see any issues. Also, here are a couple of pictures of the carb disassembled. the first picture shows the throttle hole side of the body.






And this shows the air bleed hole side.






I'll also post the plans in the upload section.

 By the way, if that brass fuel jet looks a bit worn, it's because I originally made it for my Odds n Ends hit n miss engine almost 20 years ago.  I converted that engine to a vapor fuel tank some years ago and this fuel jet and needle valve have been used in any number of carburetor attempts since.    It was originally designed by Phil Duclose and was used in many of his engines including the Six Cycle Odd Ball HitnMiss, the Whatzit oscillating IC engine, the vertical gearless hit n miss engine and the Topsy Turvey that I know of.  Mine is an exact copy, so if you have Phil's plans for any these engines, you also have plans for my fuel jet and needle valve.

Chuck 

View attachment Carburetor-Fellows.pdf


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## cfellows (Jan 10, 2014)

I wanted to add this 3d model of the carb body.  Note after you load it and click the activate button, you can rotate the view around by holding down the left mouse button while you drag it around.  Also, if go to the little PDF menu bar and click on the down arrow in the square with the little green and blue boxes, you can change the render mode to transparent.  This makes it easy to see where all the holes are and how they relate.

 Chuck 

View attachment Carb Body.pdf


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## vascon2196 (Jan 10, 2014)

Thank you Chuck...very simple.

I would like to try this on my plumbing engine...the gravity fed fuel drip is troublesome to maintain.


----------



## cfellows (Jan 10, 2014)

vascon2196 said:


> Thank you Chuck...very simple.
> 
> I would like to try this on my plumbing engine...the gravity fed fuel drip is troublesome to maintain.


 
 Yeah, I had read about that from some others, so that was one of the first departures I made from the Henry Ford design.  If your plumbing engine is much over a 1" bore, you might want to scale this carburetor up a bit, but, again, it might not be necessary.  

 Chuck


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## cfellows (Jan 10, 2014)

I started on another carburetor today.  This one will be for the vertical single and will be mounted on the fuel tank.  Here's a picture of what I have so far.






 And, yes, I'm using a pimiento jar for the fuel tank.  Clear so I can see the fuel level, no leaks, ideal as long as I don't drop it!






 The body is aluminum and I did make a new jet.  This one is a little different.  The 1/16" brass tube, which I found in my brass tubing spares box, has a .032" ID, so I just extended it all the way up into the jet tube and the needle valve will seat in it just a little below the orifice leading into the venturi.

 Chuck


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## barnesrickw (Jan 10, 2014)

ANYWAY, like the pimento jar fuel tank.


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## Brian Rupnow (Jan 11, 2014)

Chuck--I'm trying to model your new carburetor from your drawing, and in the left hand side of the drawing, top left corner you have the rectangular body dimensioned as 0.375" in one dimension and no width is given in the other direction. What width should it be?--Brian--


----------



## Brian Rupnow (Jan 11, 2014)

So Chuck--This is your carb in technicolour. Looks good!!! I will build it and use it on my opposed cyl engine.---Brian


----------



## cfellows (Jan 11, 2014)

Brian Rupnow said:


> Chuck--I'm trying to model your new carburetor from your drawing, and in the left hand side of the drawing, top left corner you have the rectangular body dimensioned as 0.375" in one dimension and no width is given in the other direction. What width should it be?--Brian--


 
 Brian, the missing dimension is 0.500".

 Thx...
 Chuck


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## Brian Rupnow (Jan 11, 2014)

That's what I had guessed at, thank you.


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## cfellows (Jan 11, 2014)

Continuing to evolve my design and maybe improve it. This is my fuel-tank-mounted version, but the change will work equally well on the first one I made.













I changed the throttle control to an 8-32 screw. As the photo shows, it screws in opposite the fuel orifice in the venturi. The advantages of this control are that it should be a lot less sensitive, since full closed to full open is achieved with 3 full turns of the screw. Also, as it closes, it will keep the air flow up next to the orifice which should improve the draw and the atomization. The 8-32 screw I used is just one I found in my spares drawer, don't have any idea where it came from originally.

As a note on how changes like this occur... when I was making the carb body, I inadvertently drilled the center chamber all the way through whereas my original design called for it stop about 1/32" from the outboard end. Rather than just plug it or make a new one, I started thinking about alternative throttle arrangements and came up with this one. Of course, I've yet to try it out, but I'm hopeful it will be better.

Chuck


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## Teza (Jan 11, 2014)

Hi Chuck,
To my way of thinking this last incarnation looks to be on the right track as the throttle should not adversely effect the fuel air ratio as it opens and closes, whereas the earlier design with the outboard throttle would greatly alter the mixture becoming very rich when it is closed, just my 2.5 cents (plus GST). Keep up the good work.
Cheers
Terry


----------



## cfellows (Jan 11, 2014)

Teza said:


> Hi Chuck,
> To my way of thinking this last incarnation looks to be on the right track as the throttle should not adversely effect the fuel air ratio as it opens and closes, whereas the earlier design with the outboard throttle would greatly alter the mixture becoming very rich when it is closed, just my 2.5 cents (plus GST). Keep up the good work.
> Cheers
> Terry


 
Yeah, Terry, I think, in theory you are right.  However, didn't seem to see that in actual operation.  Usually when the mixture get's too rich, especially at low speeds, the engine starts misfiring every other firing cycle.

I modified my earlier version of this carburetor to use the 8-32 screw for throttle control.  Here is a video of it running on my plumbing parts engine.

https://www.youtube.com/watch?v=N-7I_IjGlC8

Seems to work well.  Not quite sure why the engine continues to misfire somewhat regularly.  I've checked the spark and it never seems to miss a lick.  One issue with the Roy Sholl ignition system is using it with points, or in my case, a microswitch.  The ignition module is supposed to fire when the points break contact.  However, the circuit doesn't require much charge time and the "bounce" of the points can cause the ignition to (appear) to fire when they make contact.  I've actually got the engine timed to fire on the make, but on those occasions when the engine misfires, it may be sparking on the break instead of the make.  Might have to play with that some... oh, wait, I've got another engine to finish first!   :facepalm:

Chuck


----------



## kuhncw (Jan 12, 2014)

Hi Chuck,

I've been following your fuel mixer adventures.  Interesting and it sure runs well on your pipe fitting engine. 

Just to make sure I understand, the only path for the bleed air is directly into the fuel inlet/needle valve tube where it mixes with the fuel?  

Also, when you are running with the main air control pretty well open, does blocking the bleed hole cause any change in engine operation?

Regards,

Chuck


----------



## cfellows (Jan 13, 2014)

kuhncw said:


> Hi Chuck,
> 
> I've been following your fuel mixer adventures.  Interesting and it sure runs well on your pipe fitting engine.
> 
> ...



Hi Chuck,

Yes, to both questions.  When the engine is running flat out, putting my finger over the air bleed slows it down more than half way.  I haven't really played with the air bleed adjustment much.  I need to try playing with the two mixer adjustments and see how they affect one another.\

Chuck


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## Brian Rupnow (Jan 17, 2014)

Chuck--what's the latest carburetor news? I know you will come up with something incredible, and I don't want to build a carb which you have already "moved on" from because you have come up with something better. I thought the one you posted plans for seemed to work very good on your Henry Ford engine, but almost as soon as I modelled it, you were moving on to something else. I do have a model airplane carb I can use on my engine for its initial start up (That's assuming there is an initial start-up.) I am rapidly running out of things to make for my engine. About all I have to do now is put a keyway in the crankshaft and get those two arms in that the guy in Alabama is making for me.


----------



## cfellows (Jan 18, 2014)

Brian Rupnow said:


> Chuck--what's the latest carburetor news? I know you will come up with something incredible, and I don't want to build a carb which you have already "moved on" from because you have come up with something better. I thought the one you posted plans for seemed to work very good on your Henry Ford engine, but almost as soon as I modelled it, you were moving on to something else. I do have a model airplane carb I can use on my engine for its initial start up (That's assuming there is an initial start-up.) I am rapidly running out of things to make for my engine. About all I have to do now is put a keyway in the crankshaft and get those two arms in that the guy in Alabama is making for me.


 
 I've uploaded my latest drawings to the download section on this board and also over at MEM.  The only real departure from your modeled version is the throttle arrangement where I switched to an 8-32 screw throttle coming in from the side opposite the fuel jet.  I've also decided that the air bleed hole in my original design probably doesn't add any real value, so I leave it up to the builder whether they want to include it or not.

 Thx... Chuck


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## Brian Rupnow (Jan 19, 2014)

Chuck--Does this look about right to you? I didn't bother to model the spring on the #8-32 screw.


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## cfellows (Jan 19, 2014)

Brian, looks good except you have the vertical positioning of the fuel orifice and the air bleed holes reversed...






One other note is that the throttle screw needs to seat against the fuel jet when fully closed. I drilled the pilot hole with a #29 drill to the center of the venturi then finished tapping with a bottoming tap through to the opposite side of the venturi (with the fuel jet tube removed). Hope that's clear...

Chuck


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## Brian Rupnow (Jan 19, 2014)

Okay--Thanks Chuck---I have remodelled it and done away with the air bleed hole and lined the fuel jet hole up with the throttle screw . I have done as you suggested and tapped the throttle screw hole deep enough that I can screw the throttle screw right up tight against the fuel jet, but oddly it doesn't show up that way in the model.


----------



## cfellows (Jan 29, 2014)

Well, it runs!

 [ame]http://www.youtube.com/watch?v=d8unIoDOvQA[/ame]

 I've been held up trying to put the ignition together but today I thought I'd try it on a glow plug.  I think it's firing too early and needs to be retarded a bit, but I'll take care of the timing when I get the spark ignition finished.  

 Notice also, that it's running with my latest carburetor design mounted on the fuel tanke and a polyurethane tube connecting it to the engine.  That is a carb, by the way, not a vapor fuel tank!

 Chuck


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## Longboy (Jan 30, 2014)

Looks good and robust Chuck. Also enjoy the carb illustration done by Brian. Thanks, Dave


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## GailInNM (Jan 30, 2014)

Another runner!!!   
Congratulations Chuck.  It is a fine engine and can only get better with the new ignition and fine tuning.
Gail in NM


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## Swifty (Jan 30, 2014)

Looks and runs great Chuck, another one you can be proud of.

Paul.


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## Philjoe5 (Jan 30, 2014)

Nice work Chuck.  I'll be building one before long.  I know there were many iterations of it. Are the plans in the download section of January 18 the real deal?  Thanks very much

Cheers,
Phil


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## vascon2196 (Jan 30, 2014)

Great job Chuck...if and when I complete my current project, I would love to build this little guy. (or gal)...whatever gender it is!


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## Path (Jan 30, 2014)

Chuck,

Nice job ... looking forward to you next one.


Pat H


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## cfellows (Jan 30, 2014)

Thanks everybody, for the nice words. I always appreciate the encouragement.

Phil, if you are asking about the carburetor, yes, the plans in the download section are the latest version. I'm actually hoping to clean up the drawings for the engine and post those as well.

Today I started the cleaning up and finishing process. I installed the engine on the wooden base I had previously made.
















It's got a 3/4" Birch plywood top and the sides are made from Spalted Tamarind... sounds exotic, doesn't it? I had to install a new 3/16" thick plate on the bottom of the engine to provide hold-down bolt holes I could get to from the top side, rather than having to flip the base over. I also filed flats on the crankshaft for the timing gear and the flywheel set screws. The little black box is a battery case with a built in switch on top. It holds 3, AA cells and puts out 4.5 volts... Very handy! The Roy Sholl CDI unit will be mounted underneath the base.

I also installed a connecting rod that I had from earlier (don't ask why!) that is about 1/4" shorter. This lowered the compression ratio to probably around 4 to 1. It settled the engine right down, making it a lot less feisty! Much easier to start and idle down to a reasonably speed. It also doesn't jump all over the place now. I was able to start it and run it a few times after I got it all back together today and I really like the way it runs a lot better. I will definitely use a lower compression ratio on all future engines unless I'm really after performance.

Now I'm waiting on the arrival of some Futaba wiring connectors so I can get the electronic spark ignition installed.

Chuck


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## Philjoe5 (Jan 30, 2014)

Thanks Chuck for posting your build.  Someday I would like to give it a try.



> This lowered the compression ratio to probably around 4 to 1. It settled the engine right down, making it a lot less feisty!



That is a good thing to know.

Cheers,
Phil


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## gmac (Jan 31, 2014)

Thanks for the build posting Chuck! Any chance you could post a short video of the engine running with the lower compression for comparison, or is that what you've already posted?

It never fails that I learn a lot from your work - much appreciated.

Cheers Garry


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## cfellows (Jan 31, 2014)

gmac said:


> Thanks for the build posting Chuck! Any chance you could post a short video of the engine running with the lower compression for comparison, or is that what you've already posted?
> 
> It never fails that I learn a lot from your work - much appreciated.
> 
> Cheers Garry


 
 Thanks, Garry, I do plan to post another, longer video when I get the spark ignition installed.  The glow plug ignition seems a bit erratic, sometimes trying to run backwards when I try to start it.  Also, the vote is still out on how well the fuel tank mounted carb is working.

 Chuck


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## gus (Jan 31, 2014)

Hi Chuck,
I am now torn between building your engine and Nemetts-Lynx. Most likely build your open sided engine. I like the push rods and rocker arms. 
Please advise when plans are available. Great Engine.
Now in Tokyo shopping for Japanese hand tools and cutters. Its evident Gus been to TokyuHands.


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## cfellows (Feb 2, 2014)

You got it, Gus!  Might be a couple of weeks..

 As much as I'd rather be working on improving my carburetor, I realize I have to get the spark ignition installed on this engine.  I've been putting it off, probably my old, familiar fear-of-failure complex, but time to get serious.

 Here is the mounting for the hall effect sensor.  






 It started life as a piece of nylon (or maybe delrin) rod, 3/4" in diameter.  I cut off a 1/8" thick piece, drilled a 3/16" center hole for the camshaft to pass through and drilled and tapped a 2-56 hole to fasten it to the engine frame.  I also ground off the outside edges and cut a 070" deep slot to hold the sensor with a generous dollop of 5 minute clear epoxy.  Hopefully I can remove it after I've ruined the first sensor!   :facepalm:

 Entering unknown territory here, not at all confident that this will be an easy task!

 Chuck


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## cfellows (Feb 3, 2014)

I replaced the hall sensor today with a second, also new one. No joy! :'( So, I'm officially off hall sensors and back on standard, coil ignition. I got a set of points and cam installed today.




*

So, if any of you guys can recommend a low profile, small set of points to use in the future, I would love to hear about them..*

Here are the fixin's for my ignition box. 






It's pretty much the entire assembly as it powered my original, odds n ends, hit n miss engine. The coil is a vintage 1970's, unknown make motorcycle coil. The condenser is mounted on the back of the front plate behind the switch and there were only three wires connected to the engine: ground wire to frame, hot wire to points, and high tension wire to the spark plug. I plan to get the ignition box tidied up with a case for it tomorrow. We have company showing up any minute now, but if I have time later, I may go ahead and see if I can get it started since the ignition assembly is electrically ready to go.

Chuck


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## cfellows (Feb 3, 2014)

So here is a video of the engine running on spark ignition.  I haven't finished the ignition box, but I do have all the parts hooked up and operational.

[ame]http://www.youtube.com/watch?v=05Wa9mKA5Fg[/ame]

Still got some work to do on the carburetion, but the spark ignition is a decided improvement over the glow plug.

Chuck


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## Philjoe5 (Feb 3, 2014)

Very nice Chuck.  And running with the now famous Pimento Jar carby?

Cheers,
Phil


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## cfellows (Feb 4, 2014)

Thanks, Phil, yes, it is using a pimento jar for the fuel tank, but it is using a carburetor attached to the top of the tank, it's not a vapor fuel tank.

Chuck


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## Heffalump (Feb 4, 2014)

That's great Chuck! I love the sound


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## Brian Rupnow (Feb 4, 2014)

Chuck--Sounds great!!! Can you come up to Barrie and hold your thumb on my engine?---Maybe tame it down some for me?---Old Chuck magic thumb!!!


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## geoff p (Feb 4, 2014)

I could sit and watch that for hours.  Nice one Chuck.
Geoff
Thailand.


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## cfellows (Feb 11, 2014)

I've now built and tried 4 different variations of carburetors on this engine and am not really pleased with any of the results. The engine would run on all the carbs, but ran rough and wouldn't idle the way I wanted. I've decided to revisit some of the other parts of the engine as I think that's where some of my problems are. Most notable is the valve timing. I've always had a pretty simplistic view of cams and valve timing, figuring the intake and exhaust lobes should be 90 degrees apart, that the intake should open at top dead center and close at bottom center and the exhaust valve should open at or shortly before bottom dead center and close at or before top dead center. Well, folks, turns out it isn't quite that simple.

I found an article on valve timing and a series of 4 articles on cam grinding and design in my collection of Model Engine Builder. By the way, if you haven't looked through your issues of the magazine for a while, it's definitely worth revisiting. I've learned that articles in magazines don't generally coincide with what I'm working on at the moment and tend to get overlooked. It's amazing how many times I go back to older issues of magazines and find articles I had completely forgotten about or didn't even know I had. Anyway, the cam lobes should be separated by something closer to 105 degrees than 90 degrees. The intake should open from 10-25 degrees BTDC and close 40-60 ABDC. Think I'll choose 15 and 50, respectively. The exhaust valve should open from 40-60 BBDC and close 5-25 degrees BTDC. The overlap, when both valves are open, should be in the range of 10-40 degrees. A shorter overlap improves slow speed running, so I'm thinking 20 degree overlap should be good. I'm going to make the intake and exhaust lobes separately so I can adjust them independently.

By the way, I got the engine to run on Propane using two of my carburetor designs. I just removed the burner tip from my propane torch and connected it to the carburetor with a urethane tube. I had to fiddle with the propane torch control valve and the carb mixer, but I got the engine to run at least as well as it did on liquid fuel. Turns out you really don't need a demand valve as long as you don't leave the engine running unattended. But for now, the carb experiments are on hold until I get the valve timing and cam design sorted.

Chuck


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## cfellows (Feb 12, 2014)

I made new cams today.  The intake and exhaust cams are separate so their timing can be adjusted individually.  I started with 2 pieces of 1/2" drill rod, each 1/2" long and made these two spools.






 Next I drilled and tapped the set screws, then I cut the profiles on my milling machine.  I made a video and post the link once it finishes uploading to youtube.






 And here's what they will look like mounted on the 3/16" carrier rod to form the finished cam.






 Chuck


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## cfellows (Feb 12, 2014)

Here's a video of me cutting one of the cam profiles. It's kind of a long video, so you might want to skip the middle part.

[ame]http://www.youtube.com/watch?v=IEtqETL2LXs[/ame]

Chuck


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## Brian Rupnow (Feb 12, 2014)

Aesthetics aside, (yours look much cooler) do you really think there is a difference in performance between a cam with a flat flank like I build, and the ones with a convex flank like you have there on these small low speed engines??--Brian--- Holy cow--I just watched the video--Your chuck on the rotary table is moving all over the place while you are cutting!!!


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## Philjoe5 (Feb 12, 2014)

Chuck,
That's an approach I've never seen before.  It's clever and shows how useful the boring head can be...it's not just for boring.  I hardly ever think of it doing much more.

Cheers,
Phil


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## cfellows (Feb 12, 2014)

Brian Rupnow said:


> Aesthetics aside, (yours look much cooler) do you really think there is a difference in performance between a cam with a flat flank like I build, and the ones with a convex flank like you have there on these small low speed engines??--Brian--- Holy cow--I just watched the video--Your chuck on the rotary table is moving all over the place while you are cutting!!!


 
 Performance wise, your flat flank gives a much quicker rise and fall than the curved flank, which is good from a performance viewpoint.  However, it also puts more stress on parts since it's more like a hammer strike than a gradual lifting.

 Yeah, the rotary table has a little bit of play in it that I've not been able to get rid of.  I usually just use this rotary table for drilling so it's not a problem.

 Chuck


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## Walltoddj (Feb 13, 2014)

I've been following your post and thought this might help in HSM May/June 1990 the Panther Pup build pg 31 is the carb article looks pretty nice.

Todd


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## cfellows (Feb 13, 2014)

Walltoddj said:


> I've been following your post and thought this might help in HSM May/June 1990 the Panther Pup build pg 31 is the carb article looks pretty nice.
> 
> Todd


 
 Thanks, Todd, I had seen that and actually have built a close copy of it.  Haven't tried it out yet.

 Chuck


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## cfellows (Feb 15, 2014)

Here is yet another video as I continue looking for ways to improve carburetion for my engines.  Here I've got a quick and dirty set up to run propane.

[ame]http://www.youtube.com/watch?v=EbhF-mVQGO0[/ame]

Even with this crude set up it seems to be running better than anything I've achieved with liquid fuel.   Next I guess I'll start on a demand valve for it and maybe work on improving the mixer.

Chuck


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## Philjoe5 (Feb 15, 2014)

Excellent conversion there Chuck.  A good alternative to a conventional carburetor.

Cheers,
Phil


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## Brian Rupnow (Feb 15, 2014)

Good video Chuck. Every time I build and i.c. engine and have trouble with it flooding like crazy, I think I should be trying propane.--Brian


----------



## gus (Feb 16, 2014)

cfellows said:


> Here is yet another video as I continue looking for ways to improve carburetion for my engines.  Here I've got a quick and dirty set up to run propane.
> 
> http://www.youtube.com/watch?v=EbhF-mVQGO0
> 
> ...



I like the idling speed,she thumps away like the old WW2 Matchless. You hear every firing stroke and exhaust stroke. Almost like the Ruston single cylinder
engine running in the Heat Engine Lab,Singapore Polytechnic.


----------



## cfellows (Feb 16, 2014)

gus said:


> I like the idling speed,she thumps away like the old WW2 Matchless. You hear every firing stroke and exhaust stroke. Almost like the Ruston single cylinder
> engine running in the Heat Engine Lab,Singapore Polytechnic.



Thanks Brian, Phil.  Thanks, Gus, and your right, it does sound a bit like the old Matchless Singles. 

Here is still another video.  In this video, I'm using a commercial carburetor.  I don't know the manufacturer, but it has a venturi of about .21".  It has separate high speed and idle needle valves.  There is no air bleed, but the upper needle valve closes off the fuel as the throttle closes.

[ame]http://www.youtube.com/watch?v=JQ6MHgUQJeY[/ame]

The engine still doesn't idle quite like I want it to, but it's close.  I do plan to continue experimenting with propane and butane just to see what's possible.  Sorry for all the videos... hope you all aren't getting bored with them!  

Chuck


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## Philjoe5 (Feb 16, 2014)

> hope you all aren't getting bored with them



Never, keep 'em coming

Cheers,
Phil


----------



## cfellows (Feb 17, 2014)

One thing I've learned from the folks on this forum is that looks and attention to detail are important since many of our models will spend most of their time on a shelf being looked at.  And I'm usually one of the worst about getting it running then getting lazy about making it purty!

 So, with that in mind, I spent today working on (functional) aesthetics.  I had previously cut out a rectangular section on top of the wooden base to hold a small battery box.  Since I've decided to run it on spark ignition from a common ignition box, the battery was no longer in play.   So, I made a terminal strip out of plastic to fill the void and hold the connectors for the hot lead to the points and the ground wire.







I also made the brass terminals from 3/8" hex rod.






 And I made the knurled nuts from 3/8" round rod.  Here it is with all the engine wiring connected and ready to go.






 Next I'm working on completing the ignition box which will contain a 9v NICAD battery, a motorcycle coil, a condenser, and a switch.

 Chuck


----------



## Path (Feb 17, 2014)

And it just keeps getting better.th_wav


Pat H.


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## barnesrickw (Feb 17, 2014)

I'm not much of a make it pretty guy either.  Wish I was, but it's just not me. 


Sent from my iPad using Model Engines


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## cfellows (Mar 19, 2014)

I'm temporarily back to working on the Vertical Single 4 stroke engine.  Terry Mayhew, who is building the 18 cylinder radial engine, convinced me to give the hall sensor another try since he has had real good luck with them.  So, I built a test circuit, also designed by Terry and published in his 18 cylinder build thread.  Here is a short video describing the test circuit and showing it with the engine...

https://www.youtube.com/watch?v=oVHlDp2VKFE

I made a few substitutions to Terry's circuit.  Instead of a 2N2222 NPN transistor, I used a 2N3904 that I had on hand.  It won't carry near as much current, but is more than up to the 30 milliamps or so that this circuit is limited to.  I also used a 4.5 volt battery pack instead of 6 volts and I used a 150 ohm resistor instead of the 200 ohm he specified.

This test circuit lets me make sure the hall sensor is working and adjust the timing without the ignition circuit present.  This lessens the chance that I will damage the hall sensor during construction and testing, a problem that has plagued me in the past.  Terry has this circuit as a front end to the Roy Scholl ignition circuit and he has a switch in between which lets him use the test circuit without any power going to the ignition circuit.  I just use the test circuit by itself and will substitute the CDI ignition circuit when I'm ready to run the engine.

I also just finished up a new carburetor for the engine and as soon as I fabricate a fuel tank for it, I'll be ready to give it some test runs.

Chuck


----------



## Philjoe5 (Mar 19, 2014)

Chuck,
I see from the video you have elevated the fuel tank so that the top of it is about level with the centerline of the intake.  In my setup with Brian's carb, for which I had no success, the top of the fuel tank was about 3" below.  Could that be why I had no luck?  Thinking about it now, I'm sure I was expecting way too much vacuum?

Cheers,
Phil


----------



## cfellows (Mar 19, 2014)

Philjoe5 said:


> Chuck,
> I see from the video you have elevated the fuel tank so that the top of it is about level with the centerline of the intake.  In my setup with Brian's carb, for which I had no success, the top of the fuel tank was about 3" below.  Could that be why I had no luck?  Thinking about it now, I'm sure I was expecting way too much vacuum?
> 
> Cheers,
> Phil



Naw, Phil, that fuel tank is just sitting back there, not connected to anything.  But, I do like to position my fuel tanks so the top of the fuel level will be just below the bottom of the air intake when the tank is full.  The final arrangement of this engine will have the fuel tank attached to the bottom of the carburetor, so the maximum distance between the intake and the fuel level will be about 1 inch when tank is almost empty.  I will likely never fill the tank more than half full because of vibration so at that level, the top of the fuel will be about 1/2" below the air intake.

Chuck


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## Brian Rupnow (Mar 20, 2014)

Phil--I believe I told you that the top of the fuel should be about 3/4" from the center of the carburetor. 3" is way too much.---Brian


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## cfellows (Mar 21, 2014)

As I think I mentioned before, the timing gears on this engine are extremely noisy.  So, I've decided to try something different, not knowing if it will work satisfactorily or not.   I'm going to make new gears with the teeth cut on an angle.  Normally one would use helical cut gears and, while I can make helical gears, they are somewhat troublesome and I really wanted to know if simple, slant cut gears will work.   Here is the setup I'm using:






 I'm using my electronic dividing head, mounted in the milling vise at a 30 degree angle.  The gear pictured is the primary gear with 23 teeth.  If it looks OK when I finish, I'll go ahead and make the 46 tooth cam gear.  The teeth will have to be slanted in the opposite direction so the cutter will be positioned behind the gear whereas this one has the cutter in front of the gear.

 Stay tuned...
 Chuck


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## Brian Rupnow (Mar 21, 2014)

Chuck--I have to give you a big "Attaboy". You keep coming up with new things and machining operations that really impress me.---Brian


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## cfellows (Mar 21, 2014)

Brian Rupnow said:


> Chuck--I have to give you a big "Attaboy". You keep coming up with new things and machining operations that really impress me.---Brian


 
 Thanks, Brian, I'm always looking for an easier way to do things!  And I think this is going to work although it remains to be seen if the gears will be any quieter.

 Here is the finished primary gear.






 I reduced the angle to 20 degrees because I wanted to reduce the axial thrust forces between the two gears.  I also had to reduce the number of teeth from 23 to 22 in order to keep the pitch diameter close to the same as with straight cut teeth.  I had to use the helical gear formula for determining the tooth count/pitch diameter relationship.

 I think the gear looks fine so I will go ahead and make the cam gear which will have 44 teeth.

 Chuck


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## cfellows (Mar 22, 2014)

The good news is that the angle cut gears mesh properly and turn freely.  The bad news is there is no discernible difference in noise level.  I think the gear spacing is slightly too large, making the gears fairly loose.  So, now I'm going back to straight cut gears, but remaking only the larger gear somewhat larger.  Hopefully the tighter fit will overcome any mismatch in gear profile from the slightly larger size.

Chuck


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## cfellows (Mar 22, 2014)

Sigh....






 Pick your own subtitle:

 a.  Nobody said it was going to be easy.
b.  I've never had this much trouble before.
c.  Maybe that's enough practice...
d.  Wonder if there's a market for these things?

 BTW, one of the smaller gears pictured is OK and can be used... I think!

 Chuck


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## vascon2196 (Mar 22, 2014)

I think what you tried was great...helical gears are "supposed" to be quieter. Maybe just at high speeds? Either way I think its pretty cool that you did this. Keep on truckin'


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## Philjoe5 (Mar 22, 2014)

Chuck,
I have so been there.





Most of these are "serviceable" but not as good as they could be

Cheers,
Phil


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## Brian Rupnow (Mar 22, 2014)

If all else fails--cheat!! Put a little 600 grit lapping paste on the gears and run them for 2 or 3 minutes, then clean them up good. You have nothing to lose by doing this. and possibly something to gain.


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## cfellows (Mar 22, 2014)

Thanks, Guys.  

Brian, turns out the gears were too loose.  I don't think running them with grinding compound would have helped.

Chris, I think the angled gears I made were also too loose.  If they had been slightly bigger, I think they would have been quieter.

So, 7 or 8 gears later, I got it resolved.  Turns out the primary gear (23 teeth) was about .040" too small. If I had taken the time to measure the gears to begin with, I could have solved the problem with a whole lot less work!  I made a new primary gear and kept the original Cam gear (46 teeth).  It was just a tad too tight a fit so I applied some fine valve grinding compound to the gears and ran it with a drill for 5 or 10 minutes.  Then I removed the gears, gave them a good cleaning, oiled them and put it back together.  It's a whole lot quieter than it was and I think it will get even quieter as the gears wear against each other.

Here's a video I made today of it running...

[ame]http://youtu.be/cf8Vv8tWRCA[/ame]

I made a small brake which I can adjust with a screw to apply friction to the flywheel.  Later, I'll add a generator or some other respectable load to it.

Chuck


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## gus (Mar 23, 2014)

The defunct Leblonde Precision Lathe Plant,Singapore laps their gears before installing into gear box which again run for 72 hours and thereafter most of the lathe gear box run very quiet  They did encounter 3--5 percent of gear boxes that fail to meet max noise level and reworked.There are lapping gears sold for the purpose of lapping freshly cut gears. KG Gears,Japan sells Lapping Gears.

The two Lblonde Lathes I had ran very quiet compared to the Chinese,Taiwanese and some UK made.

For a gear box to run very quiet,box must be sealed and enclosed and heavy gear oil topped up.

Gus has no hands on experience lapping gears .


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## gus (Mar 23, 2014)

cfellows said:


> Thanks, Guys.
> 
> Brian, turns out the gears were too loose.  I don't think running them with grinding compound would have helped.
> 
> ...



Congrats, Chuck.

Great engine. Glad you solved and fixed the noisy gears.
 Are the flywheels counter-balance. Engine vibration seems to be minimal.

Your engine is on my build list.


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## cfellows (Mar 23, 2014)

gus said:


> Congrats, Chuck.
> 
> Great engine. Glad you solved and fixed the noisy gears.
> Are the flywheels counter-balance. Engine vibration seems to be minimal.
> ...


'

 Thanks, Gus, the flywheels are counter-balanced.

 Chuck


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## gus (Mar 24, 2014)

cfellows said:


> '
> 
> Thanks, Gus, the flywheels are counter-balanced.
> 
> Chuck




Hi Chuck,

My gaswork was right. Such a big mini single cylinder engine running at med speed and minmal vibration = counterbalance. 
Plan to counter balance the Webster by taking off the equivalent weight of piston and con-rod. Please advise would this do as a starting point.


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## cfellows (Mar 24, 2014)

gus said:


> Hi Chuck,
> 
> My gaswork was right. Such a big mini single cylinder engine running at med speed and minmal vibration = counterbalance.
> Plan to counter balance the Webster by taking off the equivalent weight of piston and con-rod. Please advise would this do as a starting point.



Gus, I'm not much of an authority on the dynamics of balancing an engine. The flywheels I bought from Martin Model just happened to have counter weights already cast in.

On my first Hit n Miss engine I didn't have any counterweights. So I started adding 1/2" diameter x 1/8" thick neodymium magnets on the inside of the flywheel rims opposite the crank throw. I think I started with 2 on each flywheel, then started the engine, then added another magnet to each flywheel, and started it. Finally, when I had 5 magnets on each flywheel, the engine seemed pretty well balanced. Here's a picture.







My plan was to remove the magnets, weigh them, then make counter weights out of brass or steel and permanently mount them on the flywheels with screws. But, I've never gotten around to it and the magnets have held really well. Of course, the outer rim of the flywheel helps hold the magnets in place.

Chuck


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## cfellows (Apr 20, 2014)

Although the friction brake was a simple addition for putting a load on the engine, it's not ideal.  Unfortunately, as the engine speed slows, the friction increases, so at low RPM's it becomes unpredictable.  If the engine misses a lick or slows a bit on its own, it will likely stop running, pretty abruptly.

 For a good engine load to keep the engine running smoothly at low RPM's what's needed is something that works like negative feedback.  That is, as the engine speed slows, the braking affect lessens.  I'm thinking a generator with an adjustable resistance might work better.  So, today, I made a pulley which attaches to one of the flywheels.






 When I get my polyflex belt, I will cut a 60 degree groove in the smaller diameter for the belt.

 I'm going to try a stepper motor for the generator.  






 It has 4 phases so I will probably hook up a bulb to each phase with a switch.  Then I can adjust the load by switching in more or fewer phases.

 Chuck


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## cfellows (Apr 22, 2014)

Today I made a mounting base for the Stepper (soon to be alternator).
















 If this functions well as a load for the engine, I'm thinking of making a case for the stepper that makes it look more like a vintage dynamo.  Seems like a good application for a 3D printer.

 Chuck


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## gus (Apr 22, 2014)

cfellows said:


> Gus, I'm not much of an authority on the dynamics of balancing an engine. The flywheels I bought from Martin Model just happened to have counter weights already cast in.
> 
> On my first Hit n Miss engine I didn't have any counterweights. So I started adding 1/2" diameter x 1/8" thick neodymium magnets on the inside of the flywheel rims opposite the crank throw. I think I started with 2 on each flywheel, then started the engine, then added another magnet to each flywheel, and started it. Finally, when I had 5 magnets on each flywheel, the engine seemed pretty well balanced. Here's a picture.
> 
> ...




Will monkey see/monkey do. Bought some magnets. No matter how many magnets put,I can only reduce the residue force to a minimum. Was working on big single stage,double acting(100--200hp) air compressor,boils down to a big&thick slab of concrete to absorb the residue force.


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## Brian Rupnow (Aug 10, 2014)

Chuck--a quick question. I see that you are running an open crank-case. What do you use for a bearing on the small end of the con rod, and how do you oil it?---Brian


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## cfellows (Aug 11, 2014)

Hey Brian,

 There is no bearing or bushing, just the aluminum rod running on the steel crankshaft.  It's fastened on with a rod cap in the standard fashion.  I just squirt a little oil on it now and then.  It also gets quite a bit of oil-like substance  that makes it's way past the piston and drips down the rod.  Seems to work OK.

 Chuck


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## Brian Rupnow (Aug 11, 2014)

Thanks Chuck


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