Smaller Horizontal IC Engine - 5/8" Bore

[cfellows]

About time to get started on another engine.  This will the smallest IC engine I've attempted with a 5/8" bore and 1.25" stroke.  I want this to be another slow running engine and I think this is about as small as I can go without it sounding like a weed whacker.



Didn't have a beer can for scale, so I had to fabricate one, 12oz by the way.  The cylinder will be made from cast iron.  I decided to go with air cooling because it's so much simpler than water cooling.  The flywheel is 5.5", which is quite large for this size engine, more like some of the really early Crosley and Daimler engines.  Hopefully this will let me attain the slower idle speeds I'm looking for.  The engine will be throttled using the simple carburetor I designed.  I'm going to try really hard to provide the drawings for parts as I go along.

I'm toying with the idea of trying this CAM setup instead of the traditional geared cam...



Chuck

[Kim]

That looks pretty fascinating Chuck!  I like the cam idea.  I'll definitely be following along! 
Kim

[b.lindsey]

Oh yeah....that cam set-up would add a lot of interest to it for sure as well as making it unique. Should be a nice project Chuck, but then again, all of yours are great to follow!!

Bill

[rudydubya]

Looks like another interesting build, Chuck, especially with that crossover cam on the flywheel.  Thanks for letting us tag along.

Regards,
Rudy

[Roger B]

5/8"=  ~16mm the same as my vertical engine. I will, as ever, be following with interest    The scroll cam will be interesting. Are you planning a suction controlled intake valve?

[cfellows]

Thanks, all, for following along.  Roger, the intake valve will be vacuum controlled.

Chuck

[ShopShoe]

Chuck,

Fantastic idea. I can't wait to see how you make the cam.

--ShopShoe

[cfellows]

Here's my first go at making a cam disk.  It's made of brass and the groove was cut with a 3/32" end mill.  I may have to go with a smaller groove, maybe 1/16", although even 3/32" is going to be tough to make a shuttle for.  I'm going to try to get the 3/32" to work.





Chuck

[b.lindsey]

Looks like that turned out well Chuck, would be interested in the process you used to machine it, especially if done manually. The groove do appear to be wider that the prototype photo you posted at the outset but I don't see why it won't work.

Bill

[cfellows]

Thanks, Bill.  I cheated and used CNC to cut it.  I first drew it up in Visio, saved it as a DXF file, processed it through CamBam, then machined it using a 3/32, 2 flute end mill.

Here is a photo of my second attempt at a shuttle, machined using CNC on the end of a 3/8" steel rod.  I had to file it down some to get it to ride the groove all the way round.



Preliminary results are promising although I'll need to lash it up in a functional assembly to see if it's going to work.  I think a thinner shuttle running in a thinner groove would follow better and I may have to resort to that but I'll try to get this one working first.

Chuck

[cfellows]

Two steps forward, 1 step back.  I shouldered down the back of the shuttle from 3/8" down to .156", parted it off, and was attempting to fit a small ball bearing race to the back, when it popped out of the vice on my work bench and, as you can probably guess, disappeared into that 4th dimension where all small parts are trying desperately to get to.  So, tomorrow, I get to start over on the shuttle.  Hopefully the next one will go smoother...

Chuck

[fumopuc]

Hi Chuck, I am following along here with big interest. That is a very extraordinary way to do the  timing of an engine.

[cfellows]

Thanks, Achim, wish I had invented it... 

Since I had to make a new cam follower I decided to modify the cam disk with a 1/16" groove instead of 3/32".   Since I had plenty of meat on it,  I mounted the cam in my lathe and faced off the 3/32" groove.  Then, using a 1/16" end mill, I milled a new groove along the same profile.



I did a bit more research on this cam style and discovered that I had the profile wrong on the follower I had made.  So, the new cam follower has a crescent shape rather than the eye shape.  I chucked the 3/8" rod with the cam follower shape on the end and prepared to neck down the back of it for a ball bearing race.



Then I parted it off and fitted the 5/32" ID ball bearing to the back of the cam follower.  Here is the follower with the bearing sitting in the groove on the cam disk.



I did a preliminary test by mounting the cam disk in my mini lathe and held the cam follower in my fingers as I spun the lathe over slowly.  It seems to track exactly as it's supposed to, so I'm pumped.  So, now I'll design he carrier for the cam follower and we'll see where that leads me.

Chuck

[Brian Rupnow]

Remarkable work Chuck.---brian

[Bearcar1]

Way cool Chuck    I'm watching from he cheap seats as this one unfolds…… great to see and hear of your endeavors.