Longboy's "FOREMAN" model gas engine.

[Longboy]

Thanks John. It is possible, without a lot of tooling and using the primary machine shop basics of a table top lathe and mill as I have, these straight forward 4 stroke designs can be fabricated by those without a journeyman's card or years of experience in a shop environment. I find it nice to occasionally fit in some uncommon features too.... like the drum style crank webs and location of the camshaft as done on FOREMAN. May some newbie's find this helpful and start on their 1st. single cylinder projects.
Dave

 

[Longboy]

Now with a tube muffler/ silencer, manipulating the carb mix & throttle settings on the Foreman engine to the stall threshold. Kinda looking for that old 4 cyl. farm tractor sound, a little reduced ignition timing and richer fuel mix at 1200 RPM about the best.


[ame]https://www.youtube.com/watch?v=qd-b2AezZj4[/ame]

 

[Parksy]

That's an awesome sounding engine! And it starts so easily. Nice work!!

 

[mnay]

Beautiful work and wonderful sound.
Is that your own design?
Keep them coming.

 

[Blogwitch]

Dave,

If I could make a suggestion to get your engine running as slowly as possible.
Fit the largest spoked cast iron flywheel into the space you have available. The extra peripheral weight will help to keep the engine turning over at the lowest possible speed, or else fit a steel or cast iron tyre onto the flywheel you already have on there.

That really is a wonderful piece of engineering.

John

 

[Longboy]

Thanks John....I'm aware that larger diameter flywheels with the bulk on its perimeter can slow an engine down. Perhaps I'll try that as a retro fit on some of my engines sometime.

 

[Longboy]

As per HMEM member Blogwitch suggestion, I didn't wait and made the heavier flywheel as I had brass stock in hand. This is a 1in. tall by 3in. diameter and is a little over twice the weight as the bronze flywheel. Only a half inch in dia. larger, it does the job and now the idle is in the 900RPM range,150- 200RPM less now. I can fit a 4in dia. piece on so maybe someday then for that!

[ame]https://www.youtube.com/watch?v=PQ5k24xsWrA[/ame]

 

[Brian Rupnow]

Very nice build!! I really like that "underhead" cam.--Brian