Four Square Engine Plans

[vederstein]

This is a continuation of the "Un-Named Engine" thread. I've since actually named this thing "Four Square".

As promised, here's the plans.

I highly suggest you read up on the Un-Named Engine thread. This design requires significant air pressure to run because of the engine geometry. It can be greatly improved as demonstrated near the end of the thread. It does run, but expect to have 60-80 psi on this thing to run.

PDF Assembly drawings first.

 

[vederstein]

Now the individual part drawings:

 

[vederstein]

And finally the 3D cad file in Step format.

 

[vederstein]

Now some pictures of the final design and the obligatory video of the engine running:

 

[oldengineguy]

Interesting engine! What year is the T.D. in the background? Colin

 

[vederstein]

The TD is from '52.

 

[James Barker]

Ved', Thank you for sharing with us all here. Looks like a swell runner.

BC1
Jim

 

[vederstein]

I make some non-documented improvements to the engine. The most important change being that I went to smaller valve springs and added a screw such that I can adjust the spring compression. This allows adjustment of the spring pressure to just what's required to reliably keep the valves in contact with the cams.

I went from around 55-60 psi down to reliably idling at 25 psi: A Big Improvement!

Video, with comments below: