# Slave Valve arrangement for compressed air engines



## cfellows (Aug 20, 2009)

Since my slave valve assembly has come up from time to time with the different engines I've designed, I thought a bit of history and explanation might be in order. The attached drawing is only one of several variations I have come up with, but demonstrates the principle very well.

I originally came up with this arrangement while trying to design a Hit n Miss engine that would be powered by compressed air. That required that both inlet and exhaust valve operation be controlled with a governor through a single, cam operated pushrod. 

While the internal combustion hit n miss engines actuate the exhaust valve with the cam, my compressed air version uses the cam to actuate the inlet valve. And, while the IC hit n miss engine initiates a power stroke by allowing the exhaust valve to close, my engine initiates the power stroke by "allowing" the inlet valve to open. Other than that, the principle is the same. Without the governor, the engine will "fire" anytime the inlet valve is opened. This would normally be every other revolution if the cam is geared to rotate at half the crankshaft speed, but can also be made to fire on every revolution by simply mounting the cam directly on the crankshaft.







Chuck


----------



## putputman (Aug 20, 2009)

Excellent illustration and description Chuck. I can see how this might be used on any number of engines.

Are you still designing the compressed air version of the "Hoglet"?


----------



## cfellows (Aug 20, 2009)

putputman  said:
			
		

> Excellent illustration and description Chuck. I can see how this might be used on any number of engines.
> 
> Are you still designing the compressed air version of the "Hoglet"?



Thanks! I haven't gotten back to the compressed air Hoglet yet, but its on the agenda soon as I get a few of the new house honey-do's done.


----------



## cfellows (Aug 20, 2009)

Here is a video of the first hit n miss engine I built around my newly designed slave engine. However, I never completed the hit n miss version, opting instead, to run it in straight 4 stroke mode. As you can tell from the startup in the video, the poppet valve doesn't leak any air when closed

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

Chuck


----------



## deere_x475guy (Aug 20, 2009)

Thanks Chuck for the explanation. Nice job on getting that flywheel to run true......wish I could get mine to run that good.


----------



## ChooChooMike (Aug 21, 2009)

Boy, that's sure a good runner !!! :bow::bow::bow:

Mike


----------



## arnoldb (Aug 21, 2009)

VERY IMPRESSIVE Chuck Thm:
And one can clearly see it's running in 4-stroke mode from the video - slow "pop" sounds and twice as fast rotation on the crank 
A very smooth runner as well - will it go any slower ?

Regards, Arnold


----------

