Anyone remember seeing an article on a research engine that did not have a cam or valves? I think it had a shaft with holes in it, mounted in the heads that turned with the crank. The holes would line up with holes in the heads and allow for intake and exhaust. The only wear item was the seals for the holes.

I had a friend ask about and I can't find anything on it.

Thanks.

Coates engineering
Wall NJ

Thanks for the info.

Here is their site if anyone is interested in reading about them.



http://www.coatesengine.com/

They are right by me. They've been in the local paper many times over the years. I wonder why it never took off if it's such a great idea. It sure makes sense.

Very cool looking set up.

Jon

It's hard to match the opening rate/dwell/closing rate of conventional valve systems, so they don't breathe as well. Shame.

Such a simplistic design. One of those things that makes you wonder why no one ever thought of it.

Even if they don't breath as well, there certainly are applications where simplicity and reliability are worth the trade off.


Has anyone seen or heard one run???

Yeah.... on a tractor!.... Think about the servicability.... you can't "regrind" anything like that... you have to replace the entire "cam"... even if only one "lobe" is bad...

Some (2-stroke) go-kart engines (BM, Pirella, Komet, others) use the same principle, only with a rotating disc instead of a rotating sleeve. I think that it works OK in that application because it's less restrictive than sucking air through reeds.

I first saw a Kawasaki engine with a rotary valve in the lower case back in the Sixties... but they are getting only intake gasses... no hot exhaust.. plus the advantage of a rotary valve is asymetrical timing on the valve.. where as with a port ( non reed valve) the timing is symetrical.. two stroke technology took a step ahead with a movable "window" in the exhaust port to change the timing... ( yamaha TZ motorcycles)