Rotating Liner Engine

[usergone]

If you ask me about reducing valve train friction, I would say to go with a 2 cycle diesel. How about no valves?

Edit: they have exhaust valves, whoops

[Frank Lee]

The only 2 stroker diesel I'm familiar with (GMC) had valves AND ports and was supercharged.

[vtec-e]

Originally Posted by thecheese429

If you ask me about reducing valve train friction, I would say to go with a 2 cycle diesel. How about no valves?

How about this for reducing valve friction!
Welcome to Coates International Ltd.

Very little if any information on this outside of their website. I'd like to see how they manage to seal the valves without having issues like the rotary engines have with apex seals.

[usergone]

Frank, I stand corrected. I went and looked it up and, low and behold, they do have exhaust valves. Here's an article on it. It doesn't seem like it would be too hard to manufacture one with no exhaust valves (basically it would look just like your weed eater block/head) as long as it had enough boost.

Just imagine making one of these with a super-turbo charger (to get rid of the supercharger load at above idle) and some high performance lightweight pistons/connecting rods. Diesel with a 9k RPM redline!

[fud2468]

My dad bought a Willys 6 sedan new in 1931 and even in the 50's people still would ask him if it was a Willys-Knight (with sleeve-valve engine). His had a Continental Red Seal engine IIRC, but many Willys cars had the Knight engine, at extra cost. There was also a Stearns-Knight car and there may have been other makes that used the Knight engine.
The main advantage of these engines was that they were very quiet. Not sure why they would have been so great in aircraft though.
Ray Mac.

[some_other_dave]

Originally Posted by vtec-e

How about this for reducing valve friction!
Welcome to Coates International Ltd.

That's the rotary valve setup I was mentioning earlier. They've been around for perilously near 20 years that I know of, and have been "just about to enter production" for that whole time.

Last I heard (many years ago) they had significant sealing problems.

-soD

[ConnClark]

The Napier Deltic and Junkers Jumo didn't need valves and were quite efficient

Napier Deltic - Wikipedia, the free encyclopedia

Junkers Jumo 204 - Wikipedia, the free encyclopedia

[Frank Lee]

I've always been fascinated by the opposed piston configuration!

[ConnClark]

The coolest valveless engine was the Napier Nomad engines.

Napier Nomad - Wikipedia, the free encyclopedia

Part turbine and part diesel engine. The first version even had an after burner.

one also ran at 89psi of boost.

[vtec-e]

Boy did this thread go off on a tangent! Cool link to the napier nomad engine btw.
In relation to the rotating liner though. It's pretty much the only solution to the piston ring drag in an engine that i have seen. Ok, it's more complex but if built properly and by a japaneese company it would be pretty reliable im sure.
There are other losses in an engine too, valves being one of them. The coates system seems to be dead in the water due to sealing issues i suspect.

What are the friction losses like in the desmodromic system used in motorbikes? The lack of valve springs may help?

The diesel fuel pump is also a power hog. Could this be improved upon?

My thinking behind all this is that if a significant amount of fuel is used just turning the engine over, then thats where there should be most of the work done to lower fuel consumption.
Thats not to lessen the importance of good aerodynamics either. It all plays a part.

Ideas anyone?