Coates Rotary Valves

[SaabJohan]

Originally posted by Hudson
Valve float is eliminated with electro-magnetic valves. Formula 1 engines have used them and they run speeds much higher than you'll find in street cars. If you want to eliminate the traditional "valve" itself, that, too, can be done with an electro-magnetic system, again taking up less space than the system you're discussing.

This idea has been tossed around for decades. I know I've seen the design atleast ten years ago...and if I saw it then, it had to be around well before that time.

Nowhere on the site does it go into how the valves are lubricated. My money's on this engine either a) needing a lubrication system to work properly over the long haul or b) having such a gap (or wearing one away) that you would lose compression well before 50k miles. I know the site says that one prototype engine went over 150,000 miles, but until someone properly explains how you can have a low-tolerance moving part without any lubrication, I will not believe it.

Besides, since this idea's been around for over ten years, why hasn't it been put into production? Engineers are not "married" to the idea of the traditional engine design. They will, and have, taken dramatic steps in new directions when a better idea comes along. I don't think this is all you believe it to be.

F1 engines doesn't have electro-magnetic valves, they have a pneumatic valve train and they use camshafts (the pneumatics replace the valve springs since springs are too slow).
Electro-magnetic valves are today way too slow and takes too much power.

[hyc GTS]

I read a lot of the Well to Wire press releases, sounds like some very cool stuff.

I also wrote to Coates about developing their cylinder head for my Mazda KL engine (2.5L V6) and they said they had no applications available at this time (September 2001) and developing an initial prototype would cost around a half million dollars. And they said if I had the interest and financial backing to proceed further, they would be happy to talk about it. Sadly, as I haven't won the SuperLotto yet, I have not corresponded any further with them.

[454Casull]

Teflon on teflon (the lowest friction combination possible)

Nope. Molybdenum disulfide, a solid lubricant, has a lower coefficient of friction than any Teflon. NFC or Near Frictionless Carbon, a film coating, is currently the lowest-friction material in the world.

[454Casull]

And, IIRC, it can handle temps higher than 700C. So, if what I remember is true, NFC could very well replace motor oil as the main lubricant in engines in the future.

[hyc GTS]

Sounds incredibly slick. (sorry for the pun, couldn't resist.)

I wonder what else they can make with this stuff... It's a shoe-in for a Wankel rotary engine too if it can handle the combustion temperatures.

[454Casull]

Yup, the seals on a rotary would benefit from this.

And the kicker is, it's superhard, abrasion-wise. A coating of this on a sapphire (!) substrate survived 17.5 million passes against a steel ball, after which the testing machine failed. Upon inspection of the coating, the ball had left a barely visible track.

More? After coating, the stuff doesn't need secondary machining.

[hyc GTS]

All of the test results are for a pure nitrogen atmosphere, they mention that the friction increases in the presence of oxygen, water, etc. but they don't say by how much. Seems to be a critical omission.

[ivymike1031]

Originally posted by 454Casull
And, IIRC, it can handle temps higher than 700C. So, if what I remember is true, NFC could very well replace motor oil as the main lubricant in engines in the future.

It seems more likely to me that NFC will augment motor oil, and perhaps allow a reduction in the viscosity used.

[Shaw]

I read your notes about Molybdenum disulfide and I think it is something that our organization should be looking at. We are already producing the CSRV natural gas engine and if there are any ways of improving the performance, we would certainly be interested.

[Shaw]

Just wondering if any of you have seen the news release on the Coates engine & Porsche.??

Take a look:

http://www.finanznachrichten.de/nach...kel-868301.asp

[454Casull]

Forward progress is always a good thing.

[rich-h]

Its just a long shot but i was wondering if any of you guys new of any engineering papers which have been released on the topic or spherical rotary valve engines such as the cross and the coates design.

if not are there any interesting, articles or reports i could follow up to find out more. i am particularly interested in the sealing design for the combustion chamber and how the advances in new materials have helped.

thanks alot for any help, great forum keep up the good work. Rich-h

[claas900]

..Hello,i ran across this sight,doing a search on Coates Rotary Valve,and thought id give it a bump and see whats new?..

[public]

These post are all pretty old. I don't think much has come of it. I don't think you could get must flow through since a 4-cycle valve is closed most of the time, most of the rotating valve would need to be solid. Even when open it would spend a large part of the time only partially open??? What kind of flow would this allow?

[JD@af]

Originally Posted by public

These post are all pretty old. I don't think much has come of it. I don't think you could get must flow through since a 4-cycle valve is closed most of the time, most of the rotating valve would need to be solid. Even when open it would spend a large part of the time only partially open??? What kind of flow would this allow?

The following is directly taken from http://www.coatesengine.com/engine_of_the_future.html:

"The breathing capabilities of the system are almost double that of a poppet valve. For instance: a static test of a five-litre poppet valve engine on an airflow machine produced a reading of 133 cubic feet per minute (CFM) with valve fully opened. The five-litre Coates Spherical Rotary Valve Engine on the same machine, however, produced a reading of 319 CFMs fully opened; a colossal advantage in airflow comparison. A five-litre poppet vavle engine tested on a dynomometer under the same loads and conditions at 5500 produced 480 BHP and 454 foot pounds of torque. The maximum RPMs on the poppet valve engine were 5700 RPMs; the Spherical Rotary Valve Engine in comparison reached 14,850 RPM's, The Coates Spherical Rotary Valve comprises two spherical rotary valves assembled on two separate shafts - one for inlet and one for exhaust. They rotate on ceramic carbon bearing with no oil lubrication, the spheres do not make contact with any part of the housing. The seals are a floating type and are also made of a ceramic material. They have two piston rings and are floating in a small cylinder-type chamber, they are activated by the compression and the combustion strokes of the engine which allows 100 percent sealing effectiveness, when compressed.

Because the valves rotate away from the combustion chamber and are vented and charged on the opposite side of each sphere, this creates a lower combustion chamber temperature, allowing for higher compression ratios to be used thus creating an extremely efficient engine. Some of the Coates Spherical Rotary Combustion Engines are at 12 to 1, 13 to 1, 14 to 1 and 15 to 1 compression ratios depending on the application."