[all4bspinnin]

I have been reading the the pneumatic valves, rotary valves etc, and im trying to find a clear simple explanation of what exactly is going on...

any car guru's car to help...

thanks

[snorky]

Here's a good, brief, simple explanation of pneumatic valve return systems:
23 How do pneumatic valve return systems work ?

Some good diagrams here to give a good visual. they're old drawings from when they first started using pneumatic valves but they're still pertinent as their basic function remains the same: F1 Engines _ Valve technology


Electro hydraulic valves are said to be the future in F1 but I haven't any really good articles detailing them. all i've been able to find is very basic info.

[STidriver12]

hmm, so that pneumatic valves is similar to shock damper?
also its allow to rev more higher rpm like f1's engine that went over 10k rpm?

[all4bspinnin]

yea, they have all sorts of crazy stuff going on... i was researching it for an hour or so last night... i was able to find a few places, like the one posted above.... i have an understanding of whats happening... i guess i just need to read a little better...

[all4bspinnin]

And then,.... my favorite... the rotary valve... simple yet amazing...



The Coates Spherical Rotary Valve Engine is the most advanced in the world, with the most positive valving system ever built. 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.

[STidriver12]

Originally Posted by all4bspinnin

And then,.... my favorite... the rotary valve... simple yet amazing...



The Coates Spherical Rotary Valve Engine is the most advanced in the world, with the most positive valving system ever built. 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.

never heard of that kind of valve... but its awesome! wow

what if subaru use this rotary valve, there will be any improve powers as higher CFM?

[snorky]

Originally Posted by STidriver12

never heard of that kind of valve... but its awesome! wow

what if subaru use this rotary valve, there will be any improve powers as higher CFM?

from my understanding, it is expensive, difficult to tune, and currently has poor low speed (idling) characteristics similar to a high duration/lift cam.

[STidriver12]

Originally Posted by snorky

from my understanding, it is expensive, difficult to tune, and currently has poor low speed (idling) characteristics similar to a high duration/lift cam.

hmm sucks, but at least its still awesome valves

[mEnTaL]

I did some research on these Coates valves in college and according to my prof, Coates' claims are not backed up with facts and is considered a bit of a hack in the research community. At least to my understanding. It looks really cool though.

[all4bspinnin]

Originally Posted by snorky

from my understanding, it is expensive, difficult to tune, and currently has poor low speed (idling) characteristics similar to a high duration/lift cam.

Im going to email the company when i get home and see what they say about doing some heads on a boxer motor and possibly a forced injection version...

Btw, snorky... where did you get your info from?

[all4bspinnin]

here's some more info
http://home.people.net.au/~mrbdesign...utoTechBRV.pdf

[xlsupreme]

Originally Posted by mEnTaL

I did some research on these Coates valves in college and according to my prof, Coates' claims are not backed up with facts and is considered a bit of a hack in the research community. At least to my understanding. It looks really cool though.

yeppers. found the same thing to be true. It's not in production anywhere, and you won't find a car with it, even as a test bench. I wish it hadn't have flopped, it looks like a winner, but who knows...

[Neanderthal Racing]

Originally Posted by all4bspinnin

here's some more info
http://home.people.net.au/~mrbdesign...utoTechBRV.pdf

nice find.

[all4bspinnin]

Originally Posted by Neanderthal Racing

nice find.

interesting read huh...

i didnt think f1 banned new technology...