Questions concerning Engine Head in relation to Engine Performance
Questions concerning Engine Head in relation to Engine Performance
(OP)
http://www.coatesengine.com/csrv.html
htt p://www.co atesengine .com/engin e_of_the_f uture.html
" 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"
"
is it possible to get that kind of engine performance just by changing engine heads? i would think that would require significant balancing of the crankshaft, and replacement of the pistons with lighter ones.
"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."
again, this seems too good to be true. i would think you would have to alter the timing and fuel.
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" 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"
"
is it possible to get that kind of engine performance just by changing engine heads? i would think that would require significant balancing of the crankshaft, and replacement of the pistons with lighter ones.
"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."
again, this seems too good to be true. i would think you would have to alter the timing and fuel.





RE: Questions concerning Engine Head in relation to Engine Performance
You have to pay very close attention to the balance of any engine at high rotational speeds. I don't think they're claiming that just any old five litre production engine will survive with just a head conversion. I'd assume the timing and fuel also has to be adjusted.
I can accept the high rotational speeds. What I wonder about is how they keep the 'cams' from warping from thermal stress, and contacting the concave sealing surfaces. I.e, after the 14,000 rpm dyno run, will it idle, or just seize?
Mike Halloran
Pembroke Pines, FL, USA
RE: Questions concerning Engine Head in relation to Engine Performance
Something here doesn't sound right.
"I love deadlines. I love the whooshing noise they make as they go past." Douglas Adams
RE: Questions concerning Engine Head in relation to Engine Performance
Please do a search of the site and save us the trouble of going through it all again.
I think the consensus was snake oil.
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RE: Questions concerning Engine Head in relation to Engine Performance
RE: Questions concerning Engine Head in relation to Engine Performance
Anyway at that rpm the recip loads would be a bit high.
Poppet valve float is a big limit to rpm limits. And also they are a bit restrictive to flow.
RE: Questions concerning Engine Head in relation to Engine Performance
do you think you would be able to run the engine that fast just be replacing the heads? i could maybe see an extra thousand rpm's. . . but not an extra 9000. let me know what you think.
RE: Questions concerning Engine Head in relation to Engine Performance
There will however be problems in other regards, not the least of which will be inertia loads from reciprocating parts and flame speeds..
The heat generated from the compression will in fact be more due to the extra VE and could induce detonation, but the hot spot on the exhaust valve will be reduced, thus reducing pre-ignition.
Regards
eng-tips, by professional engineers for professional engineers
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.
RE: Questions concerning Engine Head in relation to Engine Performance
http://www.eng-tips.com/viewthread.cfm?qid=53549
The bigger one evidently is gone.
This is obviously one of those inventions bought up by big oil, just like the 200 MPG carb.