Alright guys, so last night I downloaded the "best ever 787B video" found on this site, then went on with my curiousity to research a little about the 787B and its quad-rotor R26B, found out on wikipedia that one mazda engineerer stated that it can turn 930hp @ 10500 rpm, up from the normal 700hp@9000rpm found everywhere else, well first question is, is it possible for the R26B to make over 230+ps per ROTOR!? if it did, no wonder it won the race in 1991 :worship:

So then my curiousity drives me further to google up the highest revving rotary engine, and then i found this thread on rx7club.com

Some states that it can go up to 11000rpm with some modifications, some says 14000, some even stats 18000, and thats F1 terriority

http://www.rx7club.com/showthread.php?t=92289&highlight=13k+rpm

I know its 7 pages long, so a little summery of it is that with some modication on a 13B, it can turn 11000rpm, but above that people on the board were calling BS, espeically teh 18000rpm claim.

So guys with rotary knowledge here, just how fast can a rotary turn, and I am not talking about stock block, but its always good to share with others highest rpm you have seen on stock rotaries as well=D

I've always thought that rotaries have a very very high redline learned from the RX-8, but it saddens me to think that Spoon made their S2000 to go 14000rpm (got from the rx7club thread) but rotaries cant...... even if it can, i have never seen anyone able to prove it... Also not to mention F1 boingers with 18000redline

I know that there is a possiblity that this thread might turn into a "why go that high rpm" thread, but this is purely to satisfy my curiousity, and others that might wanna know after seeing this, :) , thanks in advanced =D
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I'm far from being an expert, but I know the rotors themselves can handle very high rpm levels. The issue lies in the Eccentric Shaft flexing at higher speeds, and the accessory belts spinning the alternator and such to levels FAR beyond what they can probably handle. May be easier in a racing application with different equipment, but I dunno?

I had a 1 cylinder gas engine in my RC car that did 24,000rpm. Could you imagine if someone built a 1 cylinder engine to scale for automotive purposes.....that would be sweet.

I've always heard that the engine can theoretically rev as high as you want it too, the limiting factors are things like transmission. But i'm no expert.

YEah, i guess even if the engine can rev crazy high, not many transmision can handle it, mate it to a F1 gear box????

Hmm what about the R26B making 930hp?
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or gear down the transmission. Then you'll see a lot of torque :)

I had a friend who claimed he had a friend who had a 12A drag car with a heavily modded engine that did almost 20,000RPM. I didn't know any better at the time to claim BS, but suspect now it might be.

The Mazda guys at the dealer I prefer to go to have a lot of rotaries amongst their mechanics, and the manager told me that my RX7 (12A auto) with bridge/extend port work should happily rev to past 10,000RPM (and drink lots of fuel doing so).

A guy I used to work with had a 13,000 BP rotary. Never saw it in person, but I believe him when he tells me that's what it did.

F1 Engines are now revving beyond 22,000 RPM, but that was a test that Renault did on the new 2.4L V-8.

As far as the Revvs go, revving high is great as long as you are continuing to make more power. Most engines drop off at that high range. That engine in the 787B is truly an engineering masterpiece and I love the way it sounds. If it hadn't been outlawed it would still dominate today. I wish I still had the video of the Scoot 4 Rotor car engine being cranked over during a compression check. It's crazy to see the rotors as they pass the exhaust ports.

Just to add to the complete lack of expertice in this thread, I have heard that this: The issue lies in the Eccentric Shaft flexing at higher speedsis the first physical limiting factor on a high reving rotary. There is nothing supporting it in the middle, so if you hit a nice harmonic and the engine is spinning fast enough, your rotors start massaging the insides of your engine in ways that are not so nice.

Here it is.

http://www.epoch-net.ne.jp/yasu/777/4re_001_b.wmv

i borrowed (stole) an rx8 book off a master tech at work and the book discusses rev ranges on rotaries when they address piston vs rotary issues and the torque ranges of such....

and i quote

"A piston engine has a peak torque range. This means that the torque is available in a limited RPM range ( for example 4500-6000 RPM). A rotary engine has torque through its entire RPM range. If you do not have a rev limiter and redline, the engine could probably continue to rev just like a turbine. Race engines can approach 15,000+ RPM...."

there ya go!

F20C at 14000rpm, I don't think so even if its possible it would suck to drive in traffic or even idle

F20C at 14000rpm, I don't think so even if its possible it would suck to drive in traffic or even idle

It depends on how they ground the cams. If they kept the small cam near stock but went more aggressive with the big cam, the car would act almost stock below the switchover point but would be much more powerful at the top of its rev range. That's VTEC's big advantage over single cam profile valvtrains. Think of porting the 5th and 6th ports of the Renesis but leaving the other 4 alone...

there are a couple rx-7's in the "all motor" class in pro drag racing. I'd be curious to see how balanced they got their engines and what rpm they can hit easily

the highest I know of its some australian race engines that can take 14,000rpm and thats with a special scentric shaft.

I personally have rev race engines to 11,000 rpm for very short time without causing any damage

I had a 1 cylinder gas engine in my RC car that did 24,000rpm. Could you imagine if someone built a 1 cylinder engine to scale for automotive purposes.....that would be sweet.

OT, the engine in the TRAXXAS JATO is rumored to rev to the 30-40k range. My bro has one, and from the sound I believe it! Kinda hard to verify as there aren't a lot of dynos out there set up for a 2.5cc nitro engine ;)

I seem to remember reading about some of Felix Wankel's other rotaries (our engine is not his only rotary), and one of the earlier ones--a completely different design--could hit 25,000 RPM. The only trouble was, you had to disassemble the engine if you wanted to change the spark plug.

It depends on how they ground the cams. If they kept the small cam near stock but went more aggressive with the big cam, the car would act almost stock below the switchover point but would be much more powerful at the top of its rev range. That's VTEC's big advantage over single cam profile valvtrains. Think of porting the 5th and 6th ports of the Renesis but leaving the other 4 alone...

Possible but wouldn't it be a bit too peaky considering the stock is already so.

Possible but wouldn't it be a bit too peaky considering the stock is already so.

It would be for a street car, but if it's a track car you'd almost never come off the big cam (assuming it was done nicely) so it'd probably be fine. Definitely not a drag-friendly engine setup, though.

Here's a rotary engine that turns 18k RPM all day long. (http://www.osengines.com/engines/osmg1400.html)

I think this one wins the prize!!

http://www.me.berkeley.edu/mrcl/micro.html