Rotor assemblies are made up of two parts – the rotor and a rotor gear. The gear is held in place by pins. I don’t have any personal experience in grenading an engine this way, but according to RB, if an engine is run above 8500 for extended periods of time the gear can move away from the rotor. Side clearance on a stock rotor is .005-inch, +/- .0005. The gear doesn't have to move very far before the rotor gets jammed into the side housing. At 13000 RPM the amount of damage should be spectacular.

Of course, these guys who claim to rev to such heights forgot to mention the race prepped rotors they have in their street cars. By race prepped I mean they must have pulled the rotors, removed the gear, machined a ring land into the rotor, machined a grove in the rotor gear, reassembled the rotor gear in the rotor, and used a snap ring to lock the rotor gear in place. Mazda did this with their race motors ages ago. I’ve heard of a set screw technique, but I’ve also heard that Mazda originally designed the assembly to allow some flex between the rotor and the rotor gear so as to reduce the amount of shock seen by the bearing and the stationary gears.

Aside from the engine seizing, there is the clutch assembly to consider. Ever seen whats left of a bell housing when a pressure plate comes apart? That’s not a problem when a flywheel explodes. That’s because there is no bell housing. Not much of a trans tunnel either. It doesn't have to be a total loss, if someone does this to an S5, I may be willing to buy some of the engine electronics.

 

Come on you guys... you dont even need a highly modified engine to rev your engine that high... All you have to do is pay a few hundred extra when you are getting your engine rebuilt and get it balanced along with the rest of your mods... then you wont have to worry about the "wobble effect," so you can hold your engine at higher rpms w/o as much worry... but whenever you hold the engine that high and strain it, it hurts it and you are taking some time off of its life... but it is up to the person how owns to decide how much fun the want to have at the expense of the motor.

 

Lol to all of those 13 -15k rpm people.. first off all all rx7's on stock ecu have rev limiters, may not be like the ones now a days that make the revs bounce once hit, but after 7800 on the 88 or turbo the engine wont mover, and I believe the limit on the s5 is at 8500 or 8800. And second of all, you should see the picks and videos from directfreak when his PP/clutch assembly blew up. The clutch and pressure plate destroyed the bell housing and rear plate cracked, and he is lucky that it didnt break through the cabin.

 

I think we should repo his car from him.

 

MARTIN you prity much said what I was going to say. over 8.5k your fly wheel stands a high risk of exsploding! you must have special fly wheels and clutch asseblys to do this and balanced trannys. If not the fly wheel will come apart and spray into the cab like a real gernade and kill you! second your rotors will smack into the housings and crush seals and cause more damage! You need a balnced motor for this rotors with machined clearance ignition and fule to keep up a scater shield installed and as I said fly wheel clutch and tranny. as well who knows if the rest fo the drive line can handle that let alone balanced drive shaft for 15k

 

not mines - and i stated the engine is a 12a. and i don't think it had an ecu cuz it was carb'ed but i could be wrong. i'll check and let you know when i get home (at work now). oh..it was a '83

 

A redline a day keeps the carbon away.

 

in a book about the wankel rotary engine...
the current rotary design that we have in our cars werent originally designed by felix wankel... his design didnt have an eccentric shaft...

this is the original true rotary engine....

"The chamber volume was 125 cc., best performance 29 hp (DIN) at 17000 rpm, engine diameter only about 260 mm, shaft offset 9,5 mm. Three spark plugs rotated with the inner rotor." - http://www.nsumotor.onlinehome.de/dkm.htm

 

Dr Felix Wankel conceived his idea of a rotary engine in 19241. In 1933, he applied for a patent for a DKM (Drehkolben Maschine or single-rotation engine), the first type of RCE. This type had the distinctive feature of an inner rotating housing and rotor moving in circular motion around a fixed central shaft"

By 1957 NSU had convinced Wankel to abandon the single rotation DKM design and all further research work was concentrated on the planetary rotation KKM type engine (Kreiskolbenmotor or planetary rotation motor )1. The outer rotor now became stationary and the inner rotor spun on an eccentric shaft8. This design proved to be easier to manufacture, cool, and maintain than the DKM1, and is the basis of the modern Wankel engine1.

http://technology.kingston.ac.uk/motorsport/rces.html