initial-rx7

alrite so iw as being stupid and doing doughnuts in a parking lot and accidently went 1500 over the redline. I talked to one of my friends dads and he told me rotary engines can rev over the redline and not do much damage to the engine due to the fact that obviously there is no pistons. I didnt really think this made much sense so i thought id ask you guys? I know this is really a noob question but i couldnt really find any information on the net so i thought id just ask.

TehMonkay

iTrader: (-1)

Youll be fine.

RB_eater

iTrader: (1)

Well going over the redline with a rotary probably isn't as bad a doing it with a conventionnal engine, due to the inherent smoothness of the rotaries. That being said, I often went WAY pass the redline in my truck without much consequence. I wouldn't recommend doing it but it shouldn't be too bad if only done once. It all depends on your luck I guess...

NCross

iTrader: (18)

ive hit 8k a couple times and it still runs fine.

are you saying you hit 9000 RPM?? s5's can take higher RPMS.

NOPR

theres the redline, then theres the rev limiter, which is about a 1000rpm or so higher (i think). unless its a first gen, then theres no rev limiter and you're on your own. basically, the engine will save itself before you get too carried away.

BklynRX7

Well as I understand it the reason pistons engines get damaged by over revving is because valves and other small parts are not totally attached to their location so moving them too fast can cause them to unseat and fall into the engine.

With a rotary there is much less to worry about, over revving can theoretically caused increased vibration due to the rotors, e-shaft and flywheels only being balanced to a certain speed.

That being said I have passed redline many many times with no consequence at worst hitting 9k on a missed shift.


Disclaimer: I have only stated my understanding of things while making no testimonial to their truth.

Rx7TyreBurna

iTrader: (1)

From what I understand, generally higher revs on a piston engine are achieved through improving the valve springs.

I think redline in a piston engine is when the car is getting close to where the valves start to "float". When they are moving so fast up and down, the springs can't keep up. Then they "float" for a moment, and in that brief moment, the piston can come up and smash into it.

From everything I have read, this is one of the main reasons.

teenwolf1393

ive heard from many people that a rotary will go higher and higher in the rpms till it eventually outrune the spark. i could be wrong tho

FCKing1995

iTrader: (3)

Piston engine cant rev that high due to a number of things. Mainly valve float caused by too weak of valve springs. Which allows the valve assembly to outrun the camshaft and to lose contact with the camshaft, meanwhile hitting the top of a piston (If its a high interferance engine). Another problem is if it has a timing belt and not a chain, and sometimes even with weak chains, it can stretch enough at high rpms to allow the same thing to occur as above. Lastly you get problems from the pistons and rods not being balanced well enough, or just too high of an rpm for the internal parts to handle without bending or putting extreme wear on the bearings and journals.

That being said... you have none of those parts. So shrug it off and go drive some more, you in all likelyhood have absolutely nothing to worry about.

RevinRx7

iTrader: (3)

86-87 Rev limits at about 8600
89-91 Rev limits at about 8800
You'll be fine. The ECU will not physically allow the engine to exceed this*. I forgot which the 7 cuts but its either fuel or ignition.
Don't do it a lot, or stay there for extended periods of time because it can cause accelerate wear much like someone said above. Its not balanced well enough to stay there that long and causes vibration within the motor, (you don't really make any power up there anyway)


*Unless you down shift into a low gear. Then its your speed that drives the motor.

NCross

iTrader: (18)

i dont think the stock fuel system/ignition is capable of hitting much higher RPM then the rev limit cuts at anyway. correct me if im wrong...

Red'vert

How high do rotaries go in max race configuration? Those Formula 1 pistonics are ridiculous...

VeLiduS

when im doing a burnout off the line i can rev the motor to 8k without it beeping at me until i start to take off more and the car has to push all the weight and ive asked around and i hear it also depends on the load on the motor. since no beep i guess it was ok to go to 8k while spinning the tires ? with this in mind i would imagine its capable of those revs but u prolly should go that high all the time?

pretty interesting, anyone have a similiar expierience ?

Spectator

iTrader: (1)

Going over the redline does not hurt the engine.

Hitting the cutoff will damage the engine at some point.

Rotary engines are lubricated by gas and oil at the same time. If there is no gas entering the combustion chamber (hits the fuel cut off ) and the engine still turns fast the housing and seals can get damaged.

Running lean with a rotary is already bad news, imagine at high rpms.

Red'vert

Through the rotary animation below I'm trying to fathom a rotary running at 9000 RPM spinning those rotors 150 times per second. Sheesh...

RX7freak08

questions isn't reving the engine at high rpms get rid of some of the carbon build up.

NCross

iTrader: (18)

the biggest problem of why a rotary engine blows is either detonation problems (ie, running too lean, boost creep) and heat.

Syncro

iTrader: (1)

At very high RPMs the E-shaft will flex and the proper clearance between the rotors and the housings goes kaput. If that's true then the apex seals also get put under much more strain. I think.

Don't rev the **** out of it for no reason, on a stock engine the stock ports are way choked and you're not making power up there anyways.