TheBigOne

87 TII pre-cat rest is open exaust.
I get small back fires (de-acceleration) and once in a while real load KABOOM!!! (de-acceleration) backfire (rarely though).

Could a back fire (if extreme) cause your rotor to spin backwards?

If so what would be the end result?

Has this happened to anyone?

What happened after?

onepointone

i would assume it wouldnt spin much.. i mean, i would take the intake gasses, put it out the exhaust, then try to fire nothing

TheBigOne

bump

black_sunshine

Backfire cause reverse spin? not very likely, only on startup, with reversed leading/trailing coils and an almost dead battery/weak starter or extremely advanced timing. The way they're setup, it's extremely rare for a backfire to cause reverse spin, due to the fact, that when the compression stroke begins, the intake ports are covered, and the other rotor is forcing it to spin the correct way. Now, if you fug up and reverse the leading/trailing coils, your risk of backfire increases greatly, due to the fact that the leading coil sparks bolth plugs at the same time, and since you moved it to the "intake side" of the engine, well, you get the idea. Also, advancing your timing waaaaaaay too far will have the same effect, as will a mighty bad case of carbon-buildup.

Now, if by backfire, you mean those loud pops out of the exhaust, that's caused by a rich condition when decelerating (the stock computer sucks). The fuel ignites in the manifold/catalytic converter(s), causing a POP. Harmless to the engine for the most part, but don't expect your cats to last forever.

Thaniel

no.

1FastT2

iTrader: (1)

What your probally hearing is after burn rather than a back fire.

peejay

Hell ******* no.

TheBigOne

Ok well let me see how I can explain what Im trying to find out.



I drive on the freeway.

I hear whats sounds like backfire. And it probably is back fire.

Back to my original question.

What are the sounds and feel differences to detonation and back fire?

What does detonation sound and feel like?
What does backfire sound and feel like?

While driving on the road at freeway speeds and my car back fires could this cause a reverse spin on the engine?

Juan

iTrader: (28)

detonation sounds like someone hitting a small hammer on a piece of metal repeatedly. It makes a "ping" sound. I think it can also sound like popcorn popping. I dont know if you can feel it since Ive never had it happen on my car.

Backfire is a pop sound like a firecracker and if its big enough you can feel it.

Ni5mo180SX

I dont know about the popcorn popping one. Ive heard that a lot with mine and it was just had to do with leaky exhaust piping. Metal pinging is the best description IMO.

adamlewis

While it is the most common description, In all the cars that Ive seen knock in ( Rotary AND Piston ) the "popcorn popping" sound fits 100x better with what I heard.

Couldnt really "feel" it though. I wasnt on the gas long enough to get any feel I guess.

Josepi

Detonation=Light popping or Hard metal to metal clanking.

Afterburn=The noise you hear. Basically, your getting unburned fuel to the exhuast and you get those pops. From time to time when my leading ignitor was shot on my 83 i'd get a whole rotor face full of unburned fuel dumped into my exhaust when I shut my car off. After about 30 seconds of being out of the car, it'd go off like a shotgun. I'd get pops between shifts and on decel. My guess is, either your getting to much fuel or lighting it at the wrong times.