Firing out the back of the valve has always been my understanding of
it. Don't much matter if it is an intake valve causing a back fire pop
out the carb or TB or the exhaust valve causing a back fire pop out the
exhaust pipe.....

This is opposed to firing on the face of the valve like it should in a
cylinder.

But then I don't know who originally coined the work so....

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's

Steve wrote:
>
> The very term "back" in "backfire" is a reference to flame propagation
> "backward" in the induction system- in other words in the intake.
>
> But everyone calls popping out the exhaust "backfiring" also, even
> though its not really the correct term.