"Reversion" Good or Bad??

[Layman]

What is the Theory behind this process???

[Rexone]

Originally posted by Layman
What is the Theory behind this process???
Reversion is only bad when it sucks water back into the engine. It is the natural "reverse flow" of exhaust gasses encounterd at low engine speed or idle through the exhaust pipe. Larger cams with more overlap have more reversion as a general statement. Gil actually did a study years ago on reversion in their exhaust systems by building a transparent pipe and photographing the water droplets working their way backwards on the inside of the pipe with the overlap pulses at idle.
That's why riser height and water exit location within the pipe is so critical especially with large cams. They will suck water right back into the engine if designed wrong.
Reversion without the water factor though really is just a normal part of the engine running. Once engine RPM increases sufficiently reversion is generally no longer an issue.
Hope that helps.

[Layman]

I had a fellow racer explain that reversion actually helps ignite the incoming air and fuel creating more horse power and having baffles in the exhaust creating some back pressure increases this Process making extra horse power.I just was not sure if this could be applied to a Wet Exhaust Systems .
I can recall Switching Carburetors and looking in the intake manifold and seeing all of the water droplets there and wondering where it was coming from??I thought I had a crack head at the time.
Thanks

[Sleek26]

Originally posted by Layman
I had a fellow racer explain that reversion actually helps ignite the incoming air and fuel creating more horse power and having baffles in the exhaust creating some back pressure increases this Process making extra horse power.I just was not sure if this could be applied to a Wet Exhaust Systems .
I can recall Switching Carburetors and looking in the intake manifold and seeing all of the water droplets there and wondering where it was coming from??I thought I had a crack head at the time.
Thanks
I've heard that numerous times over the years but, I don't see a lot of top fuel dragsters or funniy cars with mufflers for back pressure so I'm not enclined to buy it.