Terrible problem to have.

Dan      Kingman Az.      86409

Re the problem of header exhaust gasket failures. If you thinks about it, the hot exhaust is being forced out under considerable pressure, while on the intake side the fuel mix is largely drawn in by vacuum, hence the usually bigger intake valves, so, it's no wonder there is more likelyhood of gasket failures on the exhaust side... yes, no?

Paul

Not necessarily. "Vacuum" in an intake is only a pressure less than atmospheric. For a typical street engine, 20inhg is about 10psi pushing the gasket into the intake. I don't know what the exhaust pressure is in the manifold or header tube but I'm sure it's nothing astronimical. The pressure in the larger pipe, before the muffler can be several psi.



John's case is far from typical, though. He needs to push a whole lot more volume out the exhaust valve than a street car and if the tube diameter is too small, it can kick up the pressure.


Lawrenceville, GA

hello,i have sanderson headers to 2" pipes ,instructions said do not use gaskets.use high temp black gasket sealer,never had a leak,   these are 53-56-f100 headers on a 292 bored .040 over with dome top pistons&G heads.

Darrell Gipson Ala.Gulf Coast