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

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

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

Terrible problem to have.

Dan      Kingman Az.      86409

the car makes too much HP, That's why!

Frank/Rebop

Bristol, In ( by Elkhart) 

Paul:

Could be, they are about 1/4".

John - "The Hoosier Hurricane"

John: I'm far from a Headers expert.. but maybe your header flanges are to thin a guage?

Paul

Paul:

My Sandersons on the race car are 1 5/8 OD primaries and 3" collectors with no mufflers or tail pipes.  I regularly blow header gaskets.  If headers are supposed to be exhaust extractors, why do I have enough pressure in my headers to blow out the gaskets?  My next set will be 1 3/4 primaries with maybe 3 1/2 collectors, fenderwell type.

John - "The Hoosier Hurricane"

Just curious? Are all the above mentioned headers 1-1/2" diameter? According to J. Mummert, his testing indicates that the Y-Block does not respond well to under 1-5/8"...

Paul

Thanks for the info.

"The Master Cylinder"

Enjoying life at the beach in SOCAL