What is the best Header Gasket??

[chasmat2316]

no need for a gasket, it just gives more room for a leak!

 

[jemook]

Used copper gaskets on my T-Type about 5 years ago. Haven't had any leaks yet.
John

 

[robzombie]

They use no gasket from the factory because the surfaces are machined flat and true.

They don't stay that way however after a few thousand heat cycles and after the seal is broken for the first time unless they are machined again there will be some warping no matter how minimal it might be.

I always have used a quality soft metal gasket that will take up any gaps/warpage, because you will never get the header to seal the same as the factory did without re-machining them.

 

[Nick Micale]

They use no gasket from the factory because the surfaces are machined flat and true................

Another reason the stock headers will seal w/o a gasket is the head flange is thinner than most aftermarket headers, and will comply better to the head.

If the stock headers were removed at a dealership, they many times would have exhaust leaks as they do warp like Rob stated, but a common fix then was to cut the header flange between cylinders so each cylinder could seal.

It did not matter if the flange was warped since each port would seal as it was not subjected to stress of a twisted flange.

I have cut many stock flanges that solved this issue, and it also relieves stress on the no. 5 exhaust tube to help keeping it from cracking!

 

[robzombie]

Another reason the stock headers will seal w/o a gasket is the head flange is thinner than most aftermarket headers, and will comply better to the head.

If the stock headers were removed at a dealership, they many times would have exhaust leaks as they do warp like Rob stated, but a common fix then was to cut the header flange between cylinders so each cylinder could seal.

It did not matter if the flange was warped since each port would seal as it was not subjected to stress of a twisted flange.

I have cut many stock flanges that solved this issue, and it also relieves stress on the no. 5 exhaust tube to help keeping it from cracking!

What about aftermarket headers that have thicker flanges? Have you cut the flanges with the same results as factory headers??

I've always had to use [good] gaskets because unless they are straight and true they have a leak no matter how minimal it is.

 

[Nick Micale]

The thicker flanges are in for a trip to our large belt sander as they must be flat for them and the gasket to seal properly!