tjbreen

Pulled the exhaust manifold today to see where my crack was in the #1 tube that was coating the back of my distrubutor with black exhaust. When I removed the copper gaskets that seal the manifold to the crossover, I discovered that one had three cracks in it, one clean through and the hole in the middle was no oval shaped. This did not happen during removal, there is soot in the cracks and two of the bolt holes are oval too.

These have less than 1,000 miles on them and I followed the instructions and left the old O-rings in the grooves. Not sure what to do to seal this joint now. Should I go back to just sealing rings?

tjbreen

Heard from a racer today that retorquing is the key to keeping copper alive. I have these in other cooler places and have not had a problem. I also took a file to the header flange and it was not flat. The areas near the bolt holes were higher, which may have allowed this gasket to walk.

60Driver

Has anyone experienced corrosion between the copper gaskets and the exhaust flange?

The galvanic difference between steel and copper is pretty high and may help explain early failure of the part.

Mark-87-951

Interesting. I just installed copper gaskets at the crossover and should be doing the same at the exhaust to header connection. I'll have to keep an eye on them and see how they hold up.

CPR

I would think not really an issue as the heat dissipates any moisture that would become the 'potential' electrode in a galvanic corrosive situation....unless of course the car sits idle for long lengths allowing condensation or rainwater to settle.

I switched them out 3 years ago when upgrading the exhaust, then again recently when installing a new turbo....the old ones looked fine (17k miles and 3 ears on them).

tjbreen

My problem was not decay but cracking due to deformation. I do have a new set of copper manifold to head gaskets that are much thicker and will try those on the head. Sealing duties for the manifold to crossover will be left to the $56 worth of crush rings I purchased today so I could get started bolting the headers back on but the welder never called and has my headers captive in his shop until Monday.

Anyone in the Boston area have a spare 2-3 turbo header?

60Driver

That's a good point. I didn't think evaporation.