The head gasket on the passenger side of my 454, developed a leak and we have removed it by loosening the Thorley header and sliding the old gasket out. Summit Racing recomended replacement with a copper gasket. When I called Thorley to get torque specs for the header nuts, they said not to use copper gaskets because Thorley headers have a raised bead around the port area of the header and they did not have good experience with copper gaskets. BUT, they said they install their own stainless/graphite gaskets dry, no RTV sealant around the port area of the gasket. What do you all think? Anyone have experience with Thorley headers and gaskets?

quote:

Originally posted by Jim and Tere:
The head gasket on the passenger side of my 454, developed a leak and we have removed it by loosening the Thorley header and sliding the old gasket out.

You mean you have a "Header Exhaust Gasket" leak correct?

I have a set i have not installed yet but i would use the thorley recomended gaskets because the copper probably won't seal correctly.

Yes, Mr. Bill, it is, was a header exhaust gasket leak. When we took the old gasket off, it had cracked in one place and that's where the leak was. Several other cracks had not opened up yet but eventually would have.

Sometimes a manufacturer will recommend his own product as a means of making a little more money, but usually their recommendations are based on experience.

If a Thorley gasket subsequently fails, you have grounds for complaint, though not necessarily satisfaction. OTOH, if you ignore their recommendation they have no obligation to respond favorably to any future complaint. I've never used Thorley products but they have a good reputation.

quote:

Originally posted by Jim and Tere:
Yes, Mr. Bill, it is, was a header exhaust gasket leak. When we took the old gasket off, it had cracked in one place and that's where the leak was. Several other cracks had not opened up yet but eventually would have.

It would be interesting to know whether that was a Thorley gasket and how long ago it was installed.

My 2001 Thorley gaskets do not leak yet. I put them on dry and cold torqued. Then hot-torqued a little later.

We,(Tere and son-in-law Dan, jet pilot, aka chief mechanic) installed the Thorley gasket dry and cold torqued to 30 ft lbs as suggested by Thorley. I held the shop light. The chief test driver, aka go cart queen, took it for a 50 mile spin and all was fine. The Thorley gaskets had their name on one side. The one I took off had no name and were just probably an off brand. The Thorley gaskets were $36 for a set, about twice what others in the Summit catalog go for. I guess you get what you pay for. I'll hot torque them again