73 T/C Exhaust

[1973JPS]

Hi Guys...so 2199 has been up and running now for 1000 miles and I have to say I'm very happy with everything except my exhaust. It's the std cast manifold but I can't seem to get a good seal with the down pipe.....I've fitted new studs, nuts and spring washers along with a double exhaust gasket which I made up from a sheet but still it keeps blowing out after 5 to 10 miles....Any advice apart from the obvious replacement with a 4 branch...Thanks as always

[FranV8]

I had this and then found the actual workshop manual advice is clean the surfaces, and just use exhaust assembly paste between the flanges.

Worked for me for the 5 miles I have probably driven the car so far.  Exhaust gasket blew out immediately....

[EuropaTC]

When I had the cast iron manifold I also had the same problem. I think mine was made worse because the downpipe was stainless and the flange was just too thin (6mm ?) that I could never get a seal. No matter what I tried, gaskets, exhaust cement, nothing worked for long.

In the end I removed the downpipe and brazed a "socket" inside both halves which protruded into the cast iron manifold, making a spigot & socket joint on both exits. That worked perfectly although no doubt impeded the exhaust gas to some small extent.

Brian