Tech Q&A - Tips from Members

Manifold Gasket
by Richard Bates, San Diego CA

I recently made an interesting repair to a failed exhaust manifold gasket. We were on an extended trip (4,500 miles.) from San Diego to the deep woods of Vancouver Island, BC when the gasket blew out. The primary cause of the failure was the warping of the manifold. We didn't have a replacement gasket so we cut gaskets from regular higher temperature stock. As we knew would be the case, the misalignment of the exhaust manifold with the engine block did not allow gland rings to be fit, but in this particular circumstance we needed something to augment what was obviously an inadequate seal.

The trick we used was to make exhaust manifold gland rings from copper water pipe. We cut with a hacksaw, as carefully as we could, lengths from the pipe that would extend out of the engine block just the thickness of the gasket material. These rings were split and the joint hand filed until they could be tapped firmly into the engine block counter bore. Our reasoning was that when the manifold assembly was tightened into place the gasket would be compressed somewhat and the interference of the misaligned manifold faces with the copper glands would fix them into place and provide exhaust gas barriers for the vulnerable gasket material. There was no failure of the gasket after the rings were installed. Other antique automobile engines I am familiar with do have these exhaust manifold sealing rings and they make an almost foolproof manifold seal in conjunction with a gasket. Ford had a terrible problem with warping of the manifold and had to abandon the gland ring in production. Our experience in the North Woods with this copper ring approach suggests that the seal can be greatly enhanced. It directs the hot exhaust flame away from the gasket seal and is held firmly in place.

Subsequently we have machined the manifold assembly gasket face flat, and have installed copper glands just because it is so easy to do, and as was demonstrated to us, is effective even without the ring penetrating the manifold counter bore.

Richard Bates
1770 W. Lewis St.
San Diego, CA
Palomar A's Chapter
(619) 296-1707


Last Updated: 01/18/2009