Standard exhaust manifold flange thickness

[james christie]

The question is in the title:

Anybody out there got a standard exhaust manifold to hand on which they could measure the thickness of the flange.

I have my 4 branch stainless steel one in bits and have noticed there is a very small exhaust blow that had darkened the underside of the carburettors. I have a suspicion that the flange is a bit thinner (10.28mm) than the original and is not sealing totally.

 

James

[RogerH]

Hi James,

I had something similar on my 4A. The new (late 90's) exhaust manifold was apprx 5/16" whereas the inlet manifold is a good 3/8 and was happy with the old manifold.

The pear shaped bridging washers can't tilt far enough with the thinner manifold flange. Build up with weld on one side.

 

Roger

 

 

PS - as Stuart mentions it is much thicker than the 3/8 I mention.

Edited September 28, 2017 by RogerH

[stuart]

5/8" or 16mm for a TR3a manifold

Stuart.

[Lebro]

Farily common this, you need to either grind down one side of the bridging pieces, or better to build up one side.

I opted for the latter, & did it by drilling & tapping into the "bump", then screwing in a screw with a head thickness to match the required gap.

I think I used an M4 hex head.

 

Bob.

Edited September 28, 2017 by Lebro

[Ian Vincent]

I welded a small off cut of stainless steel plate onto the SS manifold in the appropriate places, but a washer would have worked just as well..

 

Rgds Ian