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MG MGB GT V8 Factory Originals Technical - Exhaust manifold gaskets.

Hi, I seem to be having a problem with the exhaust manifold gaskets which keep blowing, causing a VW Beetle type noise! not good on a v8. Im using tubular, block hugging manifolds. The gaskets are made by 'Britpart' (aftermarket LandRover parts)and have only lasted 3 or 4 months. Looking closly at the gaskets it appears that the middle layer blows out and the outer silver metal layers remains intact, dispite the manifold bolts being tight. Anyone else had similar problem? What other makes of gaskets are people using? I'm not ordering any more Britpart ones.

m clemas


Hi Temp RVT Silicone can be used. Must be a manufacturing problem as usually right rear and left front will go.

No problems with SS RV8 style.


I don't know if you can get them there in the u.k. or even here anymore, even further more.... for your particular engine, but i once bought a set of heavy duty truck manifold gaskets for a 351 c.i.d. (ford) made from some type of soft grade copper. I had the parts guy look up a set to fit the the time he could've ordered them, maybe you could search for those? Good luck!
p.s.They never leaked. I re-used them 3 times as i remember

I've had a lot of problems with gaskets. There are two problems - the holes in the manifolds don't line up properly with the holes in the heads, and the holes in the manifolds are bigger than those in the heads. The 2nd problem helps to overcome any partial blocking that will occur due to the first problem, but the end result is that some edges of the gaskets only have about 1/8" of overlap, and the pressures can blow them out. The fact that the tubular manifolds gradually distort in use doesn't help either as the flanges become slightly non-parallel with the heads faces. This results in little or no pressure on some edges of the gaskets and is what contributes to the composition blowing out, I believe. I've tried fat singles (one port each) with silver both sides and a composition inner, thin doubles (two ports) ditto, and thin double green and black all composition gaskets. On the doubles the bar between the two ports helps you to hold them in place while you get the bolts in, but the all-composition type blew out in no time. The thinner types do give you a bit more clearance between the manifolds and the inner wings, but have little crushability to take account of any mis-match in parallel-ness between the manifold and the head. The thicker gaskets give a better seal but being singles are a fiddle to fit. I had continual blowing until I welded struts between the manifold flanges, which keeps the stable *and* pushes them into better alignment with the head ports, and then flatted the faces of the flanges so they are parallel with the head faces. After all that I still had a very slight blow on one port, but it didn't damage the gasket and seems to have closed up in use, possibly from carbon. Either that or I'm going deaf - selective or total.
Paul Hunt

These header gaskets seal very well.
Perhaps, with enough interest they could make some for BOPR applications:


69 MGB 342 V8
Pete Mantell

Hi, thanks for the replys, I've now fitted the later Land Rover twin port type gaskets, (pt. no. ERR6733) they look to be made up of three thin layers of tin, with no composite material to blow out! They are working ok at the moment, but time/ miles will tell if they can hold out.

Cheers Mike
m clemas

What is a 342CID V8?
I've not heard of that size.
c l sorenson

Stroker Ford 302 with standard bore.

Wayne Pearson

The gaskets I got from Clive Wheatly are lasting well.

This thread was discussed between 08/03/2005 and 24/03/2005

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