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MG MGB GT V8 Factory Originals Technical - Rocker/Valve Cover

I have a Rover 3.5 with Rover rocker/valve covers. They have been a source of most, if not all of my oil leak problems. I ordered new rocker cover gaskets but these were the wrong size and had to be cut down. I suspect they were for a Buick. At any rate they still leaked. I finally siliconed part of the gasket which was leaking and this helped quite a bit, but not completely. So trying to solve it once and for all I took the rocker covers off, put a nice bead of silicon on the rocker cover and then on the rocker cover gasket where it would mate up with the top of the head. I left the silicon to partially cure and then installed. Unfortunately they are still leaking. I was wondering if it might be an idea to do away with the rocker cover gasket all together and just use a bead of silicon?

The Buick and Rover should interchange, I use a molded gasket for Buick 215 on my Rover heads and rocker covers. I would make sure that your valve covers are perfectly flat and no knicks on the heads. Is the oil leak confined to one area? I've used only silicone before and works well, just make sure you don't tighten down too much as some silicone might be cut off and float around in your oil passages. If your old cork gaskets are still intact maybe you can pinpoint where they were leaking. Good luck.

What is a molded gasket?

The heads donít have any nicks. Guess I screwed up with the silicon. Oh well, will try again. But thanks for the tip about not tightening too much.



This link may be useful:

and although the site mainly deals with MGA's some of the stuff there is applicable to other cars too.

As an aside, I had a similar problem on a Renault 16 and the cure was to get a straight edge on both the head mating surface and the metal rocker cover.

As it turned out the edge of the cover was seating at an angle and not close to flat and parallel as it should have been due I believe to some "panel work" by the PO.

The eventual solution was a new cover but an interim solution was to find any gaps and gently bent the edge of the cover with a pair of pliers so it seats flat on the head.

Preparation with a wipe of petrol to remove all traces of old gasket material and any sealant.
Coat one side of the gasket with gasket sealant (I use a brand called Stag which is not silicon and dries tacky) and put it on the head.
Coat the other side of the gasket in place on the head and inatall the rocker cover after wiping the mating surface as before.
Tighten enough to seat all the way around but not so tight that the gasket bulges or sealant is forced out.
Allow to dry usually overnight and then run the motor.

Good luck, Pete.
Peter Thomas

Bruce, the molded gasket is a rubber/silicone gasket that I prefer to use rather than cork. The cork gaskets burn up/ harden too quickly and require more frequent changes. The rubber ones can be reused several times before needing replacement. Looking at my engine, I noticed that there is very small clearance between the rocker cover outer lip and the intake manifold (standard rover cover/offenhauser intake). Using a thin gasket or silicone could produce iterference problems depending on your application.

I am interested in this molded gasket. Would you have a part number for it?

Felpro #
VS 12993R1, I'm 99% sure that's the number(can't read my own writing!) The gasket has some extra tabs on it, just cut them off if needed. Good luck.

Joaquin, tx

Thanks for the numbers


Finally got the felpro rocker gaskets. And finally after all this time my oil leaks are fixed. Thanks all.


This thread was discussed between 10/06/2002 and 21/06/2002

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