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MG MG Y Type - Valve/Rocker Cover oil leakage.

An old chestnut, but I can't see an answer in the archives: I've tried several new cork rocker cover gaskets, all of which leak enough to be annoying. I know there's the nitrile (?) version somewhere, and I will definitely try one when I can get hold of one; in the meantime, what's the conventional wisdom regarding using a good gasket goo such as Permatex, not instead of the cork gasket but as well - one side, both sides of the cork? It seems to me anything must be better than just the cork gasket.
Thanks all.
John
J P Hall

John--you need to sit your cover on something flat (sheet of glass) and check it's flatness---If it's not flat you need to rework it till it is
I usually glue the gasket to the cover with contact cement so it stays in place and then grease the cork so it doesn't stick to the head, makes it reusable several times over.
willy
William Revit

Hi John,

Well, I recommend using a good quality RTV sealant between the valve cover and gasket. Install and let the sealant go off completely. Remove, and then replace with a smear of grease between the gasket and the head. This provides an effective seal and allows removal of the rocker cover if needed. I haven't tried a neoprene gasket.

Regards, Ewan
E.J. Ward

Good advice, thank you Willy & Ewan. I'll test a few that I have, pick the best, and seal the gasket to the cover as suggested. The finish line is looming!
John.
J P Hall

If the cover has been overtightened in the past it is probably out of true/shape as suggested by William. People make the mistake of overtightening allthe time with consequences!!
Paul Barrow

Agree, Paul - that's what I was trying to avoid; I realised I was starting to fall for the same thing, so aborted and sought advice. Oddly, one professional over here recommended contact cement on both sides of the cork gasket - which I couldn't countenance. That's when I figured the BBS would help - as always!
It's all done, so road testing tomorrow will tell a story.
John.
J P Hall

John,

Here's my procedure for ensuring a leak-free valve cover gasket. I use cork ones, not the neoprene rubber ones.

After cleaning both the head and cover of old sealer and degreasing (acetone), I apply RTV silicone sealer to the applicable machined face on the cylinder head. I do not apply anything to the the rocker cover. Leave it to us Yanks to do things backwards. Perhaps it's due to our being north of the Equator!

I beieve there are two advantages to this technique:
All of the gaskets I have encountered are larger than the valve cover in length and width. it is easier to orient the gasket evenly on the head rather than the cover; and
By ensuring a thorough bond between the head and gasket, a liquid tight dam of sorts is created to retain oil inside the cover.

Always iInstall the gasket with the engine cold and resist the temptation to start it before the RTV has cured, usually in about 24 hours at ambient temps. I find the cured RTV very easy to remove with a gasket scraper or razor blade, acetone will remove any remaining bits.

Rocky
Rodney C "Rocky" von Dullen

I like your thinking, Rocky. If my first variation (above) is less than satisfactory, I'll go for the combination, leaving the gasket glued to the cover, but with RTV sealing the gasket-to-head surfaces. Sort of a combination of all 3 above! What could possibly go wrong ...
John.
J P Hall

John

Make sure all surfaces are dry and absolutely oil free before you use RTV
Paul Barrow

This thread was discussed between 03/03/2023 and 10/03/2023

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