How to seal cork valve cover gasket

No Worries

Seaman
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Nov 6, 2016
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Gotta check the old girl ('84 3.0 merc) for loose rockers tomorrow and I plan to do it while running. I picked up a quicksilver cork gasket. Do i need to put some perfect seal or rtv on the gasket? One side, both sides? Really hoping to find a loose rocker so I can get on with the season. Any tips or pointers are greatly welcomed.
-Anchors Aweigh!
 

Bt Doctur

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Usually I just put a touch of RTV to hold the gasket to the cover
 

alldodge

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Strongly suggest do not put RTV on both sides of the gasket, it will cause the gasket to slide out from under the surfaces. I would suggest some 3M or bellows adhesive on one side, or RTV on one side
 

Scott Danforth

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I use copper ultra rtv between valve cover and gasket
 

No Worries

Seaman
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I do have some bellows adhesive and aircraft sealer. Wil either one of those work? Thin layer or just a few dabs?
 

boatman37

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I try to avoid cork gaskets but if that's what you have then I glue the gasket to the valve cover using some type of RTV sealant and nothing on the engine side of the gasket
 

Bondo

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Ayuh,.... I use the newer silicone rubber gaskets whenever possible,....

Ya never want to fully coat a cork gasket with any sealants,...
The cork actually suck up a bit of oil to swell, 'n seal,...

As noted above, just a few dabs to hold the gasket in-place,....
 

boatman37

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oh, another thing, don't overtighten them. you will squish the cork out and distort your valve covers if they are stamped steel. just snug them up a little
 

gm280

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Lessons learn with this.

would first, thoroughly clean both surfaces with acetone after adjusting the rocker arms, then it is up to you if you want to use a sealer/glue or RTV or anything else. Permtex makes a gasket sealer glues and that would be my thinking.

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HOWEVER, torque them to the factory's specification and STOP!

With cork, you sequence tighten them at progressive increasing levels of torque and once you get to the factory specification, you stop turning them...period! They will feel like you can tighten them a lot more, but don't. They will work perfectly. If you go by the feel torquing cork, you will smash them and guarantee a leak or three.

I have learn that the hard way. And once I torqued them properly, not a leak anywhere. JMHO
 

Silvertip

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And before you install the cover, check the bolt holes in the cover for "dishing" and if they are deformed, flatten them again.
 

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Seaman
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Nov 6, 2016
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Thank you all for the advice. I didn't even bother pulling the valve cover as I think it's a rod knock.
 

boatman37

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ugh. pull each spark plug wire one at a time. if it is a rod knock it will usually go away when you pull the offending plug wire
 
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