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Silicone Valve Cover Gasket Installation

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Michael Oritt

Michael Oritt

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I recently bought a "Gasket Innovations" silicone valve cover gasket, the section of which is roughly D-shaped.
The website instructions say that for an aluminum valve cover with a flat flange (which is what I have) either side of the gasket may be glued to the cover.

My instincts tell me to attach the flat side of the gasket to the cover flange so as to allow a bit more surface area for bonding, but I would appreciate knowing others' experiences as well as adhesives used.
 
I installed one on my TR-6 last year. I put the flat side toward the valve cover. Don't use too much sealant. Just a continuous bead all the way round. After I put the silicone on, I placed the valve cover, face down on a flat surface with a few pieces of masking tape holding it here and there until the silicone set up a bit. I torqued the cover down lightly with a torque wrench according to specs. It has not leaked yet. Have fun...J.D.
 
My go-to to for affixing gaskets to valve covers, at least cork ones, is 3M Upholstery Glue (aka 'yellow snot,' though it comes in black). Should work on silicone too, and 3M Adhesive Remover to clean it off (works so well they banned it in California).
 
Trouble with that stuff is that it becomes hard as a rock. I worked in Volkswagen garages back in my youth. 3-M yellow snot was common practice on the VW valve covers. We used to clean it off on the wire wheel. When I bought the TR in 2023, first order of business was to get rid of all the leaks. It has been quite the "crusade" but she is dry now. Hope it stays that way. ...J.D.
 
Thank you all for your input. I agree with WW that the yellow peril can sometimes harden to the point that a cork gasket gets destroyed in the process of removal. I was thinking about using the blue Hylomar or equivalent which remains relatively flexible.

My valve cover is one of the early AL finned models and I am waiting for a replacement badge which is riveted to the top of the cover so I will probably not get around to the installation for about two weeks, but I will definitely post the results
when the install is finished.
 
I don’t have the aluminum valve cover but I did use the silicone gaskets on the valve and side covers . High temp silicone used sparingly to hold the gasket in place with additional masking tape in a few places . Tighten I’d down gently and only tighten it a bit more if it leaks .
 
I also have a 1/4" drive torque wrench that measures in inch pounds for jobs like this. ...J.D.
 
Michael Oritt said:
I recently bought a "Gasket Innovations" silicone valve cover gasket, the section of which is roughly D-shaped.
The website instructions say that for an aluminum valve cover with a flat flange (which is what I have) either side of the gasket may be glued to the cover.

My instincts tell me to attach the flat side of the gasket to the cover flange so as to allow a bit more surface area for bonding, but I would appreciate knowing others' experiences as well as adhesives used.
Click to expand...
Glue flat side to valve cover flange - more surface area, holds gasket in place.
Rounded side faces engine head - compresses evenly to seal.
Adhesives: black silicone RTV like Permatex Ultra Black or 3M Black RTV. Use a thin bead to hold the gasket, not the whole surface.

Clean surfaces, let adhesive tack for 5–10 min, torque bolts gradually, allow full cure before heavy engine use.
Corners and midpoints are usually enough—no need for a continuous bead.
 
Hi Thojr--

Thanks for the input. I'm still using the old cork gasket, holding off on using the silicone one until the oval plate comes back from being re-enameled, but I'll certainly report back once I do the final install.
 
I recently found my silicone gasket leaking between the original steel rocker cover and 6-cylinder head. I took the rocker cover off and using a flat surface (outdoor glass table top), I found that the rocker cover had a bit of a twist to it. I held the front down and using a 3/8 socket extension in the T-fitting, I twisted it back to square. That stopped the leakage. Just an observation if you still have leakage with the silicone gasket.
 
Back in February I posted the initial question asking for advice on installing a D-shaped silicone gasket to an early finned alloy valve cover. The great majority of folks on this and other sites recommended attaching the gasket flat side to the cover. Permatex Ultra-Black seemed to be the sealant of choice.

At the time the early chromed brass & ceramic plaque was being restored by Karla Maxwell, which I finally got back about two weeks ago. At Karla's suggestion I refastened the plaque using threaded rivets to match the period appearance and yesterday I glued on the new silicone gasket flat side to the cover using Ultra-Black. This morning I cleaned off any sealant that had oozed out from under the gasket, gave the cover a final polish, and reinstalled it on the engine. After two heat cycles there are no oil leaks. See attached pic.
 
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