TR2/3/3A Installing silicone valve cover gasket

[karls59tr]

I'm getting some leakage from the cock valve cover gasket. I had used blue hylomar to bond the gasket to the valve cover then put a thin coat of oil on the side that mounts to the block. Normally this always works but I think i tightened the cover bolts a bit too much this time and am getting some leaks. I do have a silicone gasket that I have had for years but never got around to installing because it looked like it would be hard to get it to retain it's shape since it is not as stiff as a cork gasket. I'm going to give it a try Anyone tried using the silicone gasket and did you put the red RTV on the valve cover side and let it set up first before putting it on the block? How would you hold the silicone gasket there without it moving around?

 

[tr6nitjulius]

As TR6 speaking for silicone gasket alone after decades of using cork gaskets been using the same silicone gasket for 15+ yrs no leaks easy R&R

 

[RichB4493]

I installed a silicone gasket with red permatex and it’s fantastic. I did it only on the valve cover and let it sit flat overnight with moderate pressure on a flat surface. Hasn’t leaked in a year. Take the time to make sure the surfaces are mated properly and the flat side is squarely facing down for the head cylinder.

 

[TRacer70]

My experience with Hylomar is mediocre. Did it the same way as Rich with the sealant between gasket and valve cover only (you want to be able to take it off again for servicing).

Cheers
Achim

 

[mastaphixa]

I have used the silicone gasket on 2 engines and have had no leaks. I attach it to the valve cover with sealant. I can then remove the valve cover to reset valve clearances with no problems and reuse the silicone gasket indefinitely.

 

[mctriumph]

In my experience, the silicone gasket is great once you get it set into the valve cover properly.
ANY silicone(even bathtub) will bond it if left to cure over night. A few bits of tape will hold it in
place.
That said, the cork is also nearly permanent if done correctly. Contact adhesive on the cork is quick and
lasts. YOU MUST then put a layer of grease on the mating surface so it will never become part of the head.
A bit of grease on the silicone is good too. The devil is in the details.
Mad dog

 

[JHaydon]

The company I work for sells the silicone gaskets, and I just had a discussion with them a couple of weeks ago about proper installation.

As others have mentioned, a thin smear of silicone (of just about any type) between the gasket and the cover, and let it set up at least overnight. 24 hours is even better. I like Rich & MD's ideas to keep it flat and in place.

When you install the cover on the engine, you use MUCH less torque than you would with a cork gasket. If your new gasket is indeed a couple of years old this bit of advice might not be in the instructions. Start with just 10 pound-inches (that's less than 1 pound-foot) of torque. If you have the knurled hold-down hardware (1.25" OD), that equates to approximately finger-tight. If you have hex-head hardware, try using a socket with just an extension (no ratchet handle), like a screwdriver.