My cylinder heads have bumps near the corners where the valve cover fits. You can see them in the photo. These are in addition to the bumps where the tin attaches.
I was concerned that the rim of the valve cover was hitting these bumps, preventing the cover from fully seating. So, I doubled up on the gaskets to space the cover out a bit.
The first gasket was a silicone gasket I got from Wolfsburg West and then I added a cork and rubber gasket that was very old.
I used Permatex Aviation Form-A-Gasket to stick the gaskets to the cover and to each other. I learned later that this stuff doesn't really stick to the silicone.
After driving the car I discovered that my valve cover leaked. I think as I tightened it down I may have squeezed the gaskets out of position.
When I pulled the cover to investigate I saw that the edge of the gasket was chewed up with a big piece of the cork gasket lying under the rockers.
Inside my oil filter I found bits of cork and a piece or two of silicone.
I have 1.4 ratio rockers and with them the tip of the rocker is closer to the edge of the opening in the head. The rockers were hitting the gasket.
Gaskets are wider than the flange on the cover and the sealing surface of the head. This extra width doesn't do anything but get into trouble with the rockers in my case.
Before reinstalling my covers I am going to trim off this extra width.
After doing some research I decided to stick the silicone gaskets to the covers with Permatex Red Heat Resistant RTV. It needs some time to harden. I cut a plywood piece to fit the cover and used it to press the gasket into the cover while the RTV sets up. I also notched the valve cover edge to clear the bumps on the head. You can also see my urethane vise jaws that are held in place with magnets.
If I didn't already have these covers I would probably try the covers with C-Channel gaskets.
I can't use original style covers with the spring bale because for previous covers I drilled a tapped the holes where the bales attach.
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