Need Advice-Valve Cover Gasket Thickness

[paul67]

One of my little projects over the winter was to get a pair of Corvette script valve covers polished. They turned out very nicely. So today I proceeded to get gaskets (I prefer cork). The local shop offered Fel-Pro in 5/16" and 7/16" thicknesses. I bought the latter. In the trial fit they look too thick. Will they work without leaking?

 

[67HEAVEN]

Paul,


Assuming that they're nice and flat, there should be no problem. I had to use thick ones for clearance on my 502 as I went with the original BBC covers. I used gasket glue between the gaskets and the covers.

 

[JohnZ]

I use the Fel-Pro Cork-Lam 5/16" (or the plain ordinary cork gaskets), and have never had a leaker, even with repeated removal for lashing the valves. Make sure the mating surface on the covers are clean and flat, and glue the gaskets to the covers with good gasket cement or a bead of Permatex Hi-Temp Ultra-Copper RTV (my favorite), and run the bead all the way around each bolt hole. Let them set up overnight, then install them, and don't over-torque the bolts (distorts the covers, causes leaks). After a few hours' running time, re-check the bolt torques after the gaskets absorb some oil and soften slightly.

 

[paul67]

I got them on with no problem. Cleaned all surfaces and used a thin layer of "goop." (My weapon of choice is Permatex Aviation Form-a-Gasket.) Used a bit of Permatex Copper on the bolt threads. Fired up and let run for 15 minutes. No leaks. I tend to torque by "feel" after having worked as a shade-tree mechanic for ... some time. I will re-torque tomorrow. Thanks John for reminding me.

They look very nice. They are not chrome but just highly polished. I don't normally go for the modern bling-bling (right terminology?) accessories but I have my moments. Those covers are from P........n and I botched a paintjob on them. After a little oven cleaner and some lacquer thinner I thought I would start from scratch. The ones I removed are powder-coated. Hummmm. What next.