Technical Valve Cover Gaskets

I bought some used M/T valve covers for my SBC powered daily, cleaned them up spotless and ordered new gaskets. When they came I was pleasantly surprised, they are metal inside and fall into place, no more gluing or pushing the gasket around. News to me, never seen them before, and only 10 bucks shipped. Chinese?

So after a month or two they are leaking. Before I pull it apart and check the heads and covers for flatness (not likely a problem), has anyone had experience with these gaskets? They were blue in the ad but as I recall they are black.

 

the only way that I have ever been completely successful with sealing valve cover gaskets is to use the MR Gasket extra thick gaskets, glue them to the valve cover with Indian Head shellac then coat the other side of the gasket and set it on the head, snug the bolts up just barely, let the Indian Head dry and then tighten up the valve cover bolts.

The rubber metal core gaskets are meant to be used on a machined gasket flange. All 85 down small Chevies have an as cast gasket surface. They need to be glued down, and made of cork so the gaskets can soak up the oil and swell to aid the sealing.

 

Thanks Jason. Yup I have earlier heads with cast surface so that's likely the problem. Makes sense.

 

I bought a new LS-7 big block crate engine in 1989, and it came with silicone/metal core with metal spacers type valve cover gaskets. I've been using them since 1990, and they still don't leak, with tin valve covers. The lip on the head is machined.

The modern chinese version...hmmm...not sure. If you can get thick cork gaskets, and remember to snug the bolts down occasionally, they should work ok.

 

I used those "new fangled" ($35) FelPro blue pan gaskets on my roadster engine and they leaked on the dyno.

 

The blue Fel Pro pan gaskets work well for me. But I try to use OEM sheet metal, rather than the chinese copy.

 

I have used the Milodon one piece pan gaskets several times with good success. Used with both factory sheet metal pan and a cast aluminum finned oil pan. That's my pan gasket of choice now.

 

This is an aluminum Rodeck block and a Dan Olson pan, assembled by a pro (not me).
Standard gasket replaced it and it sealed just fine.

 

I have never had a set of M/T , Holley valve covers that did not leak

 

I've tried the altra thick valve cover gaskets on a small block and they work great...

 

My never fail system on aftermarket covers of any type is cork gaskets, I put 3M weather strip adhesive "gorilla snot" on the valve cover and then stick the gasket to it. That enabled me to remove and reinstall the valve covers without leaks. I have also installed 2 cork gaskets one thick and one thin glued together to clear roller rockers.

 

Maybe you should step up a bit next time...

 

I'm all in bud, maybe in my next life.

 

Maybe this thread is OT ...Flatheads don't have valve covers.

 

The Ford flathead V8 has a intake for the valve cover.

 

Yeah but it doesn't oil well enough to get a leak up there.

 

I haven't used anything but metal core cork FelPro gaskets on valve covers for years. Just the metal shim cast into the cork, not limiting amount of crush at the bolts in any way. Weatherstrip adhesive on the cover, glue the gasket to the cover as mentioned above. Snug it down and run the engine. Then every time, after running the engine snug your bolts again. Usually takes anywhere from 4 to 10 cycles to get the set. When they don't seem loose after a run session you are good for life! Doesn't matter if it's a machined surface or as cast, steel or aluminum valve covers, nothing matters. Cork, steel core, thick cork gaskets glued to the cover. The trick is in checking them each time after you run the engine until they take their set. Done.
SPark