Sealing a cast alum valve cover...
 

Well, I have a set of aftermarket valve covers on my AMX, and they are big, cast alum jobbies. Well, when I put them on the first time with just a plain Fel-Pro rubber gasket, I had a leak on the driver's side. I took the cover off, cleaned up the gasket, skimmed it with some Permatex "Right Stuff," and re installed it. It seemed to hold up fine, until sometime in Dec, when I went to start the car up and run it a bit while it is in winter storage. The driver's side started leaking again, so I said "F" it and put the car away. Welp, it was nice today, so I figured I'd go run the car, and see about the leak. Some of the bolts were loose [I'm using stainless Allen bolts], so I tightened them up, and the leak seemed to be taken care of. I drove the car around a bit, and when I came to a stop at a light I noticed smoke coming out from under the car. I got back to my storage garage, and the valve cover was REALLY leaking badly. I tried tightening up the bolts again, but no dice. So I put the car away. Now I'm looking for a fix...and since I already tried my usually "proven" method of gasket and Right Stuff and it didn't hold, I'm looking for ideas...

Have you checked the covers to make sure the sealing edge is completely flat?

- Justin

I had a similar issue way back when after I "gutted" my stock LT1 Aluminum valve covers to clear after market rockers. I ended up using the same method you did with the Permatex and it turned out to be the valve covers flexed when I cut the supports out and I needed to massage the cover lining inwards (if that makes any sense, it was the channel where the gasket goes in and over a center bolt style cylinder head)

I ended up using a small hammer and a good piece of wood.

THAT is something I will have to check!

U could hit these covers with a 10 lb sludge hammer and they ain't gonna budge! These are 'ol skool foundry cast whammer jammers!

Moroso makes a silicone gasket witha steel core that will pretty much seal anything. I am not sure if they are available for AMC but it is worth a try.

I had problems with the rubber gaskets on my alum covers, switched to cork and a little permatex and they work fine.

i used fel-pro cork gaskets on my 87 mustang with cast aluminum covers...worked fine

i have thin aluminum valve covers. cheap moroso. i had the same problem. i went to a thick cork gasket and glued it to the valve cover. installed the valve cover to the head dry. no leaks. i never did trust the rubber gaskets. either no gasket or cork for anything i assemble and usually dont have problems. just another thought on the matter.

A buncha my AMC buddies are raving about SCI gaskets, so I ordered up a set. I'm also gonna take the cover off and see if the flange is wavy. If so, I'll run it by the local machine shop for a buzz back to straightness.

torch+hammer=good valve cover but, torch+hammer=epic failure too

Anyone ever used Fel Pro Perma Seals?

You mean these?

http://store.summitracing.com/partde...0&autoview=sku

I used the cork ones and they worked good, until one of the welds in the valve cover cracked and leaked oil. Damn sheet metal POS lol

I just got a set of SCI cork gaskets in the mail...now I just need a nice warm day to try them out!

thats them