Valve cover gaskets

Carmine

Well Known Member
Supporting Member 10
Hi everyone. The new cork gaskets on my valve covers aren't going to work. Still leaks. The ones I took off before tearing the motor down, were a rubber compound. Could have been a rubber/cork compound. Not sure. But, they didn't leak. I can't seem to find just a rubber gasket if in fact they even make one. I see that Mahle makes a cork/rubber gasket part #VS38408. This is as close as I can come. What is everyone using for their valve covers?? Has anyone tried the above gasket?? I have to stop these leaks before I move the car, so I have to address it real soon. Thank you, Carmine.
 

La Hot Rods

Well Seasoned Member
Supporting Member 15
Are you having a problem with the new rocker arm adjusters holding the cover up?
 

Carmine

Well Known Member
Supporting Member 10
I don't believe so. I don't feel any contact when I put the valve cover on. It seems to seat properly on the head. I don't hear any noise when the motor runs. I had the cover off today and looked inside. Not looking for anything in particular, but I'd like to think that I would have noticed some shine or indication of contact/wear. I also quickly looked at and felt the rockers. Nothing really piqued my interest. It is a good point though. I'm going to take a valve cover off tomorrow and have a look. Never had this problem before taking the heads off. The only thing that changed were the rockers and valve cover gasket, Carmine.
 

La Hot Rods

Well Seasoned Member
Supporting Member 15
It was just a thought.
I have had good luck with rubber gaskets....I use brush tack or 3m super weatherstrip adhesive to glue the gasket to the valve cover...then when it has cured and stuck well I install the cover to the head dry.
The problem with trying to use a sealer between the head and gasket is that it almost impossible to get all the oils out of the head where the gasket sets and sealer will not stick to the head if it has any oil on or in it.
 

Carmine

Well Known Member
Supporting Member 10
It was just a thought.
I have had good luck with rubber gaskets....I use brush tack or 3m super weatherstrip adhesive to glue the gasket to the valve cover...then when it has cured and stuck well I install the cover to the head dry.
The problem with trying to use a sealer between the head and gasket is that it almost impossible to get all the oils out of the head where the gasket sets and sealer will not stick to the head if it has any oil on or in it.

I do the same, only I use the blue silicone. Once the silicone holding the gasket is cured/dried, I would then install the valve cover. Just wondering, is there anything wrong with putting a thin layer of silicone on the gasket, letting it set up some, and then attach the valve cover?? Kind of a little extra insurance against leaks, Carmine.
 

La Hot Rods

Well Seasoned Member
Supporting Member 15
The problem with trying the sealer between gasket and head is that the cast iron is so porous and real hard to get all the oil out of it so the sealer will stick.
GM used only the orange color sealer like silicone on valve covers in the 80s and it held real good for about 3 years. For the mechanic in the dealer the fix was to clean it up and use the sealer again but it wouldn't stick because of the oil in the porous of the cast iron.
The sealer was called GMS
 

wristpin

Well Known Member
I hate oil leaks whether on a bike or car so I use brake cleaner on a rag to clean surfaces AND while running a tap I'll squirt some brake cleaner into the bolt holes. Then I'll use PERMATEX BLACK ULTRA GASKET on the metal seating surfaces letting them cure while spreading some onto the gasket surfaces. Do not use a lot anywhere or you're getting it into your engine later. Put the coated casket into the valve cover then put both onto head. Using Blue Loctite put valve cover bolts into place and torque to spec. Let cure for hour or two. I don't use red or blue permatex because they always seemed to be to high in silicone and not enough in rubberish compound. Just my opinion.
 

La Hot Rods

Well Seasoned Member
Supporting Member 15
If you can get the head clean use some of that right stuff with no gasket...but if you have to remove it....well....its not going to be easy. They should call it bad stuff.
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You can use it with a rubber gasket. I wouldn't use it on the cork you stand a chance of the cork seeping.
 

Carmine

Well Known Member
Supporting Member 10
Why not use your old ones? I use the black rubber type and reuse them over and over again and no leaks. I did do some prep work on the head that helps.

Stupidly threw them away. They didn't leak, but just had to change them. I regret that one, Carmine.
 

Carmine

Well Known Member
Supporting Member 10
I hate oil leaks whether on a bike or car so I use brake cleaner on a rag to clean surfaces AND while running a tap I'll squirt some brake cleaner into the bolt holes. Then I'll use PERMATEX BLACK ULTRA GASKET on the metal seating surfaces letting them cure while spreading some onto the gasket surfaces. Do not use a lot anywhere or you're getting it into your engine later. Put the coated casket into the valve cover then put both onto head. Using Blue Loctite put valve cover bolts into place and torque to spec. Let cure for hour or two. I don't use red or blue permatex because they always seemed to be to high in silicone and not enough in rubberish compound. Just my opinion.
I don't think I've ever seen torque specs on valve cover bolts. I will look again, but do you happen to know what it is?? Thanks, Carmine.
 

Jeffrey Osstyn

Well Known Member
Supporting Member 3
I used the thick cork gasket from Show Cars, had to use longer bolts than the stockers, but no leaks and only used small amount of sealer on the cover side to hold the gasket in place. Also used small spreader bars under the bolt heads to spread out the clamping force.
 

Carmine

Well Known Member
Supporting Member 10
Are you having a problem with the new rocker arm adjusters holding the cover up?

You are 100% correct hot rod.
Out to the garage early this morning and took a close look at the passenger side valve cover. I saw what appeared to be like a very small bubble which I had seen before. I initially thought it might have been a minor crack in the paint. Felt it. No bubble. Actually a dent from the inside. This was in the area of where #2 exhaust rocker would be located. Looked at the far end and saw the same thing where #8 exhaust rocker would be located. Took off the cover and looked closely at the locking nuts. Not a mark on them. Put the cover back on and it seemed to seat well on the head. Removed the cover and lined it up where it would be sitting on the head. The locking nuts on those 2 rockers are right where the dents would be. Wiped the oil from inside the cover and you could see what I describe as something a little bit more then a scratch mark, opposite the dents. It is not at all deep, but it is there. It's probably about 1/4 of the circumference of the locking nut. Circular in size. There is no doubt that these locking nuts held up the valve cover just enough to make it leak. I didn't take the other one off yet, but it also has the same dent/position on the #1 exhaust rocker. Couldn't see further down because of the power brake booster. So, what to do about. Here are some options as I see them. May be more and I am certainly all ears.

1-seeing how I don't need to raise the valve cover up that much at all, I was thinking about gluing together 2 gaskets. I'm not sure how well they would stay together though.
2-buying those aluminum valve cover extenders from ShowCars. They look to be about 1/4"thick so that would be more then enough.
3-taking off the locking nuts on both sides causing this issue, and take them to the machine shop. For sake of argument, have them cut the top nut 1/8" or so. This would be plenty and I still would have metal left to put a wrench on.

I'm not keen on 1&2. Presently, I have barely enough room to attach my choke heat tube to the carb. It practically rest on the valve cover. I want to keep this. If I raise the valve cover, I'm afraid I won't be able to attach this.
I don't see anything wrong with cutting the locking nuts down some. As explained, I don't need a whole lot. I would still be able to get a wrench on them. Besides, these are hydraulics. These don't get adjusted that often. After this episode, I hope to never have the valve covers off a again. So this is the option I am leaning towards.

Anyone's thoughts on this would be appreciated. Other options I'm not seeing?? I'm also going to supply some pics. Thank you, Carmine.

valve covers 1.JPG valve covers 2.JPG valve covers 3.JPG valve covers 4.JPG
 

Carmine

Well Known Member
Supporting Member 10
I used the thick cork gasket from Show Cars, had to use longer bolts than the stockers, but no leaks and only used small amount of sealer on the cover side to hold the gasket in place. Also used small spreader bars under the bolt heads to spread out the clamping force.
Interesting. I know on my 348/434 stock valve covers, I used the thickest valve cover gaskets I ever saw. I don't know where I got them from and have purchased many sets since then, but none ever this thick. This could very well be an option for me. Thanks, Carmine.
 

Jeffrey Osstyn

Well Known Member
Supporting Member 3
I have the late style rocker arm adjusters with the center set screw, roller rockers and screw in studs, which sit taller than the stock ball style rocker arms and nuts. No clearance issues with the thick gasket.
 

wristpin

Well Known Member
Maybe the question is " why do #1, #2 & #8 exhaust valve rocker nuts hit your valve cover?" They shouldn't. Can you post pictures of those and a few others please?
 

Bungy

Well Known Member
Supporting Member 3
I'm pretty sure Show Cars sells the "thick" valve cover gaskets.
 
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