How did you fix your valve cover leak?

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cruiser

cruiser

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Guys/gals: The valve cover gasket on my 1974 225 slant six leaks. The valve cover itself is not bent or deformed. How did you eliminate your valve cover leak? Cork gasket or something else? Did you use RTV on the cork gasket before you installed it? Tired of cleaning oil off my garage floor. Please let me know how I can permanently eliminate this problem. Thanks!
 
Being a 74 you sure it isn't the spark plug tube o-rings that are leaking?
 
I made sure the bolt holes were flat and used a cork gasket. I tried one of those fancy silicone gaskets and it leaked like a busted dam.
 
making sure the rails are flat and the holes haven't been pulled in is critical. You might try some of the aftermarket pieces that go under the bolt head to spread the pressure. I actually like the silicone gaskets with the metal core...
 
Cruiser,
Put a 6" nail in the garage wall. Write 'antique' above it. Hang all cork gaskets on the nail.

Edelbrock make a thick rubber gasket which is a 'sandwich': two pieces of rubber with a steel insert in the middle. Not sure if they have for the slant.

If not, one thing you can do is 'make' a silicon, which I have done a few times.
Remove old gasket & clean surface back to bare metal. Fill the gasket trough with silicon, up the level of the lip on the v/cover; leave for a week to fully cure. There is your new, forever, gasket.
 
I don't fill my oil all the way so there is not enough to leak out....
 
cruiser said:
Guys/gals: The valve cover gasket on my 1974 225 slant six leaks. The valve cover itself is not bent or deformed. How did you eliminate your valve cover leak? Cork gasket or something else? Did you use RTV on the cork gasket before you installed it? Tired of cleaning oil off my garage floor. Please let me know how I can permanently eliminate this problem. Thanks!
Click to expand...

Main thing is to make sure your gasket surface is clean and flat on both the valve cover and head surface. I use a body dolly to flatten any distortion from the bolts. Thin film of RTV on the valve cover, Clean the head sealing surface with lacquer thinner, and install. If there are any casting flaws a very small dab of RTV should seal it. Don't over tighten the bolts. You are better tightening them 2 or 3 times after running for a while, than over tightening them once.
 
Bewy said:
Cruiser,
Put a 6" nail in the garage wall. Write 'antique' above it. Hang all cork gaskets on the nail.

Edelbrock make a thick rubber gasket which is a 'sandwich': two pieces of rubber with a steel insert in the middle. Not sure if they have for the slant.

If not, one thing you can do is 'make' a silicon, which I have done a few times.
Remove old gasket & clean surface back to bare metal. Fill the gasket trough with silicon, up the level of the lip on the v/cover; leave for a week to fully cure. There is your new, forever, gasket.
Click to expand...
Nobody makes one for a slant 6. Cork is the best option.
 
I use the 3M Black Weatherstrip Adhesive on the valve cover side. I use the wide spring clips all the way around the valve cover to press the gasket on the adhesive. Then after that dries I put a thin coat of silicone on the other side and install the valve cover. I haven't had one leak yet,
 
I'm about to try one of those "real" gaskets on mine
cork always did ok at first but didn't last long
 
Glue the gasket to the valve cover.Cork is best but requires regular use to keep it wet..like a wine bottle cork it needs to be wet to keep from drying out, that's why wine bottles with corks are stored on their side.
I've never had any luck with the silicone rubber.
 
RustyRatRod said:
Scruff read this and told me to tell you "Talk to the paw"
Click to expand...



RRR 4.jpg
 
10W90 thick enough to never leak out. Just give it an extra 10 minutes to warm even in the hot summer. Learned that on RoadKill:poke::poke:
 
take off cover hammer the flange flat
put back on with new cork... glue it to the cover if you wish with a light smear of sealer
do the little bolts up with a 2 inch long spanner hand tight so that the gasket compresses just a bit
drive it to get it hot
go round the bolts when hot one more time to nip them up if they show any loseness...

job done when they can't be undone with your hand but could be pushed further.... don't do it....with the spanner

they leak becasue they have been done up too tight in the past and the cover flange is no longer flat.
gasket should be compressed no more than about half of its thickness
if you pin each bolt hole down, metal to metal you split the gasket and the areas in between bow up and it leaks as the head and tin expand and contracts
if it just FLOATS on the gasket expansion and contraction is catered for in the soft cork.
the rubber ones just squish out like a slimy mess... twice the price twice the grief...waste of time and effort.

fitting cork gasket is like fitting rope seal anyone can do it but success involves doing it right.

doing it right involves a slight concern that the bolts are not done up tight enough.... if this concern plays in your mind in the days following... you did it right
 
One good solution taught to me by an old mechanic was to check the obvious, of course, make sure the valve cover flange and holes are nice and true. Clean and tap/clean the bolt holes in the cylinder head. Make sure all sealing surfaces are clean of grease and oil and free of old sealing materials. Then when you are ready for the install, using engine paint in a can, spray both sides of the cork gasket with a film of paint. The paint seals to all the mating surfaces and helps prevent leaks. This has worked for me.
Just make sure to paint the cork side that mates to the valve cover first and affix it to the VC. Then paint the side that mates to the cylinder head. Not alot of paint, just enough for a film thats sticky as you are putting it together.
 
cruiser said:
Guys/gals: The valve cover gasket on my 1974 225 slant six leaks. The valve cover itself is not bent or deformed. How did you eliminate your valve cover leak? Cork gasket or something else? Did you use RTV on the cork gasket before you installed it? Tired of cleaning oil off my garage floor. Please let me know how I can permanently eliminate this problem. Thanks!
Click to expand...
I RTV a cork gasket to the valve cover and then only lightly snug it make it flat... once it's dry I give it one last little snug and then fire it up n drive it.
 
MOPAROFFICIAL said:
I RTV a cork gasket to the valve cover and then only lightly snug it make it flat... once it's dry I give it one last little snug and then fire it up n drive it.
Click to expand...
I do similar. I don't use RTV, but I do make sure the valve cover rail is FLAT and then apply some 3M yellow weatherstrip and stick the valve cover on and let it set up. Works every time. Your way sounds good too.
 
Jeff Seighman said:
I got Indy/IMM LA-X heads with a machined flat valve cover rail and Moroso gaskets!
Click to expand...
Well see, the slant 6 has machined valve cover rails. That's why I figured that fancy "REAL" valve cover gasket would work well. Leakinest sumbitch I ever saw. I even sprung for the high dollar fiber reinforced one too and followed the torquing instructions to a tee. Cork seals good, though.
 
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