Valve cover leak question
 

I have a pretty good valve cover leak right at the back corner on the passenger side of my engine. 65 GTO with older 87 cc edelbrock heads, new enough to use the updated head bolts but old enough to have the old-style chamber.

Do Pontiacs generally or these Edelbrock heads specifically have a tendency to pool oil at the back of the passenger side valve cover? The weird thing is it doesn't seem to leak much when the car is running, but when I turn it off I come back the next day to a pretty good drip onto the passenger side header.

Does enough oil stay up in the passenger side under the valve cover after shutoff to cause what I am seeing?

Thanks!

Are you using a cork type gasket or no?
If it only leaks on one side and since each head is the same, then how could it not be a gasket issue?

These heads are well known to not drain oil well back by the ( rear) last two valves.

If a gasket has dried out and shrunk then you will see a leak show up more when the motor is cold.

Pretty sure it's a thick cork gasket. Do you recommend something else? Valve covers are junky stamped chrome, too.

I've had the V-Covers hit in the corners of the e-heads
you might have to trim the V-Covers in that area.

GT

Seems like I remember that the early E-heads had potential issues with the valve cover mating surface being thin???

This and a slight crack in the adapter emptied my pan in about 30 seconds the last build.

I have never liked cork composition gaskets!

There made of particles that hopefully stay bonded together and after enough time or being tightening they don't!

If I am in a position where I have to use a cork gasket I first seal it on both sides with a film of form-A- gasket and I let it dry fully before I install the gasket.

If you have a wavy stamped steel valve cover in use then that's a very likely cause of your leak, dispite using a thick gasket.

Very common leak area among the many. Cork gaskets are my go to gaskets. I have best luck with them. It's the cheap, paper thin covers and the lack of proper number of fasteners that are the root cause. Make sure you have a high quality, newer gasket in place. I tack it to the cover and install clean and dry on the head. Make sure the flimsy gasket rails are as flat s possible. Hammer and dolly as necessary to get them flat. Use Moroso load spreaders if necessary and the leaks will go away. They don't look 100% stock but are better than an oil leak. I currently have 1 load spreader in that right rear lower location. It was the only way I could get that cover 100% dry. Good luck. Making a Pontiac V-8 leak free is quite an accomplishment. The "Harley of the V-8 engines". Lots of places for leaks.

I actually have better luck with cork gaskets. I tried the thick cushiony edelbrock gaskets made of the foamy rubber material and they leaked like sieves.

The key is to have a straight valve cover for one. Rather than use a hammer and dolly, just position each warped area into a bench vise using the perpendicular lip as a stop, and press into it as tight as you can to flatten it out. It won't work on all types of bench vises but it's the best way to truly flatten them out.

I also use load spreaders for some extra insurance. Don't care if they don't look stock - sometimes we gotta do what we gotta do.

do the thicker aluminum valve covers seal better? seems like they would. also, do they quiet down valvetrain noise?

I have some of these. Pretty solid and not too expensive. Looks like black is all that is available.
I bought natural and welded in some 12 AN bungs and a baffle under them for running a V pump.
These do not have holes but I used to add oil to the engine through the pcv hole in the valley cover with a long/thin transmission funnel.

I have the Edelbrock finned. They are the only thing that doesn’t leak

MGarblick does it the same way as me. Except on factory covers I do a light silicone bead down the bottom back half and 1/2 way up the rear.

I have some thick Edelbrock gaskets. I pulled one off a valve cover that I gorilla snotted on and its cork. Kind of stiff too.
Not sure if they are going to leak or not.
I will have some Fel Pro cork as backup.
O have some Cometic gaskets on my fabricated valve covers and they are pretty thin.

Do you guys loctite your valve cover bolts? Seems like there is enough vibration that it is a good idea.

Do neoprene valve cover gaskets no longer exist? Those were the only ones I never had leak.

Many are listed on this thread:

https://forums.maxperformanceinc.com...d.php?t=848913