Oil leak at valve covers

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Dakota Smith

1976 340 Feather Duster
Joined
Feb 17, 2018
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Georgia
I installed a new set of cork valve cover gaskets recently and oil residue is visible all around both valve covers, but it isn’t dripping oil out. Are cork gaskets just crap? Should I have put some type of sealant under the gaskets?
 
A little contact cement on the valve cover side, grease on the head side. Do not over tighten works for me. If they are OEM most head surfaces are rough and uneven.
 
A little contact cement on the valve cover side, grease on the head side. Do not over tighten works for me. If they are OEM most head surfaces are rough and uneven.

I have aftermarket alum. heads, all smooth on the rail surfaces, I`ve tried about every gasket I`ve seen, and still have a little oily residue under the valvecover rail. I`ve cleaned the cast valve covers too, even have hughs non - burnable gaskets installed the way they recommend-----------
doesn`t drip tho.
right now anyway !
Wish the 440 blocks had the corner drain holes like the elephant !
 
I like the fel pro neoprene rubber valve cover gaskets... Just tell them that you have a 64 - 67 273 for the proper listing.... Those years had adjustable rockers so the rubber neoprene ones are reusable.....
 
Cork are like old cedar boats or wine bottles.Once saturated they should expand and seal.
Like wine bottles stored on their side to keep the cork wet and expanded, if you rarely use your car they will dry out and be ineffective.
always seal to the valve cover,the oil will not run up and overt the lip on the head...over tightening is usually the problem.
i have never had cork leak if properly installed.
 
Cork are like old cedar boats or wine bottles.Once saturated they should expand and seal.
Like wine bottles stored on their side to keep the cork wet and expanded, if you rarely use your car they will dry out and be ineffective.
always seal to the valve cover,the oil will not run up and overt the lip on the head...over tightening is usually the problem.
i have never had cork leak if properly installed.
And if you are using the original type steel covers make sure the metal is flat around the bolt holes. A vice jaw or a 2x4 and a few light taps with a hammer helps straighten them out.
 
I used to use the black rubber gaskets with a thin coat of RTV on both sides, and making sure I had RTV between the bolt shafts and oil side of the rails.
Never a leak.
Cork always seems to seep eventually, and the rubber with RTV never will.

Now that I have aftermarket heads with machined flat rails I use the metal core rubber gaskets, but still use the RTV exactly the same way.
 
I used to use the black rubber gaskets with a thin coat of RTV on both sides, and making sure I had RTV between the bolt shafts and oil side of the rails.
Never a leak.
Cork always seems to seep eventually, and the rubber with RTV never will.

Now that I have aftermarket heads with machined flat rails I use the metal core rubber gaskets, but still use the RTV exactly the same way.

I don`t want to glue both sides, running a solid roller, need to remove once in a while to set/check the valves---- I do have a pair of $38 gaskets on it now. I have built heat guards to help keep the heat off of the valve covers and gaskets, #1-2 tubes are very close to the covers w/ raised port heads. It burned the cork, rubber steel reinforced, and every other kind I tried , ones up after a while , hoping these carbon gaskets will hang in there.
 
I don`t want to glue both sides, running a solid roller, need to remove once in a while to set/check the valves---- I do have a pair of $38 gaskets on it now. I have built heat guards to help keep the heat off of the valve covers and gaskets, #1-2 tubes are very close to the covers w/ raised port heads. It burned the cork, rubber steel reinforced, and every other kind I tried , ones up after a while , hoping these carbon gaskets will hang in there.

Sounds reasonable to me.:D
I am running LA style fabricated aluminum covers with the Magnum rubber over steel gaskets on aftermarket heads with a hydraulic roller, so I don't have those kinds of problems any longer.
It's a daily everywhere car so it needs to be low maintenance.

One messed up thing I found when I had the 318 and used the fabbed covers was the valve cover rails are not flat front to back.
They are higher in the center by about 3/16 inch, so I had to get creative about making gaskets for them.:D
 
Sounds reasonable to me.:D
I am running LA style fabricated aluminum covers with the Magnum rubber over steel gaskets on aftermarket heads with a hydraulic roller, so I don't have those kinds of problems any longer.
It's a daily everywhere car so it needs to be low maintenance.

One messed up thing I found when I had the 318 and used the fabbed covers was the valve cover rails are not flat front to back.
They are higher in the center by about 3/16 inch, so I had to get creative about making gaskets for them.:D
Checked all the surfaces=flat , the problem is the header heat being so close to the gasket----------Think I`m repeating myself , oh well , I`m getting Older !!
 
Checked all the surfaces=flat , the problem is the header heat being so close to the gasket----------Think I`m repeating myself , oh well , I`m getting Older !!

I got ya, and was just relaying what happened with my junk.:D
 
I installed a new set of cork valve cover gaskets recently and oil residue is visible all around both valve covers, but it isn’t dripping oil out. Are cork gaskets just crap? Should I have put some type of sealant under the gaskets?
no they r mother nature . seal them be easy point no oil I think god said was enough.
 
Do you have a PVC valve or a breather ?
Moroso 93055 Gaskets on Stock Valve Covers. Currently torqued at 40"lbs. Installed Breather & PCV.
Generic Directions all makes and models from Moroso is 80"lbs for 1/4" thread fasteners. Seems like too much to me. FSM 40"lbs.
Have not run engine with new valve cover gaskets. Previous FelPro Cork gaskets were leaking, probably because of heat from HP manifolds.
Moroso 93055 Instructions.jpg


PXL_20240320_154349906.jpg


PXL_20240315_195557213.jpg


PXL_20240315_195742068.jpg
 
Looks like these aren't to be used with your vc's?(gasket retention groove) As per Moroso instructions?
Our factory 273 Commando covers have that same groove. Let us know how they work out. I'd hate to spend that $$ and leak from the get go.
Thanks for posting Moroso instructions too
Moroso 93055 Gaskets on Stock Valve Covers. Currently torqued at 40"lbs. Installed Breather & PCV.
Generic Directions all makes and models from Moroso is 80"lbs for 1/4" thread fasteners. Seems like too much to me. FSM 40"lbs.
Have not run engine with new valve cover gaskets. Previous FelPro Cork gaskets were leaking, probably because of heat from HP manifolds.
View attachment 1716224447

View attachment 1716224448

View attachment 1716224449

View attachment 1716224450
 
Looks like these aren't to be used with your vc's?(gasket retention groove) As per Moroso instructions?
Our factory 273 Commando covers have that same groove. Let us know how they work out. I'd hate to spend that $$ and leak from the get go.
Thanks for posting Moroso instructions too
*You're welcome!
*Agree, Moroso 93055 Gaskets are Definitely too expensive to destroy with the wrong torque. I hope heat from the HP manifolds won't destroy the gaskets. My wife says silicone baking materials are good up to 500°F. Hope the automotive materials have just as much strength.
*Chrysler Factory BB valve covers have a ridge, not a groove. I suspect the ridge is for stiffening and to increase pressure along the narrow valve cover rails of the heads. I do not believe a ridge decreases sealing surface like a groove.
If you have HP manifolds and buy a cast valve cover where the wall of the valve cover extends over the valve cover rails, the passenger side (right side) will have fitment problems.
Ridge
PXL_20240228_211718033 LS clean.jpg

Holley Sniper. Returned at a cost to me of $25.
Right side did not fit. Picture from 2/22/24. Wall of valve cover contacts top of exhaust manifold so cannot align with rails. Note: B-Body & C-Body HP exhaust manifolds.
PXL_20240222_210833671.jpg
 
I could not get the Moroso to seal either.. even with aluminum heads and cast valve covers.

20220728_081645.jpg


Ended up using these double stack Felpro cork jobbers with a bit of right stuff...

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