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Oil Drain Back from GN1 Cylinder Head with Cometic Head Gasket

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TTipe

Snake Skinner
Joined
Jul 25, 2008
Messages
767
Using GN1's, Cometics & Champ valve covers I'm concerned that a lot of oil will remain on top of the heads due to poor drain back to the pan. The drain back holes in the head are small. The Cometic gaskets are winking part of the drain back holes shut and the heads are obviously on an angle so the oil piles up until it reaches a push rod passage. I should have caught this during "dry fit". Are others seeing this and is it really an issue. I'll bet this contributes to oil leakage at the valve covers. I'm reluctant to tear the heads off the engine. Constructive comments are always welcome.
Thanks
 
Running that set up for years, no problem. 80psi during the runs. Phil.
 
Mine were leaking oil, Lucas stop leak and using strait 40 weight oil, no leaks now. Oil was wicking between the layers of head gasket.
 
I noticed the same thing when I was checking out oil leakage at back of both valve covers. I am running Champ aluminum heads. I don't see any simple solution short of parking car with ass end up in the air! I now have engine plumbing & wiring arranged so I can swap out valve cover gaskets quickly and easily.
Conrad
 
I also noticed what you are talking about. Wondered the same thing. But haven't had any issues. Valve cover gaskets sealing just fine and no oil fluffing out the breathers.

Using:
GN1 heads with cometics
No PCV
Open breathers
TA valve covers
Felpro rubber gaskets trimmed and tucked for perfect fit. Dry installation.
Small dab of loctite on valve cover hold down bolts
 
I noticed the same thing when I was checking out oil leakage at back of both valve covers. I am running Champ aluminum heads. I don't see any simple solution short of parking car with ass end up in the air! I now have engine plumbing & wiring arranged so I can swap out valve cover gaskets quickly and easily.
Conrad
The only solution that I see is to pull the heads and modify the head gaskets so they don't wink across the drain back holes.
 
I tried cometics for a season. Leaked like a sieve. Also saw that drain blockage issue. Went back to felpros and no leaks. If I were to try cometics again I would test fit them, mark the excess and remove it. I believe those restrictions in the oil return caused my seepage.
 
I tried putting gray permatex on gaskets around oil drain, worked for awhile but didn't last. Lucas stop leak seems to be working as of now
 
VC gaskets rubber or cork?
My valve cover gaskets are cork. I sealed the gaskets to the cover rail with permatex high temp (orange ) sealer. Venting the crankcase with open valve cover breathers reduces the pressure in the valve cover.
 
Use the Felpro steel core vc gaskets. The don't leak, need no sealer and are reuseable. Mine have been off a dozen times and still seal fine.
 
I'm having a similar issue with my Cometics. Oil stands on top of them at the drain back holes and seems to leak between the layers down the back of the block. My VC gaskets do not leak, cork and TA valve covers. I pulled my intake and had a friend of mine who's a machinist and engine builder take a look. I want to try and figure out a way to modify the head gasket at the drain back area to allow oil to flow easier and not puddle up on top of the head gasket without pulling the heads. I ran a bead of "right stuff" about 2 inches down the back of the head where it meets the intake prior to pulling it. Worked on the drivers side but not the passenger side. Very annoying.
 
I want to try and figure out a way to modify the head gasket at the drain back area to allow oil to flow easier and not puddle up on top of the head gasket without pulling the heads. I ran a bead of "right stuff" about 2 inches down the back of the head where it meets the intake prior to pulling it. Worked on the drivers side but not the passenger side. Very annoying.
Before I finally pulled the heads, I thought of running a drill or burr down the hole with everything shielded to open up the passage, then sealing a brass tube down the hole to block off the Cometic. I have heard of others removing the rivets and sealing between the layers in those areas. Never went that far with it. I have iron heads and just gave up and went back to Felpros. I've been told by some that they only use Cometics on aluminum heads.
 
Use the Felpro steel core vc gaskets. The don't leak, need no sealer and are reuseable. Mine have been off a dozen times and still seal fine.
Thanks for the "heads up" on the valve cover gaskets. I had a question about your Turbonetics 64/65. Does it spool well for a street car and is yours a DBB or J? Jack and I were talking about the same turbo for my combo. Actually Jack thought I should go with a 66/68 but I think it will be slow off the light. I see that you are making 10 sec power but maybe traction is not co-operating. Considering that you have picked up ~ 6 mph trap and the boost has dropped to 20 psi (east coast air is heavy) you are doing great.
 
Thanks for the "heads up" on the valve cover gaskets. I had a question about your Turbonetics 64/65. Does it spool well for a street car and is yours a DBB or J? Jack and I were talking about the same turbo for my combo. Actually Jack thought I should go with a 66/68 but I think it will be slow off the light. I see that you are making 10 sec power but maybe traction is not co-operating. Considering that you have picked up ~ 6 mph trap and the boost has dropped to 20 psi (east coast air is heavy) you are doing great.
I have a 3000 stall converter, your 3200 should be fine. It's a ball bearing. Since getting the new engine sorted out, traction is harder to come by. I need to install my rear coil overs and adjustable shocks and dump the air bags. I have not been able to get near the 1.5 or 6s I got before.
 
I have a 3000 stall converter, your 3200 should be fine. It's a ball bearing. Since getting the new engine sorted out, traction is harder to come by. I need to install my rear coil overs and adjustable shocks and dump the air bags. I have not been able to get near the 1.5 or 6s I got before.

Why, what is happening that you are now not getting traction that you were getting before
 
I've had issues with both GN1 and TA aluminum heads with oil drain back. On my next rebuild on a StageII with TA heads, I will drill through the lower aft corner of each head and run a -10 AN hose down to the pan. Can do the same with Champion heads I think.
I usually drill the rivets and spray copper coat on all layers of Cosmetics. At a minimum I smear sealant around the end layers and around water ports.. Never install completely dry as they suggest.
 
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