Cometic Head Gasket Oil Leak??

[ck67goat]

I finished installing new High Port heads on my 428 the month prior. I used Cometic .027 thick gaskets, installed dry. My static compression ratio is around 11.8 and and cylinder pressure around 170-175. I'm running an ARP stud kit and heads torqued down to 100. I finally had a chance to get to the track yesterday and managed 2 runs. After the 2nd, I popped the hood and noticed some oil on the top of my filter, so I checked to make sure filter was tight and rechecked housing torque - both seemed fine. Took car home so I would not leave the unknown leak source to chance. Parked the car in the garage and this morning found a couple small puddles of oil on the floor on both sides of engine. Valve covers are dry all around as are top of heads. Jacked car up and finding the block is pretty wet on both sides as is most the bottom of the car with oil. Running my finger on the head gasket tab that protrudes between head and block and I get clean oil. Is the .027 too thin for a street/strip application? Pretty sure I cleaned the block face fairly well before laying the gaskets and new heads on. I installed the gasket dry as my engine builder recommended. Right now seems only have an oil leak and oil seems clean with no antifreeze problems. Spark plugs all check clean so very odd I'd only be pushing oil out on both sides - I've never seen this happen before and have had no oil leakage issues from this engine prior to this head swap. Do I simply re-check the torque or should I start completely from scratch and pull the heads off to check these gaskets? Anyone else ever experience a similar issue with these head gaskets?

[tom s]

I have read that Cometics need a certain finish on the block and heads.Did yours have what they require?Tom

[ck67goat]

I have read that Cometics need a certain finish on the block and heads.Did yours have what they require?Tom
My block was originally decked way back in '96, so unsure about that finish. The heads were sent by Kauffman to my machine shop who also sold me the gaskets, so pretty sure the shop knew the finish needed on the heads.
I did just get a PM from another member who says he's seen a groove in some Cometic Gaskets that cause the leak. Wish I took a picture of the gaskets before I installed. Here are the pics of the block and heads before I installed - block pic is before I thoroughly cleaned off the old gasket (Fel Pro).

[slowbird]

Valley pan leaking or distributor leaking? Just somethings to double check.
Seems odd the head gaskets would leak oil but not antifreeze or compression.

[Mike Kasparian,Sr.]

I have noticed when I install cometics dry and then during teardown after season I see alot of oil between gasket layers . I have been using copper permatex spray between layers , seems to help .

[ck67goat]

Valley pan leaking or distributor leaking? Just somethings to double check.
Seems odd the head gaskets would leak oil but not antifreeze or compression.

Valley pan, distributor and top clean as a whistle. Agree this is odd.

[ck67goat]

I have noticed when I install cometics dry and then during teardown after season I see alot of oil between gasket layers . I have been using copper permatex spray between layers , seems to help .

Interesting. What thickness gasket were you running? .027 is the thinnest I've ever run. The Cometic have the crush around the bore which likely seals the chamber well. Seems odd only oil leaks and not coolant.

[Mike Kasparian,Sr.]

I have used .040 to .060 , from 3 to 5 layer gaskets . Dry deck no water holes in gaskets . You ever pull the head studs and notice all the oil on threads that go into block ?

[ck67goat]

I'm thinking I have a defective set of gaskets. Anyone have any other ideas before I pull the top of engine off again?

[charlie66]

The ARP studs are suppose to be torqued to 110lbs. If you never retorqued the heads you should as well when cold .. Call ARP...

https://static.summitracing.com/global/images/instructions/arp-190-4305.pdf

[PAUL K]

I'm thinking I have a defective set of gaskets. Anyone have any other ideas before I pull the top of engine off again?

I would suggest calling Cometic first.

[ck67goat]

Called Cometic and they were unsure. No help on torque spec. either - they said as per manufacturer. I really can't imagine 110 ft. lbs vs. 100 would be an issue unless this is recommended for a thinner gasket? I'm very hesitant to over- torque an aluminum head, especially since the studs are already likely tighter than bolts. For the amount of oil I'm losing, it is an active leak, not just seepage. I'll get a 2nd set set of eyes on this before pulling top off but wanted to post this here in case anyone has had a similar experience.

[GTOGEORGE]

Remember when torqueing head studs it depends on what lubricant you use on the threads!


GTO George

[lakefect]

is that pic of the block the way you put it together? that doesnt look very smooth

[ck67goat]

Update - looks like I found at least one source of a leak. Car was out of my possession early this year to install a coverter, rear end and an oil change. I'm finding lots of things this shop screwed up, such as installing the brake shoes backwards. Now just found 4 oil pan bolts that literally turned by finger. Not sure that is the source of the issue but now I'm worried what else these guys did while they had the car so have to spend time completely going through it.

[ck67goat]

is that pic of the block the way you put it together? that doesnt look very smooth No, that was before cleaning thoroughly. Keeping fingers crossed the loose oil pan bolts are the culprit as noted above. I'll be checking a few more things before I fire it back up to see if the leaks are gone.

[Mike Kasparian,Sr.]

There usually is a small gap at each corner of head by valley pan also . Need to put a small dab of rtv to seal . Just something else to check .

[Jack Gifford]

Umm... Unless it's an ancient Pontiac V8 with rocker oiling through the studs, I'm not aware of any pressurized oil anywhere in the heads.:huh:

So... with the lack of pressurized oil, any oil exiting at the head gaskets could only be by gravity acting on drainback oil. Which wouldn't amount to much unless there were a fair-size leak path.

Continue looking for other sources of the oil.

[Dragncar]

Jack is right. Never heard of a oil leak only on a head gasket. Just does not happen.
Oil leaks are funny sometimes. The source is a long way from where you see it sometimes.
Get a bunch of carb cleaner and make it all spotless and start it up and start looking.

[tom s]

I have NEVER plugged the oil hole in early blocks and have never had a oil issue with any head gaskets BUT have never used the Cometic.Tom

[tom s]

Interesting thread from Speedtalk.
http://speedtalk.com/forum/viewtopic.php?f=1&t=55003

[taff2]

I had the same problem with my solid copper head gaskets, oil drains down onto the gaskets and migrates to the outside. The cure is a couple of coats of copper spray on both sides of the gasket. I wouldn't fit any MLS gasket without coating them with copper spray, there's no downside to using it despite what the gasket manufacturers say.