Cometic pics that raise questions.

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disco stu

Active Member
Joined
Apr 10, 2002
I hate to make another Cometic sealing thread, but here it is. I removed my heads before firing the engine and this is what I found. A light coat of oil over the gasket (engine had been primed, for quite a long time until oil came to all rockers). The surface finish is right, and surfaces are completely flat. They were torqued to 85 FT/LBS (studs). I ran Cometics before on this engine with iron heads and but could not tell you if oil made it through the layers because the valvecover gaskets always leaked oil everywhere anyway. I am thinking of a light spray of copper sealer. In threads past some say yes, some no. I am having a hard time deciding but the oil is definately bothering me. FWIW I did retorque multiple times until it stopped taking additional torque

Have a look.
 

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disco stu said:
I hate to make another Cometic sealing thread, but here it is. I removed my heads before firing the engine and this is what I found. A light coat of oil over the gasket. The surface finish is right, and surfaces are completely flat. They were torqued to 85 FT/LBS (studs). I ran Cometics before on this engine with iron heads and but could not tell you if oil made it through the layers because the valvecover gaskets always leaked oil everywhere anyway. I am thinking of a light spray of copper sealer. In threads past some say yes, some no. I am having a hard time deciding but the oil is definately bothering me.

Have a look.
Click to expand...

Attachments Pending Approval.....

No pics..
 
I can't see the pics but I think I know what you are describing. Oil and/or water being forced between the layers of the cometics. For this reason alone we are swapping to the new ICS gasket being made by SCE. Weber racing will stock them for the V6 buick but we have been waiting for over a month for a set.
 
my guess is the moderators are trying to protect the vendor from being bashed, whats up with that, lets see the pictures...
 
That's the newest complaint on the cometics, them leaking between the layers. You can copper coat each side but you still can't seal them off in between the layers. It makes me wonder if all these people having trouble early on with water seaping wasn't caused by water getting between the layers and running out. Any imperfection in the head or block surface will not clamp the gasket properly and allow oil or water or compression to work itself between the layers.
 
Dusty Bradford said:
........but you still can't seal them off in between the layers. .
Click to expand...

I have removed the 2 brass rivets that are under the intake so they would not pop off. So if I coat them I will spray the inner layer too. I am just afraid of compromising the effectiveness of this design by adding a layer (albeit light) of copper sealer that could allow cylinder pressure to eventually blow it out.
 
Disco, what you have done sounds like it will work. I wasn't sure if you could remove the rivets on the cometics. It should seal, the only thing I can suggest is try it and give us a report ;)

Have you looked at SCE's website at their new ICS gasket. It has a V groove with a metal ring in it to seal off combustion gases under pressure. Duttweiler had excellent results from his tests.
 
Cometics

Dusty Bradford said:
Disco, what you have done sounds like it will work. I wasn't sure if you could remove the rivets on the cometics. It should seal, the only thing I can suggest is try it and give us a report ;)

Have you looked at SCE's website at their new ICS gasket. It has a V groove with a metal ring in it to seal off combustion gases under pressure. Duttweiler had excellent results from his tests.
Click to expand...


I have been told that when you spray the copper on that something in the propelent will cause the coating to decay. That may have caused what you can see, and may have allowed the oil to get in there. I assume you have checked to make sure there is no interference holding the head off the deck by even a half thousants correct???
I have also had them leak water prior to start up but not oil. I also have experience with the rivet coming out and after removing them had the small piece (end of the hole) break off and drop into the lifter valley.. So I recomend removing the rivets and cutting the rest of the hole off as well. I think the best solution maybe to seperate them and roll on a silicone something like RJC does with the steel shim.

Dusty as for the SCE's they look great but at this time they are some problems with water passages etc and WILL NOT work with a stock head for sure. Walt Judy and Mike at TA have had a lot of conversation with them and hopefully will be resolved soon.. They look to be a great option in the near future.

Hope any of this helps someone.. I do have cometics on the motor right now but not sure if I will stick with them or not.
 
My opinion is that the copper spray is crap, it is too slimy and messy to use on head gaskets and doesnt seem to adhere very well to any surface. I install Cometics the first time dry, if they are removed to make a repair etc, I reinstall them after applying a light coat of spray Hylomar.I have used the same Cometic gasket 4 times in one case and it is still sealed up tight.I have heard of guys leaking oil on the LT1 engines, I have not had any problems with them. I would suggest to those who use the copper spray to give the Hylomar a shot, it works like a champ.It sprays so lighty, you cant even see it on the gasket until you look at it from almost a level angle.My engine has copper head gaskets and this is the stuff I use to seal them as well.
 
Thanks Bill, Dave, and Dusty.

This is the first I have heard about propellant breaking down the Viton and am quite suprised since viton is gas, oil and coolant impervious. This did not cause the problem though since they were installed dry. FWIW I did a leakdown on the stand and the chambers were well sealed. Just worried about fluids. I have always had leakers and would like to try to keep this thing drier than it has been in the past.

The main reason I posted this was to see how many have had good experience with copper or hylomar. I know Otto posted pics of his blown gasket with an iron head using copper on an MLS. It ventilated the head which caused the gasket to burn and blow out. So it looked like it sealed pretty darn good to me. :eek:
 
I guess I am in second place behind Bill. I have re-used my Cometics twice always spraying them with Hylomar (its a Permatex product that comes in a blue aerosol can...get it at NAPA). These gaskets were even on the motor when it exploded on the dyno two years ago.

I have decided to put a new set on though...time to stop risking it. ;)
 
I ordered the ics titans in dec. and got them in may. They were a 3.850 bore and hung over into the intake side of the combustion chamber. The rtv screen printed seals were also for a stage block and did not cover the water passages for the 109. I talked with caleb at sce a few weeks ago and i think all should be good now. Walt
 
Bumping my old post with an update. I lightly coated the Cometics with Hylomar (between the layers too). I tried not to overdo it because I figured that it would squish and seal. Just dusted them really. Well, should have put another coat on them, because they still seep when it gets up to temp. :mad: I have not retorqued but I am gonna try that next but not really expecting it to quit. It's ironic really, there is not a leak anywhere else for once. I really do not know what it is like to Buick that does not leak somewhere. :rolleyes:

Other that that the new motor feels like a hoss.
 
I installed my new set just prior to the BPG race in Salem. Prior to start up they were weeping water onto the PS of the block.

I through in a few of the Bar's Leaks soluble tablets and never had a problem. This is on a 109 block with aluminum (1st gen) GN-1 heads. :smile:
 
not to change the subject... I was looking at your webshots and noticed the roll bar pictures. NHRA rule book states on a full body car with a frame the roll bar must be welded or bolted to the frame. The plates welded to the sheet metal will not make it through tech. You can access the rules at NHRA.com. Look at item number 4:10 ROLL BARS " All vehicles with OEM frame must have bar welded or bolted to frame."
 
Disco Stu

i sent you a pm asking you a question off this topic..TIA........................Bob
 
GN/GTO said:
not to change the subject... I was looking at your webshots and noticed the roll bar pictures. NHRA rule book states on a full body car with a frame the roll bar must be welded or bolted to the frame. The plates welded to the sheet metal will not make it through tech. You can access the rules at NHRA.com. Look at item number 4:10 ROLL BARS " All vehicles with OEM frame must have bar welded or bolted to frame."
Click to expand...


No sh!t. Those are just cover plates.

Now if anybody has anything more to add about the original topic tha twould be great for me, and maybe somone else if they have the same thing happen in the future. Thank you Bob for your consideration to use PM.
 
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