View Poll Results: Who has had heads leaking after installing .040 gaskets?
Voters: 60. You may not vote on this poll
Heads leaking after installing .040 gaskets poll.
The Cometic comes with a sealer on it (its black). The instructions specifically say do not use the copper spray as it interferes with the sealer on the Cometic. I followed Cometics instructions had no issues.
Thread Starter
Joined: Apr 2003
Posts: 2,597
Likes: 4
From: Lawrenceville, GA
I used copper spray and no leasks. Knock on wood......
Bill
TECH Senior Member
Joined: Mar 2004
Posts: 14,620
Likes: 17
From: BFE
TECH Senior Member
iTrader: (3)
Joined: Apr 2006
Posts: 6,524
Likes: 1
From: Western Burbs of Detroit
Holy old thread.
I'll add my 2 cents though. 2 years in a row 2006 and 2008 my .040 cometics began to leak from around the #2 cylinder. LGM did the work and I can vouch that they did a good prep but never the less the cometics leaked. No copper spray used, just cleaned the block and heads very well. Upon examination of the gaskets it was found in both incidents that gasket area toward the front part of cylinder #2 had imperfections at the point of the leak. A mystery I guess. Switched to gm mls and gave up a bit of compression and problem solved. GM mls were used on my 402 and 2100 miles later no leaks !!! LGM was not the problem, I guess I got 2 bad sets of cometics. ???
I'll add my 2 cents though. 2 years in a row 2006 and 2008 my .040 cometics began to leak from around the #2 cylinder. LGM did the work and I can vouch that they did a good prep but never the less the cometics leaked. No copper spray used, just cleaned the block and heads very well. Upon examination of the gaskets it was found in both incidents that gasket area toward the front part of cylinder #2 had imperfections at the point of the leak. A mystery I guess. Switched to gm mls and gave up a bit of compression and problem solved. GM mls were used on my 402 and 2100 miles later no leaks !!! LGM was not the problem, I guess I got 2 bad sets of cometics. ???
or, maybe thats just more evidences its a good idea to USE the copper spray. dads havent leaked yet. I used a liberal dosage of copper spray gasket. although the car is still tucked away in storage so far this year. but there wer no leaks at the end of the year last fall.
LS1 Tech Stories
The Best V8 Stories One Small Block at Time
6 Common C5 Corvette Failures and What's Involved In Repairing Them
Pouria Savadkouei
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph
Verdad Gallardo
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked
Pouria Savadkouei
Top 10 Most Powerful Chevy Trucks Ever Made!
Hennessey's New Supercharged Silverado ZR2 Has 700 HP
Verdad Gallardo
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes
Verdad Gallardo
Awesome K5 Blazer Restomod Comes With C7 Corvette Power
Verdad Gallardo
10 Camaros You Should Never Buy
10 LS Engine Myths That Refuse to Die
Verdad Gallardo
I used Hylomar spray, which is designed for this type of use. Just a quick dusting as it will seek imperfections during assembly. I spoke to Cometic before using and was given a thumbs up (as long as you don't go crazy with it.
I also was fortunate to have a Profilimeter from work to check Ra values and I bought a Snap-On machinist level to check flatness of the heads and the block.
I also was fortunate to have a Profilimeter from work to check Ra values and I bought a Snap-On machinist level to check flatness of the heads and the block.
