cometic headgaskets install dry or light coat of copper spray

[BIGPSI]

as title says heard guys doing it both ways,which is best? also read turbo Ls guys using hylomar spray. i am gonna install new cometics and want your guys input. Thanks Brian

 

[Grumpy]

as title says heard guys doing it both ways,which is best?Thanks Brian

you have answered your own question.

 

[DR BOOST]

put some black rtv around the oil drains in the top corners...even between the layers

 

[BIGPSI]

you have answered your own question.

so which way,dry or light coat of copper spray? i have never used these before and wanted feedback from guys that have used them before

 

[williamsGN]

3 cometic installs, copper spray & some rtv around the water passages.. no leaks.

 

[BIGPSI]

3 cometic installs, copper spray & some rtv around the water passages.. no leaks.

thanks

 

[turbodave231]

I drill out the rivets, wash the three pieces with dish soap and hot water and spray every other side with Hylomar spray. Surface finish on the deck and heads must be ultra smooth too.

 

[Ttype6]

Surface finish on the deck and heads must be ultra smooth too.

This is the only thing you need to be concerned about. Then put them on as is.

 

[turbofabricator]

I spray both sides of each layer with copper coat. (remove rivets to accomplish this) I have also installed them dry (on my own car and they seep oil) Hylomar would also work well, too.

 

[Jerryl]

I drill out the rivets, wash the three pieces with dish soap and hot water and spray every other side with Hylomar spray. ........

Here are some pictures of the fresh Cometics.

 

[BobbyBuick]

This is from Cometics website

Why does Cometic recommend MLS gaskets to be installed dry?
Cometic Multi-Layer Steel (MLS) head gaskets go on dry because they are coated with a sealant. Each MLS head gasket is coated with a .001" thick viton rubber that is bonded to the outer stainless steel layers. Adding an additional sealer can hinder the performance of an MLS head gasket.

I reused a set when I had the cam debockle .I installed dry 1 st time and dry 2nd time ,ran the car (heated and cooled with no water 3 times for about 5 minutes .Let it cool and filled the water jackets no leaks .The first time didnt do this and it leaked out the back of the head until I installed the pellets 2nd time no pellets

 

[johnplogii]

I put a thin layer of silicone around the water ports & oil return passages & install. The smoother the surfaces the less your chance of any problems.

 

[Jerryl]

This is from Cometics website

Why does Cometic recommend MLS gaskets to be installed dry?
Cometic Multi-Layer Steel (MLS) head gaskets go on dry because they are coated with a sealant. Each MLS head gasket is coated with a .001" thick viton rubber that is bonded to the outer stainless steel layers. Adding an additional sealer can hinder the performance of an MLS head gasket.

I reused a set when I had the cam debockle .I installed dry 1 st time and dry 2nd time ,ran the car (heated and cooled with no water 3 times for about 5 minutes .Let it cool and filled the water jackets no leaks .The first time didnt do this and it leaked out the back of the head until I installed the pellets 2nd time no pellets

Cometics are the experts on their gaskets, period.
What they fail to mention in their ad (imagine that) is their quality control, i.e "Dirt between the layers". LOL!
Just HATE leaks and am unwilling to roll the dice . . . . especially after I saw all the dirt between the layers.

I have also read many posts about dry installations with GREAT success.
IMHO, If you have any reservation about the RA, spray the gasket(s)! . . . Hylomar was my cheap insurance!

 

[GARY HARVEY]

Block and cylinder head surfaces need to be clean and dry.

Chase the threads with a bottom tap and flush with alcohol then blow out the holes (even a new block).

Grain alcohol and a clean wipe until there is NO sign of whatever on the wipe.
Lastly.. a flame heat source (flash the surface) to remove any residual oil then wipe one last time.

*Very Important to hoist a few with the remainder of the alcohol* (OJ works well).

Insure both cylinder head and block are at the same temperature (little warm is positive).
First torque sequence is 50% then plust 10% until the last 10% which I split at 5%.

After a reasonable number of heat cycles re-torque at 100% for insurance (nuts should not move)
TORQUE TO SPEC.. not over. (if, you have ANY additional torque on the last pass.. something is wrong)

Note: if you have followed this [anal] procedure and blow the gasket, it's not the headgasket
that is the problem.

I use a single light pass of copper coat and allow the gasket to live in an oven at 200 degrees for 3 hrs.,
or air dry for a week.

 

[BobbyBuick]

CLEAR AS MUD YET!

 

[Phoneguy]

Do yourself a favor, install studs with the Cometics.

Bryan

 

[Grumpy]

CLEAR AS MUD YET!

Hell ya !!!!

 

[williamsGN]

Studs (doing the 5 torque sequence on them that ARP recommends on their website), copper sprayed and hung on a wire for a few minutes, cleaned the stock finished heads and deck with brake cleaner, applied plain RTV around the coolant passages. Torque in sequence in increments 50/70/85 using ARP lube.
3 jobs on cars, no leaks.

You can do whatever voodoo ritual you think will help them seal if you wish

Cometics website I would say is towards N/A motors, not running 20+ PSI

 

[BIGPSI]

Do yourself a favor, install studs with the Cometics.

Bryan

already have studs. i have been doing the dbl stack steel shim with ge1200 that worked great on my last motor,i switched the heads to a different motor and could't find ge 1200, some guys said use ge4000ultra glaze so i did, i had a little detonation on the way home from the track last year racing a corvette, I won but the temp dropped on the way home and i was lean. so i have motor apart now and the ge4000 didn't seem to work well,and my headgaskets looked fine. so i decided to go with cometics,just trying to get some input thanks

 

[turbofabricator]

CLEAR AS MUD YET!

<< *Very Important to hoist a few with the remainder of the alcohol* (OJ works well).>>

Especially THIS part. Can't argue with any of this. Good advice, all. One note about copper coat.........On the last StageII I did, on first oil change after break-in, there was alot of copper in the oil. I was CONCERNED to say the least. After the next change there was nothing. It was from the exposed gasket in the lifter valley. This engine made 125+ psi of oil pressure at idle (fixed that too, but that 's another story that was posted) So if you spray the gasket with copper coat, don't freak if you see some copper particulate matter in the oil. It's just being washed off the gasket.