Fed up with Cometic MLS HG's.... Any suggestions?

95CobraMike

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Apr 12, 2004

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Lima OH

Dec 29, 2005

#1

• Dec 29, 2005

• #1

I have been through 3 sets of cometic multi-layered steel head gaskets and keep having leaking issues... not worth the $80 each in my opinion

What other options are out there as far as HG for a SC'ed 306? i need it to be relativly thick to keep compression low

Copper?

Thanks

 

BlackVert

15 Year Member

Oct 3, 2003

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Bethesda, MD

Dec 30, 2005

#2

• Dec 30, 2005

• #2

i'm confused ... do you keep blowing head gaskets or something?

if so, maybe the problem is the tune, not the gaskets ...

 

95CobraMike

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Lima OH

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#3

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i keep having leaks... not really blowing them, i dont know that they seal from the beginning

 

W

wytstang

Mustang Master

Mar 14, 2004

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Summerville,SC missing South Fl. weather :(

Dec 30, 2005

#4

• Dec 30, 2005

• #4

Have you considered torquing(sp?) the heads down a bit more.....say like 5ft/lb extra. That wouldn't be enougn to really effect CR.

 

Killercanary

The car that set the bar.

Founding Member

Nov 29, 1999

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Altoona, PA

Dec 30, 2005

#5

• Dec 30, 2005

• #5

Did you follow cometics recommendations and make ABSOLUTELY sure the dck was straight? Thsi normally entails having the block decked.

My cousin has run ROL thicker style head gaskets on his kenne bell SC'd 94 for years without a problem.

 

Rick 91GT

Mustang Master

Nov 29, 1999

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Dec 30, 2005

#6

• Dec 30, 2005

• #6

Did you have the proper RA finish on the block? The Cometics are reusuable just drill or cut a couple of the rivots and fan them out, clean them very well.

I spray all the MLS gaskets I use with a gasket sealant that Mopar uses, they actually use a lot of MLS gaskets on factory cars. I also torque the studs down to 105ftlbs, this is with a 1/2" stud. You can get the spray at any local Chrylser dealer, it's in a black can and the stuff is yellow $7.

They will not seep coolant then....

 

95CobraMike

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#7

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Last time i did the gaskets, i had the block and the heads checked for plumness... Both were fine. i cleaned the heads and block with thinner. i also took the rivits off of the HG's and cleaned them up inside and out (reused)... using ARP head STUDS torqued to 90 ft/lbs

 

OrangeMustangGt

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Cape Cod, MA

Dec 30, 2005

#8

• Dec 30, 2005

• #8

i have always had problems with cometic, but not with cars

When i put a 11:1 compression wiesco piston in my yamaha raptor, it came with cometic headgaskets, and right after, i got a blown HG, whell i replaced it with another cometic thinking it was a bad one....nope, blown hg again. So, i just stuck a stock yamaha one in, ane never a problem again....soo i have never been impressed with them.

 

ROLLIN5.0

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Nov 19, 2004

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Tulsa, OK

Dec 30, 2005

#9

• Dec 30, 2005

• #9

Copper will leak/seep too. Get the spray, and up your torque a little.
Brandon

 

95CobraMike

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Dec 31, 2005

#10

• Dec 31, 2005

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what is in this spray stuff you folks are talking about?

 

Rick 91GT

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Nov 29, 1999

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#11

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Go to your local Chrysler dealer, ask for the gasket spray they offer. It is in a black can, the stuff is yellow and nasty. I learned this trick from a few racers, never had any issue afterwards.

Are you sure it is leaking at the gasket and not the studs?

 

blksn955.o

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st.louis mo 314

Dec 31, 2005

#12

• Dec 31, 2005

• #12

Not to steal the thread...

A buddy of mine has a set of AFR 185's and wants to run cometic HG's on his 351, his AFR 185 have the "eyebrow" and they say they can cause a coolant seepage(sp?) issue with cometic gaskets. He is wanting to use cometics...any advise on this?

 

KBCobra95

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Aug 28, 2005

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Dec 31, 2005

#13

• Dec 31, 2005

• #13

I used cometic heads gaskets on my kenne bell'd cobra with afr 165's and no problems whatsoever. I even called cometic before putting them on and asking them if I should put some sorta sealant on them. They said that I did not have to. so I didnt and no probs so far

 

Rick 91GT

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Nov 29, 1999

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#14

• Dec 31, 2005

• #14

I hae used them on the eyebrow style heads with no issue, I use to install them dry and use the sealant when I had to re-use a gasket. Now I spray them on the first install to prevent any issues, so far no problems.

 

95CobraMike

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Lima OH

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#15

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Rick 91GT said:

Are you sure it is leaking at the gasket and not the studs?

Click to expand...

what is the diffrence? if its leaking around the stud, isnt that also a gasket issue? or are you talking about thread sealant? I have always used thread sealant

 

Rick 91GT

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Nov 29, 1999

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#16

• Dec 31, 2005

• #16

The gasket could be sealing and the coolant could be leaking up through the studs, even if you used the ARP or a simialr sealant. Look closely and see if the coolant it on the nut of the stud, it may be that....

I went through this on 2 stock blocks lately when using ARP teflon sealant, everyhting was clean, etc..but based on the tolerance of the block and studs it is possible. ARP advised me to use Permatex..lol and or run some Alumaseal through the motor.

 

95CobraMike

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Lima OH

Jan 2, 2006

#17

• Jan 2, 2006

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thats what i used on the studs...permatex

i dont know i guess i can give them another try and use some of that gasket sealer stuff and get a good tune...

 

94TURBO5 O

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Mar 14, 2004

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Jan 2, 2006

#18

• Jan 2, 2006

• #18

I never paid for the Cometics but came close everytime. When I blew hg's with the first blower install I used Fel-Pros. My latest pair came from NAPA cheap ones (OEM) but have lasted through the S-Trim, KB and the Turbo (so far).
Oh and the sealer stuff I used ARP stuff from Summit (thread sealer and lube)

 

95CobraMike

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Lima OH

Jan 2, 2006

#19

• Jan 2, 2006

• #19

i dont know what to do this time..... thinking either cometics again or copper or maybe felpro.... def. a tune....maybe some of that gasket sealer... probably some aluminum heads!!!

 

Rick 91GT

Mustang Master

Nov 29, 1999

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Jan 3, 2006

#20

• Jan 3, 2006

• #20

Coppers are a huge PIA, I'd stay away from those.

If you want a MLS gasket Cometic and Fel-Pro both make them, if you want a good performance gasket use a Fel-Pro 1011-1.