Arp torque specs and Cometic gasket question

Stephen

6,846 posts · Joined 2000

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#2 · Aug 6, 2006

I do not believe the cometic headgasket is re-usable. I do know from personal experience the mitsu metal IS re-usable. I believe the fasteners without lube should use oil as lubricant and are about 10ftlbs tighter.

 

V

V8s_are_slow Discussion starter

1,068 posts · Joined 2002

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#3 · Aug 7, 2006

What weight oil?

 

Asmodeus

11,002 posts · Joined 2002

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#4 · Aug 7, 2006 (Edited)

I've seen one used 4 times now.
cometic

Due to problems it had to come apart a few times in the early stages.
Its now seeing 28+psi from a 60-1.

Without a hiccup.


use straight 30w or higher.
I went to 110 then on the retighten 115 on the head bolts.
in 10lb increments from 40lbs
in sequence.
(using mitsu 4 layer)
not the slightest problem yet.
(I didn't have lube either.)

MAN were my arms tired.

 

K_Mans_TSI

16,495 posts · Joined 2001

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#5 · Aug 7, 2006

torque specs are signifcantly higher with just oil....i know they recommend 80 with the lube and over 100 without...that's for normal values, most guys will torque closer to 100 with the lube on larger turbo applications i have no idea what that would be without lube.

 

4SFED4

1,286 posts · Joined 2002

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#6 · Aug 7, 2006

I use moly lube and torque to 85 ft/lbs in 20 lb increments.
2nd I start the engine and let it run to operating temperature low RPMs(<3K) no driving/load.
The I let it cool to the touch, loosen the each fastner a 1/4 turn individually and retorque it to 85 ft/lbs in the proper sequence.

I have used that method on Cometic, Mitsu 4 layer and SCE copper gaskets. I have tried to torque the cylinder head as high as 120 ft/lbs(same method/procedure) and it makes no differance.
When the engine reaches its threshold of boost and timing the head will lift. With conservative timing I have had no problems with any of the above gaskets. I even drove on an almost daily basis with a SCE plain Copper only using Permatex copper coat to seal, no coolant seepage or loss.