I have a friend who is an S owner also and has my old Gen 1 UR turbo kit. He just reciently installed the 2mm Cometic HG and ARP headstuds. Upon completion and starting, the HG started leaking. So, he re-torqued the studs and it didn't resolve the problem and he went back to the stock HG with no leaks what so ever.
After all this, he contacted Cometic and he said that they told him the gasket may leak and it wasn't intended for what we were using it for in lowering compression on boosted engines.

Has anyone else heard anything or seen any other problems about this? I'd like to figure this out before I pull my head and put the 2mm HG on.
Is it true/possible that the Cometic HG isn't made for forced induction purposes for lowering compression?

 

I know this is not supposed to be done with this gasket, but I have seen it work: use some cooper spray on both sides and take it to 90ftlbs...

 

I'll look into that; thanks.

 

Spoolin, from what I have been told - speaking with John at Inline Pro is that Cometic recently redesigned their thicker head gaskets. He stated that it was a flawed design which caused leaking. FF2Skip is having some issues right now - he is not sure if it is the 2mm Cometic head gasket that I sold him (purchased from Cody@LoveFab approximately 3 months ago) or if it is the ARP Head Studs that I purchased from AtomicSpeedware and they just need to be retorqued.

 

I'm running the 2mm with stock bolts and no issues. I have heard people have issues with the ARP studs, but know of another S with the studs and having no issues. So basicly I'm saying I have no idea what the issue is...sorry

Edit: I can think of one thing, warped head or block. I'd check the tollerances on the head and get it milled if it's out of spec

 

Any thoughts as to why the ARP studs/nuts might be the cause? I don't see how a stud/nut design is that much different than the stock one piece bolt setup

 

Perhaps the ARPs were not torque down enough causing the leaks...

 

I know of a metro member that was having some issues also with a cometic gasket when he was trying to use ARP studs, I think he swapped them out for stock studs and solved the problem. Hopefully he will chime in here. I would like to get to the bottom of this before I try to install the gasket.

 

I run the 2mm gasket with stock studs and have no problems, and have also heard of people having problems with the arp's but like you all I can't think as to why.

J. R.

 

I know O'Neil had some issues. As Chad stated, we're not sure what the exact cause of my bad fortune is. I've only had a loss of compression in the first two cylinders.

My head was redone by Laskey and my short block was brand-spanking new, so I don't believe I have any warpage problems. In the next couple of weeks, things should slow down and I'll be able to systematically eliminate certain variables. Wish I had more to offer right now.

Billman250's initial thought was it was the ARP studs. John @ Inline told me before my first tuning session that I had a 50/50 chance of that gasket failing because of the Cometic-changed design. Cometic has since gone back to the original design. I still have the packaging from the gasket, so if it is indeed blown, I'll be requesting a refund or new one.