I know that that somewhere around 45-50 psi of boost the stock gasket cant take it but what Ive heard is that there is some company that makes a gasket that lets you get away with more boost. Is it a myth or is it true?

 

I heard a Cometic HG and ARP Studs will hold up to 80psi.

 

I want to see the long term effects of the cometics. I have heard of several failures at relatively low boost. So time will tell.

I run them on the Pontiac as I can get the thickness and hole diameter I want.

Dave

 

That was the rumour when they first came out, but I think that was put to rest when a high percentage of those gaskets failed fairly quick. I have one in the basement, it won't be going on my truck anytime soon.

 

I put two on my truck one on a buddys truck and thay all blew DONT PUT ONE ON YOUR TRUCK !!!!!!!!!!!

 

They blow because people don't prep the block. To do it right, you have to have a smooth head AND block. I forget the toleranaces. The cometic is a MLS gasket, just like whats being used in the common rail's from the factory. Notice that all they need for higher boost is studs? To get the cometic to work, the block has to be pulled and prepped, and the average joe just isn't willing to do this. I know i'm not.

 

Prep work or not.........they fail

 

Interesting.....
Did they make changes in them since their last run?
Are you retailer of them?

 

For MLS gaskets to work, the block and head have to be flat. But I think the head issue has more to do with lack of clamping force area as opposed to clamping force at a specific point.

Meaning, if we had one more stud/ bolt around the perimeter of the cylinder, it would do wonders for gasket failures. Although there is nothing we can really do about it.

And my use in a high compression V-8, even with squeeze does not compare to the typical diesel motor.

Again, JMO.

Dave

 

Nope, just a sponge..lol

 

Whats the deal with copper and aluminum HG? I have heard that those are the best HG you can use for high boost. Any thoughts on copper or aluminum???

 

I've heard that Schied has their own brew of an MLS gasket with fire rings built in, I believe it's a .30 over(which means you will have to get you're head decked. MikeD is running it with 14mm studs, he is running high boost and a lot of squeeze with no issues. If you run a 12mm stud, you will probably have to invest in some ARP 625's. Im thinking about doing it with the 625's( I am on borrowed time with my stock studs and gasket).

 

At the time that I beta tested the Cometic MLS, Schied said 14mm studs were mandatory with their gasket

 

Don't really see why, the 625's can almost torque down as much as a 14mm. Maybe, they were trying to play safe during beta stages?

 

Yeah I donno?
I had spent enough at that point just prepping for the Cometic that I didnt want to get into the extra expense of more machining than I already had and I already had the 12mm studs. I think the Schied gasket will be a pretty good piece but I don't know that it will hold anymore than a quality o-ring job and it will cost at least 3 times the money.