Questions about Cometic copper headgaskets

[guyd_15]

We're getting ready to do some upgrades (Super 70, custom cal, blah, blah, blah) on my son's CSX-T. And we are wondering if a copper gasket is a good choice. We will be using head studs and just want to avoid those pesky gasket changes. Are there special preparations needed? To those that use them, what thicknesses are you using? We're contemplating the stock thickness. We would like to hear your personal experiences.
And btw does anyone know if Cometic's new Phusion gasket is available for our cars?
Guy

[guyd_15]

for some reason this didn't show up in new posts

[GLHSKEN]

Guy, That's where I saw it. New posts. If you post it it will not show up in your new posts. Others will see it. When there is a reply, like now, you will.

[cordes]

I have run 22 PSI on a MP gasket, and I know that others have run 30+PSI with one.

Some think of the MP gasket to be like a fuse. It will blow before your short block does type of thinking. I'll buy it.

[contraption22]

I really like my cometic gasket. I am actually using the same gasket for the 2nd time and it seals great.

[GLHSKEN]

I'll always ruyn MP's. Seen them hold 460+wtq... In My car's case it held too well. Should have blown but I melted a wiseco.

[ssheen]

You melted one of your newish pistons Ken?? How you do that?

[GLHSKEN]

cal issues. cal was made for a stock head.. I threw a menegon head on and fuel was not adequate!!! And I did not let out... man was the car a rocket... Up till she melted :) 15 psi Boost I ran a 14.17 on a 14.1 dial in at 107mph (street tires)

[contraption22]

I seem to have a similar problem Ken. In the process of tearing down now to see if the piston is damaged, but it likely is. On my old custom cal i had way too much timing and probably not enough fuel. On the tuner's advice and against my better judgment, I let the EGT's get up to 1600 and the gasket let go on #1. The head actually melted a little but the piston looked good from up top so i didn't pull it. But since then, number 1 has been down on compression, even with a new head. Hopefully I will not need a new piston, because mine are old FM JE's. I don't know that I can still get one. Might be needing a set of 4.

[Ondonti]

What are the normal cometics made out of. I have to buy a 95mm headgasket for my 3.0 and the only ones are a $268 for the pair made by who knows, and then a 95mm pair of cometics for like 160


But regarding running a thicker or just a stock gasket, you should know what your goals are, and knowing those goals, you should figure out what compression you need based on the boost and octane you want to run. I dont know if lowering the compression with a thicker gasket will accomplish anything, if the pistons are still going to blow even with lower compression. I Dont like the 2nd quench area around the spark plug on 8v's and I dont know if opening up that gap more is going to prevent detonation.

[BadAssPerformance]

What are the normal cometics made out of.

MLS = Multi Layer Steel

I think I recall reading SMP using this to 600+ HP w/o O-rings :thumb:

MP gaskets dont last in my car past 25psi... BTW, turbo size * boost = headgasket life

looking to get a Cometic now...

["Top Fuel" Bender]

anyone know if Cometic's new Phusion gasket is available for our cars?
Guy

I contacted them 6 month's ago this
at the time they did not
I talked them in to looking into convincing them that the neon/srt's use the smae bored dia. and cometic already made the gaskets
I got a phone (very surprising) saying they have considered it but they would be $300 :faint:

[contraption22]

What's different about the Phusion gaskets?

[guyd_15]

It's an piston aircraft type gasket, the difference is the fire rings are filled with compressed gas. With the ring inflated the pieces being sealed can move around and the fire ring doesn't loose it's seal. It doesn't promote the movement it just helps keep it sealed.
Guy