Cometic MLS head gasket Q

[shmoov69]

Guys, trying to figure out if I can reuse a brand new Cometic MLS head gasket? I just put it on and was torquing it down and the block gave way at about 70psi. So I pulled it back off and helicoiled it and hate to blow the extra $100 (and time waiting for one) if its not needed. I've never used them before, but searching LS1-tech posts say "ok" for the most part.
Anyone here with experience with these?
thanks!

[benno505]

i have them on my 505, i was told you cannot reuse them as once they are compressed they should not be reused, i am not 100% sure why they cannot but i was told this, hopefully someone can chime in and say why they cant

[Ron Sutton]

Hi guys,

The reason they suggest not reusing them is ... as a multi-layer steel gasket ... it compresses as the bolts are torqued ... and if torqued correctly the gasket is compressed shy of being in a solid state. It still has a degree of "springyness" to it that helps it seal.

If you were to reuse it, after some, many, most or all the bolts have already been torqued ... and you torque them all back to what you think is "exactly the same" there is still a margin of error that could produce "spots" where the gasket was compressed more before ... and now doesn't have the proper compression.

At the race track, I have re-used them, but added some torque to my specs, to insure I was compressing the gasket both evenly & more than before. Of course this is risky, as you could overload a head bolt/stud or pull the threads out again. At the track, we had more to lose by not running the race & that made the risk worth taking in that situation.

But in your situation, I'd say the risk isn't worth it & simply buy a new gasket.

.