Ever use Cometic Head Gaskets?

[AMXguy]

I got my Cometic gaskets today, wow. shouldn't you use some kind of sealer or something with a metal shim gasket like this? I guess they work but I don't like the idea if nothing but metal shims trying to seal tight.

 There were no instructions.

[dodj]

I have never used them cause I don`t have aluminium heads (yet), but from what I`ve read, they are a multi part gasket that allows the aluminium head and the steel block to expand at their different rates and stay sealed. Never read anything about using a sealer on them.

[quagmire]

I have them, don't use sealer.  Virtually all bimetal or all aluminum engines nowadays use these gaskets, they are very strong and reliable.  None of them require sealer, it's use is actually discouraged and can cause problems.  IMO, these gaskets are superior to most any other style of head gasket.  Some say block surface finish is critical, but my mating surfaces and many others are not specially finished with no problems.  No OEM requires refinishing during head resealing either, unless they are warped of course.  As long as the surfaces are flat and proper torquing is performed you should be just fine.  I've even seen numerous people reuse these gaskets, but I'm not quite brave enough for that!

[gkring]

I have them, don't use sealer.  Virtually all bimetal or all aluminum engines nowadays use these gaskets, they are very strong and reliable.  None of them require sealer, it's use is actually discouraged and can cause problems.  IMO, these gaskets are superior to most any other style of head gasket.  Some say block surface finish is critical, but my mating surfaces and many others are not specially finished with no problems.  No OEM requires refinishing during head resealing either, unless they are warped of course.  As long as the surfaces are flat and proper torquing is performed you should be just fine.  I've even seen numerous people reuse these gaskets, but I'm not quite brave enough for that!

Ditto what he said. I don't normally use them in stock applications because they do work so well and I normally like the head gasket to be the fuse in those situations. For the racecars they are great. If you need sealer then something else is wrong. I will reuse them 3 or 4 times as long as they look okay. At $100 each it is nice you can reuse them. You can also get them in many thicknesses to make up for a milled head and tweak compression ratio.

[AMXguy]

Thanks, yes I needed to make up for .020 of lost head and block is why I bought them. my heads and deck are fresh and smooth, I just get the willies trusting metal to seal metal but OK.

[Chryco Psycho]

I use them all the time , Best gasket made IMO
never used a sealant though