Received the latest Cometic MLS

I am not that impressed.. I was not happy with the old one because it bowed in one spot this one is bowed all over. I expect the damm thing to be flat and it's not. It looks like a Pilsbury DoughBoy Puff Pastry

What I noticed is the ridges appear more pronounced.There are additional small holes near the bottom.

 

My old one wasn't bowed at all.

Doesn't look much different

 

The advantage to torquing down your head bolts is that the HG will then be flat. Looks ok to me.

 

looks ok to me as well

 

Expectations are over-rated. Too much to list.

 

Looks good to me as well. The bowing shouldn't be an issue as when torquing it down that will all flatten out. If it were bent or creased, then that would be a problem.

 

i sometimes see the term cometec "fusion" is there more than one type of cometec gasket ?? can you guys set me strait ?

 

Cometic Phuzion gaskets use separate gas filled cylinder sealing rings. The gas expand with heat so sealing should increase with heat.
Only downside is the gas rings aren't re-usable and cost like $57 each..

 

Thanks for the input. I've heard that too from several creditable sources.

 

The two I have had were flat, but like others said once installed I don't think it will be a problem.

 

extra $230 yikes how much is the basic comtec $140?
kind of seems half way... milling for the gas ring and then CNC for rubber orings for oil and water then no gasket would make me feel pretty studley

 

This is just sloppy tolerancing (by Cometic) on the 3 holes for the joining brass rivets (or whatever that type of fasteners are called). I have seen the same thing to a much lesser extent and installed the MLS gasket with success.

If I were you, I would either:
1. Have it exchanges for one that is much closer to being flat
Or
2. Drill out two of the three rivets, insert a wood pin in the two open rivet holes, verify that all the other holes are reasonably well aligned and install the gasket.

The rivets are outside the mating surface and are only there to help installation. However as it is now the risk of the fire-ring sliding out of position during installation is increased.

Btw, when you install the gasket, you may find that the holes for the aligning dowel pins (in the block) are badly toleranced too.

Laust

 

Hi Laust,

Still working on my motor been 3+ years now..
Four head gasket install attempts have identified poor machine shop block decking. Attempting to fix the problem by sanding out the machine tool ridges by hand using 600 grit paper and steel flat sanding block.

Am I insane? You Betcha!!


I did take your advice talked to Mike Lindsey he is sending me out HG today that is flat..

Thanks for the advice glad to see you are still active on Rennlist.

-BB

 

If your block/head are not perfect i would not use a MLS gasket. They are IMO better gaskets for high cylider pressures but need perfect surfaces to seel properly. New engines that use MLS gaskets from the factory have a very specific finsh done to high tolerances.

 

We had a conversation with Cometic but neglected to pass the information along to Buckaroo. Sorry about that! Cometic says that's normal and they are all that way. The other 25 gaskets we received with that one all do that. They press flat and align when installed.

As for sealing, they do call out for a fine machine mark on the surfaces. The Viton coating on the gaskets is only .001" thick so your machine marks need to be pretty fine. We sand the surfaces with Emory before assembling to knock any sharp peaks off the surface.