Head Gasket

[Big Jay]

The whole high performance scene has gone to the MLS ( Multi layer steel) head gaskets.

This is what comes from the factory on all the new stuff, Busas, ZX Kaws, etc.

The big nitrous drag bikes have gotten away from o'ringing and copper gaskets, because these MLSs will seal up even better.

Unfortunately in the GS world, they are not made in std bore. She smallest we carry is 75 mm.

[Nessism]

Big Jay, If it was your bike would you use a modified stock GS1150 head gasket for a Wiseco 1166 application or would you use the MLS gasket from Wiseco? I've read mixed results on this forum about MLS style. (I have one of each but haven't decided which way to go)

You might want to look up Jim (Posplayr) for feedback. I seem to remember him ranting about a design flaw in those gaskets, after experiencing repetitive leaks tying to use them.

[OLDENUFF]

I used the MLS design in both my 750/850 and 1100/1168 rebuilds. No problem with either.

[Nessism]

Yea Jim's post was the one that put the fear of MLS in me, but Jay seems to be saying MLS is what everyone else and the companies are doing. I'd like to hear both sides. Do you not use gasket sealer on the MLS type?

MLS is a type, and works well if properly designed and made. Jim suggests the Cosmetic gasket for that particular application is poorly designed and has a leak path. This has nothing to do with MLS, just that particular gasket. And I don't think you are supposed to use any sealer on head gaskets, although I'm sure some people do and live to tell about it.

http://www.thegsresources.com/_forum/showthread.php?t=171295

[Big Jay]

I forwarded a link of this thread to Mike at Cometic Gasket. Below is a portion of the answer he sent me.


"On our first few mls gaskets we did have an oil leak issue on stock
applications. Our gaskets were built off of the Vortex heads and did not
have provisions for stock oiling passage seals, as the drag bikes almost
exclusively were using external oiling. Once we caught this we went back and
added embossing for the stock oiling passages and the issue was fixed.

I think the bigger issue at hand is that people don't understand how mls
gaskets work. They require an ultra smooth surface finish in order for the
viton micro-sealer to work; they also don't seem to understand that the
direction that the embossments face is not nearly as critical as the finish.

Sealers are not necessary with MLS gaskets. The reason that the sealers
should not be used is they can cause issues with the clamp load on the
gasket. If the surface is rough adding sealer is not going to fix it. It has
to be surfaced to a 50RA or smoother finish."