98 vs 99 head gaskets

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Jun 24, 2005 | 12:16 PM

#21

01Blackerado

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From: Fairfax, VA

Quote:

Originally Posted by PREDATOR-Z

GM MLS are thicker than graphite. .060 compressed. Not good for quench purposes.
Cometics are the good ones but good luck finding any in stock (3>4 week backup order)

thats cause I just bought their last ones a week ago

Jun 24, 2005 | 05:21 PM

#22

oange ss

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From: Texas

anybody ?

Jun 24, 2005 | 05:37 PM

#23

SPANKY LS1

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From: Seneca, SC

Quote:

Originally Posted by oange ss

what gaskets would be good for quench ?

Quench is different from engine to engine, there is no way for anyone to tell you what gaskets you need. Depends on how far in/out your pistons are. For example, if your pistons are .008 out, then you would want a ~.043-.048 gasket (general consensus is that "optimal" quench is ~.035-.040. Quench area is the height of the piston top to the bottom of the head, basically head gasket size +/- the piston deck clearance) Make sense?

Quote:

Originally Posted by oange ss

dont wanna go to small to help keep compression down, thanx

Thinner gasket=more compression, thicker gasket=less compression. You can't have it both ways, so to speak. If you want optimal quench, you will need a thinner (than stock) gasket, and as a result, will have a higher compression ratio, as well as less P to V clearance.

Search for "quench", it has been discussed in depth on several occasions...

Shawn

Jun 24, 2005 | 05:57 PM

#24

oange ss

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From: Texas

I understand the quench/compression deal..just didnt know how to calculate for quench ...thanx for the info , I really appreciate it

Jun 25, 2005 | 12:36 AM

#25

guinness2

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From: Port Saint Lucie,Fl

Quote:

Originally Posted by 2xLS1

Actually, I took that pic and it is of a head off of my 99, casting #853. Any 853 casting will have the notch and they were used through 00 MY. The GM graphite gasket will not have a notch there. The problem is if you use the 02+ GM MLS gasket with heads with the notch, it will leak coolant there. The graphite gasket seals around that notch and the GM MLS does not.

I have a set of 853's chopped down .030 will I be ok with the MLS gaskets???

Jun 25, 2005 | 01:04 AM

#26

guinness2

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From: Port Saint Lucie,Fl

Quote:

Originally Posted by 2xLS1

My 00 853's have no notch, but I also have a set of 99 heads that do.

Jun 25, 2005 | 03:08 AM

#27

PREDATOR-Z

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From: BFE

I was told by a sponsor here that the notch is around .060 deep. So unless it was welded in (which a lot of them do to be able to use MLS), you'll have to use graphite.

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