Head gaskets
Thread Starter
Pro
Joined: Sep 2014
Posts: 513
Likes: 11
From: Hills of Tennessee TN
Head gaskets
I'm about to do my first supercharger install on a C5 stock bottom end LS1 (stock bore and stroke). I have the standard baby blower cam. long tube headers , etc. I'm going to be using ported 317 casting that have been surfaced to bring compression back to LS1 spec. I don't know exact comp. yet as I haven't CC heads yet and I will be doing some chamber modifications. But, in the end my compression should be between 10:1 and 10.5:1 after final head work and surfacing. And, I don't plan on going above 10 PSI on boost as this is a 90% street car.
You FI guys with experience in this area, what head gasket would you suggest is the best for my setup. I know thickness affects compression, etc.. I will determine thickness after heads are complete ad CC'd. What I am asking is brand, type, etc. Is original GM best? IF you are referring to a particular gasket please give Part # if you have it.
Thanks
You FI guys with experience in this area, what head gasket would you suggest is the best for my setup. I know thickness affects compression, etc.. I will determine thickness after heads are complete ad CC'd. What I am asking is brand, type, etc. Is original GM best? IF you are referring to a particular gasket please give Part # if you have it.
Thanks
Melting Slicks
Joined: Jan 2008
Posts: 2,590
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From: Nathalie VA
St. Jude Donor '15-'16-'17-'18
Safety Car
Joined: Apr 2000
Posts: 4,326
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From: Weatherford, TX
I got some Ls9's once, but ended up returning them. They didn't match up well with my cylinder walls or the combustion chambers. I've been running stock LS1 3 layers (GM 12498544), and they've held 25psi boost on once combo, and 20psi/150 shot on my recent combo. I don't see what an LS9 gasket buys you for an LS1/LS6 block.
Melting Slicks
Joined: Jul 2004
Posts: 2,844
Likes: 144
From: Northern Ireland
LS9's are a better design than the regulars, plain and simple. It's well proven they do hold better where others have struggled, including the likes of Cometic.
Unless you are overly pedantic about bore sizes for your gasket, there really isnt any need to pay anything over what LS9 offers...and often paying more doesnt get you better anyway.
Of course regular GM MLS gaskets work superbly too. Up to around 1k, for most part they work fine too anyway and are cheaper again.
Unless you are overly pedantic about bore sizes for your gasket, there really isnt any need to pay anything over what LS9 offers...and often paying more doesnt get you better anyway.
Of course regular GM MLS gaskets work superbly too. Up to around 1k, for most part they work fine too anyway and are cheaper again.
Instructor
Joined: Mar 2015
Posts: 108
Likes: 3
total bs ..if this were 100% true, why not add 16 layers for even more "sealing power"..?
I had both ls1 and ls9s and they both had issues.... ofcoasre i suppose they do work on mild low power engines that most run here.. so i can see why alot like them..
the real sealing comes from having your heads 100% true and right.. thats plain and simple..
I had both ls1 and ls9s and they both had issues.... ofcoasre i suppose they do work on mild low power engines that most run here.. so i can see why alot like them..
the real sealing comes from having your heads 100% true and right.. thats plain and simple..
Melting Slicks
Joined: Jul 2004
Posts: 2,844
Likes: 144
From: Northern Ireland
total bs ..if this were 100% true, why not add 16 layers for even more "sealing power"..?
I had both ls1 and ls9s and they both had issues.... ofcoasre i suppose they do work on mild low power engines that most run here.. so i can see why alot like them..
the real sealing comes from having your heads 100% true and right.. thats plain and simple..
I had both ls1 and ls9s and they both had issues.... ofcoasre i suppose they do work on mild low power engines that most run here.. so i can see why alot like them..
the real sealing comes from having your heads 100% true and right.. thats plain and simple..
And no, sealing is a combination of all factors. If you naively think it is only about the heads being 100% true as you put it....
What about studs, bolts, block face etc ?
everything needs to be right, and of course if either build or tuning is bad, that person can destroy even the best sealing option very easily.
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Joined: Apr 2000
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From: Weatherford, TX
If pedantic means wanting my bores and chambers to match within .2", then I'm guilty. I could see using LS9's for an iron block or something with a >4" bore, but otherwise not a good match for LS1/LS6. I'd like an Ls9 crank, dry sump and oil squirters too, but probably better off just getting a ZR1. 