tech@WS6store

iTrader: (2)

The 12498544 are a multi layer steel gasket (mls) just like the ls9, the ls9 gasket just has more layers but also a larger bore size. Quite a bit larger when talking about bore sizes actually. ls1 mls gasket has 5 layers ls9 has 7.

70c10

iTrader: (1)

How much boost can the stock LS1 MLS 5 layer gaskets handle?

tech@WS6store

iTrader: (2)

There is no actual measured amount honestly and no gm spec. I've seen as high as 20lbs but im not telling you to run 20lbs and at 21 they fail. They were pushed pretty far before the ls9 was around so take that how you want.

70c10

iTrader: (1)

Thanks for all of your help. I'm only planning to run 10-12 pounds with arp head bolts. I'll probably get the 5 layer ls1 gaskets with the correct bore size. Having the large gap with the ls9's makes me nervous regardless if everyone is Doing so. Do you have an online store where I could purchase?

tech@WS6store

iTrader: (2)

Yes....post #5

But here is a direct link also

http://www.ws6project.com/user_stor/catalog/2002-ls1-gm-mls-head-gaskets/

SethU

Boost wouldn't be the indicator I'd personally use.

Gasket failures are more closely related to cylinder pressure, which would be better indicated by torque.

An overly aggressive tune, even on an NA engine, can create a peak or spike in cylinder pressure and cause gasket failure.

However, if state of tune and fuel is satisfactory, my gut feeling is you could push the LS1 gasket north of 30psi and be just fine... If you wanted to put a PSI figure to it. Rough guess though.

And, a bad enough oopsie in the tune will thrash an LS9 or any other gasket just the same.

70c10

iTrader: (1)

I ordered the 12498544 but they are only 3 layer please explain.

Game ova

Tr6 here. Not making 4 digit power..... but no issues thus far.

tech@WS6store

iTrader: (2)

Gm may have changed their manufacturer (and the amount of layers) but they are still a very sturdy heavy duty gasket.
I have a set i pulled off a 5.3l ill check layers on them tomorrow.
There wont be any issue though otherwise

Dian

steve, why do you use projected plugs? do you feel they work better?

stevieturbo

That's a bit like asking why do I use Denso at the minute instead of NGK.

I've used both, but at the minute the plug I'm using doesnt come in a non-projected nose.

I see no real difference one way or the other. Use whichever comes in the style, heat range, etc etc that suits your needs.

But I would totally disagree with anyone who says people must use a non projected nose plug.

ls3fox

those are not ls9's

70c10

iTrader: (1)

I know, I ordered ls1 MLS gaskets but was under the assumption they were 5 layer according to everything I've read.