URG8RB8

I think you are asking for trouble going with MLS, as George said, stock is plenty good for your application. I am running 20 psi on a 125,000 mile totally stock short block. (On E-85)

Dougs951S

on 22 psi burning corn juice, stock bottom end with (new) stock head gasket. As Lart mentioned, its all in the tune.

OnlineAlias

Cool, stock it is. Thanks for the help...

George D

The cometic is overrated, usually leaks unless you have two PERFECT mating surfaces, and doesn't add anything towards safety. I'm running a factory 968 gasket and will continue to do so. I've blown an o-ringed widefire, cometic, stock, etc. over the years. The current motor has supported many dyno pulls at 23psi. Tuning is all that's relevant.

Thom

Agreed. I can think of several other high end builds that had problems with the MLS headgasket but none with the stock one, running the same amount of boost.
I would think the MLS will be even worse than the stock HG on a 2.5 block where cylinders are not siamesed - happened to 2 friends of mine, cylinders vibrate so hard under high load that they end up cutting the HG.

I run a factory 968 turbo HG on the 3L but the additional costs are IMO not worth it over a standard 944 S2/968 headgasket.

MLS gaskets certainly work great on closed deck steel blocks, but I can only see problems happening on open deck aluminium engines where aluminium expands more than steel.

Paulyy

Even Patrick is having issues with his MLS on a closed deck block

Thom

I didn't dare mentioning it but there you go...

Paulyy

It's Patrick, Hell find a way to solve it!

reno808

i am not having any issues with my MLS. Special Tool also ran an MLS with no issues at all. There are many factors to get it right. Stocks leaves more room for error.

333pg333

Block/head flex. Don't think it's detonation. We run pretty low ign numbers and E85. Even with deck plate, massive headstuds etc...we still stuffed our last Cometic...but we were able to keep the car on the track for most of the day. Couldn't do that with a stock one. Who knows which one might leak first though? I tend to think better the devil I know now re the Cometics. We have another process that we're going to do on the next motor which should help even more...but for the threadstarter I'd say go for stock.

lart951

I used mls with success for 4 years 21-23 psi no reported issues, I used Danno's system

Chris White

Many ways to skin a cat....but why would somebody want to skin a cat?

Generally -
MLS with after market head studs (less stretch)
Stock with stock head studs.
Wide fire with Oring is a good 'old school' fix. it allows for a little movement before it fails.

Head gasket factoids
Detonation will make any headgasket fail
No headgasket will cures head lift
Lots of flex and movement will cause fretting corrosion (I am guessing this is what Patrick is dealing with)
A well tuned 944 could probably run on a tissue paper headgasket.
A badly tuned 944 won't last regardless of headgasket type.

URG8RB8

As usual, well said Chris!

lart951

Did you ever shared this with special fool?

Chris White

I tried but I don't think he heard me over the gushing water noise in the background!