sujomatt

iTrader: (7)

just a note, i have GM MLS gaskets on my car.. have ran between 10 and 14 psi and never had a problem

stevieturbo

And many many people have used them at much higher boost levels, and very high power with no problems either.

Some people just want to blame other stuff, for their own failures.

FastKat

iTrader: (10)

What compression ratio were you running at 15psi? Was it the stock ~10.5:1 or were you running a dished piston or larger chamber?

Could cylinder pressure be the source of your failure at 15psi, or is it a different factor?

What kind of failure did you have? Could it have been a bad tune or a defective block? (not a block with an inherent design defect/limitation)

BigRich954RR

iTrader: (1)

IF you have the money go Warhawk has alot of plus over the ls2 block.

jobberone

I'm running a low compression ratio with custom turbo pistons. I believe the gasket failed as three of four cylinders on that side where 'cleaned' by steam. There was no damage to the pistons or rings but one cylinder sleeve failed then eventually the block failed. The gaskets used were ordinary GM MLS gaskets. A Cometic gasket could have failed, too, but I'd have never put plain MLS gaskets on the car. Too much boost even at the 10-15 the car saw.

The leak went on for some time just wasn't noticeable to me until it started breaking down on the very top. We thought it was plugs and wires. The fuel started fluxuating at the top (of WOT). Then it let go. Pulled the head and busted sleeve and block.

Many years ago I raced Porsches when turbos were coming in again to racing and production cars (80s). We ran thru a lot of cracked rings and pistons in those days despite the leaded gas with very high octane numbers. Just a boost gauge wasn't much help. Point being with so much power it's hard to tell when you're losing a little power until its obviously something wrong or track times tell you something's up. You'd take the engine down and couldn't believe what you'd find and the car still running fairly strong.

jobberone

You can get away with a lot until it fails and nothing lasts forever. People run stock internals yada. But I'd never put stock gaskets on my application by choice. Chevy is using some Cometic gaskets like the LS7 one so just because its stock doesn't mean it won't work.

Sooner or later if you're boosting enough something is going to let go. If you have a LS1 then at near two bar you're going to eventually lift your heads. Probably.

FastKat

iTrader: (10)

So you blew a hole in the sleve... or it cracked? or scored? or moved in the block? When the block failed, was that related to the failed sleve, or was it a bearing? did the head studs pull the threads out of the aluminum block? How did the block fail?

Any pics? I always love to see FI carnage!

It sounds to me like you have an outlier... maybe you got a bad block or had some other issue. The overwhelming majority of people that take the aluminum block to and past your power level have no issues with the block itself, provided no other extraneous issues.

Jimmy P

iTrader: (177)

My L19 studs are currently torqued to 115lbs on my LS2 block . Only reason I had to go that high is because I learned that the bolts need to stretch to actualy do their job. If I had the regular ARP studs I would of only went to 95lbs.

Nimitz87

iTrader: (17)

listen to Shawn @ VA speed...he knows wtf hes talking about and if you don't think so just look at the motors that are being put together at his shop, Phil's LSX powered mustang w/ a single is a testament to that, as well as Brian's car...ls2 block holding big power on 4 bolt heads.

you just have your head so far shoved up your *** that you think all the advice you have already been given is gospel...then why ask the questions if you have it all figured out?

Chad

stevieturbo

That saved me saying it lol