1320

iTrader: (6)

I could just leave it at that, and Im sure many would say never....until the first turbo buick guy comes in.....lol

Im an oldtime turbo buick guy and stacking head gaskets is common, even three on each side, so I was wondering if anyone has done it on an ls block to lower compression?

Tuning seems to be a lot more tolerant of the lower compression engines. All the 8.5-9.25 engines I do take a lot more boost and timing then a stock compression engine before knock. Ie, a boost 5.3 with 317 heads makes more power then a stock lq9.....both front mounts, both meth, both similar turbos.....the 5.3 will take way over 10(I dont even know how much) where as the lq9 is on the edge at 9-11 psi on 91octane.

Anyways.....stacking? Im think Im gonna do it to a lq4 with an s400-75.

smokinHawk

iTrader: (48)

i would think it would defiantly leak!
why not just use a thicker cometic head gasket, they come in all types of thickness.
but then you have the quench debate lol./

98Z28CobraKiller

iTrader: (17)

I'm guessing you dont mean MLS gaskets, right? I can't see the MLS gaskets sealing if they are stacked.

cellulis44

iTrader: (11)

I wouldnt try it with a LS

sujomatt

iTrader: (7)

try it, if it works - cool, if not.. ur labor

stevieturbo

Why bother with **** like that ? Why not just do it right ?

Although as a MLS gasket is made up from layers anyway, I guess to a point, there is no reason why adding a few more layers would do much harm.

But when pistons and heads etc are available so cheaply, just do it right.

NemeSS

iTrader: (127)

sounds like a leaking band aid at best
many have gone single digits and 1000+bhp with a conventional mls gasket

1320

iTrader: (6)

On a stock lq4?

I dont see the leaking as a problem, really. Pistons and rods are the right way, but some people dont have the budget. (This isnt my own car)

The owner is on a strict budget. And lowering compression, would do two things....cost only about $140 total, and make the otherwise stock lq4 get down to around 8.75 to 1 which should (all things being equal) lead to a longer service life under boost, esspecially if the owner(in this case is green) new to turbos. Lower compression makes the mistakes a tad smaller when they happen.

And why hasnt anyone referenced the routine stacking that turbo buicks do, with virtually identical 4 bolt per cylinder head bolts.

BTW, this is a 1800lb sand rail with a glide and 8.8 irs.

NemeSS

iTrader: (127)

not on stock lq4, but i meant with other setups.
seems like the owner should take it easy on the psi, if hes a green to turbo acceleration, im sure 10psi is more than enuff.

sounds like u got a project/writeup brewing

SKINNY69

$140 is a nice investment towards forged pistons. Tell the guy to save for another month and do it right. Boost and bandaids don't mix.

1320

iTrader: (6)

Thats true, but its only 70$ compared to new pistons as it would still need two new head gaskets. Then you dont get really do just pistons....

pistons/ rings = $600
rods = 300
balancing......200
plus more.... undoubtedly.

plus assembly....

besides, of the many turbo lsx engines I ve done, I still have yet to hurt a piston. I ve never hurt a bearing even but I see plenty .....form stock to boosted.

TURBO6.0L

iTrader: (1)

With boost you are asking for trouble. I have heard of people stacking copper gaskets but never MLS or Cometic's. Since it is on a sand rail it should be easier to pull it apart if it starts leaking. Let us know how it works out.

sujomatt

iTrader: (7)

1320, keep us posted if you do in fact make that change - interested in seeing how things work out

HUNTER02SS

iTrader: (24)

I don't think the 75ft lbs. of torque on the head studs are going to be enough to keep them from leaking. I am sure the buick guy's that do this torque there studs ALOT higher than that! On the other hand, Can the guy afford the head stud's?? Studs are a few hundred themselves.