smokinHawk

iTrader: (48)

I thought id share to every one what i have found out about these heads as im putting them on my T-76 turbo transAm to drop compression and flow better. Alot of this info came from other post and talking to Valvegod.

00-cast iron dont bother messing with them

01-02 aluminum
They have exhaust ports similair to the ls6 heads.
the chambers are 69cc, yes 69cc, I had mine cc, and valvegod stated this also he also had them cc'ed. stock is 67cc for ls1, 65cc for ls6. the valves are the same as the 5.7 (ls1, ls6) heads 2.00 intake, 1.55 exhaust.

compression
find out what it will be
http://www.rosspistons.com/CR%20Calculator.htm
3.898 bore (stock)
3.62 stroke (stock)
.052" head gasket (stock)

68cc equals 10.05:1 CR
69cc equals 9.94:1 CR
thats using the stock head gasket

now ok i want my compression lower then that since illl be boosting, i wanted it down to low 9:1's
im gonna take out a few cc's so ill be at 72cc (having them ported and polished to by a local porter: $400)
that would get me to about 9.5:1, still aways to go
so im gonna use a thicker MLS gasket from cometic
1800-752-9850
1440-354-0777 (tech)
they have different thicknesses
.125
.098
.078
.067
.057
.054

im going with the .078" this will give me a CP of 9.11:1

for studs im going with ARP studs and 12 point nuts (190,000 tinsile streath).
Katech curently sells these the cheapest at about $205
1586-791-4120

To get some 6.0L heads the easiest way is to give Shaun, (valvegod) a call at 1-248-276-0483, these are used heads, fully assembled, currently about $450 a pair.

I'll find how much boost ill be able to run on these heads after i lower the compression. I was only able to see about 6psi on my old set up (but kept it at 5psi)( sall knock at 7psi)

this is all i know right now any one care to add there findings, maybe we can put this in the FAQ section.

GeorgeC

Is this on a stock shortblock? If you're building a new shortblock, just stick in a slightly dished piston to drop the compression where you want it to be...

Us NA guys can do just the opposite and use a domed piston...

JimmyKash

you dont want a gasket that thick, you'll be detonating a lot because the quench is going to be sooooo large

read up on quench and you'll understand

smokinHawk

iTrader: (48)

Yes ive read up on all of that, this is the cheap fix, granted its not as good as getting dished pistions, but for those who need to drop the compression cheaply. Im already broke with purchasing the turbo kit, now a gasket goes so im in trouble. Im not just gonna put everything back on the way it was and wait for this to happen again.
The lt1 guys have been using thicker gaskets for quite awhile.
this is just info about 6.0 heads.

SJH

hmmm, I would try and keep your quench tight if possible.
I dropped my compression and at the same time using a thinner gasket tightened the quench.
I think this will work very well.

I have 2 sets of early 98 heads that cc'd just under 70cc stock. I measured, re-measured and again re-measured as I could not believe it.
But that's what I got. I removed just over 3cc on my heads as seen in my other post.

Steve

<small>[ June 14, 2002, 11:56 AM: Message edited by: SJH ]</small>

Mike at Boost Performance.co.uk

I agree, I won't suggest using the thicker gaskets as you will lose the benefit of the nice factory squish setting. If you drop compression via a thicker gasket you may be heading for detonation earlier and then something will have to give ( if the gasket won't give then it may be the pistons). If you keep the squish tight you won't detonate and the car will make more power both on and off boost. I view the gasket as a safety valve. You could make progress by milling the block and actually increasing compression slightly because the squish would be tighter. Good luck with it.

smokinHawk

iTrader: (48)

mellow yellow is ahead of me, hes running a thicker gasket also.

VINCE

iTrader: (1)

Keep me posted.. I am going to be doing the same thing.. I am glad you are a year ahead of me..