EvilRed98

Hey guys, I read the sticky, and am still not getting the answeres I need. I have a 6.0L longblock with the stock alum heads.(317 casting) the stock C/R says it is 10.1 to 1. the stock Ls1 is also 10.1 to 1. However the cumbustion chamber volume of stock ls1 head is 66.67cc's and the stock volume of the (317) heads is 71.06. If I put the LS1 heads on the Lq4 block, what kind of C/R will I have ?? with the reusable metal gaskets, or the graphite gaskets. (not sure what I will use yet)

I have read that stock lq4 alum heads on an ls1 will REDUCE C/R, so what is the advantage of using the (317) casting number heads??

Any help will be greatly appreciated

blacktransam

iTrader: (13)

not sure on the compression ratio but the advantage of the 317's is lower compression for a forced induction set up

C5kid

iTrader: (12)

because the lq4 block is 6.0 (364 ci) a 5.7 (346 ci) the bigger combustion chamber is to keep the CR down in a 6.0 block.

Thus if you put 317 head on a 5.7 engine it lowers the compression to like 9.5-1 and if you where to put the 5.7 heads on the 6.0 it would raise the compression to 10.5-1

The 317 is great casue the flow jsut bout the same as LS6 heads but have lower compression, something you want if your goin w/ a blower setup....

C5kid

iTrader: (12)

oh yeah the metal gasket I am not sure what the thickness is but i just did the math on that combination of the 5.7 head on 6.0 block and its 10.44-1 so i was close saying that it would be 10.5-1

the lq4 specs are 4.00borex3.622stroke

BLK02WS6

iTrader: (2)

I am running LS6 heads on my 6.0L - they have been shaved .014 and my pistons have 2cc valve relief and I'm running GM 6.0L head gaskets - that calculated to 10.8:1 according to the engine builder. Don't know if that helps you, but thought I'd throw out a data point.

jrp

iTrader: (16)

the lq4 has a 9.4 CR stock, the lq9 has 10.1 CR. which 6.0l motor do you have, my guess is the lq4 as the lq9's arent as readily available. the lq4 runs the same heads (317) as the lq9 but it has dished pistons approximately 6.5cc's.

ls1 heads on the lq4 = ~ 10.0 CR
ls1 heads on the lq9 = ~ 10.7 CR

jrp

iTrader: (16)

wrong, GM didnt change the chamber size for the 6.0 engines, they used different pistons. dished for the lq4 and flat top for the lq9.

EvilRed98

I was told the engine is out of a 2003 escallade, and is the "high output" motor. Iron block with alum heads. I would rather not pull the 317's off the engine, if I am going to use them, but I want to use my stock LS1 heads off of a 98 LS1. It has the perimiter valve cover bolts, and individual coil mounts. The 6.0L is rated at 10 to 1 and so is the LS1. the cubustion chamber is only 5cc's smaller on the LS1 heads, which will raise compression on the 6.0L block......but to what?

jrp

iTrader: (16)

umm dude, go read my post, i already gave you the answer.

EvilRed98

oops, sorry man-----it's a good thing there aren't rules about being a dumb ***, cuz I would win the prize......thanks again