help on raising compression on lq9 6.0...
 

i just bought me a 04 lq9 out of a escalade, my plan is to do a custom grind cam thinking of going with a 236/242 .602"/.610" 112lsa with 7.35 pushrods, im wanting to lower my the cc from 72 to around 67cc enough to get me in the 11's on compression, which im guessing ill have to have around .40 milled off to do so, havn't really figured it up yet but you get the point, will i run into any problems with ptv clearance with this setup, i know my best route would be to buy some 243's but don't have the funds right now, so just looking for some input or some suggestions on how to raise the compression a full point with this size cam and not running into problems, thanks for all the help

chris

i think youll have to lower the CCs of the heads to around 62cc to get 11.1 or even a tad more if it were me id look into a set of TEA stage 2.5 ls6 heads for the money i hear over on tech there damn good. as far as PTV i would think with that much duration and milling the heads to at least 62cc i would def check the PTV.
thats a hella cam you wanta run hope you plan on at least a 3600 verter :burnout:

i didn't think it would be that much, i thought i had heard just putting 243's on the 6.0 would put it around 11.1, i might have misunderstood tho, yea i would like to buy some heads just don't have the money, ive already spent enough money lol, just trying to work with what i got, i wish someone would want to trade me some 243's for my 317 and some money....and yep ss3600 stall will be the one...

Call Richard @ WCCH and talk to him, he will put you into the right direction. :nod:

243's on a lq9 is the same setup as an ls2. compression would be 10.7ish.

nope, it's higher than an LS2. It's 11 or 11.1:1. LS2 is 10.9:1

what are the CCs on a stock set of 243s 64:confused:

yea im pretty sure i read over on ls1tech that if you put 243's on a lq9 it would bump the compression to around 11.1

i thought they were 67cc

317 heads (stock LQ9) == 72cc (these are essentially 243 heads with different valves and bigger chambers)
241 heads (stock LS1) == 67cc
243 heads (stock LS6) == 64cc

An LQ9 with 317 heads is 10.1:1
An LQ9 with 241 heads is 10.7:1
An LQ9 with 243 heads is 11.1:1