i'm doing a stock lq4 short block with some L92 heads that i'm going to port my self..

i would like to get comp up to like 10.5-1 or 11-1 on the engine vs is i just bolt the heads on and run a .006 smaller gasket i will be only 9.77-1

so for me to get that i would have to run a .006 smaller gasket and the chambers would have to be 62cc or 58cc.

the cam i'm doing is 246/253 630/630 with either a 110 or 112 lobe

would i smack a valve into my pistons with this setup..the L92s are a 15 degree head also right..if i roll the head to 12 degrees i know it would help me out some.


thanks for the help

 

I would think someone that buids 1000 hp 355 ci small blocks would know...

 

well consideing i dont have a short block here right now to know how much the piston is down bore or the heads..its sort of hard to tell if they would or wouldn't jack ***.if i had all teh parts here i would already know..figured it was easier to ask vs getting all the **** together then checking and going well damn that aint going to work.

 

No matter what you are told here, if you don't check you are begging for disaster, and yes that cam should smack the ever living **** out of the pistons....

 

I have the LS2 and a set milled .025 for near 11:1. It is too close with a 228 xer cam. You need to flycut. Idont know anything about the Lq4 but if it has flat pistons and comes out of the hole the same distance it wont work. Flycut and you will be fine. Is the Lq4 a 4" bore?

 

yes the lq4 is a 4.00 bore and is 9.5-1 comp with a 71cc head.

i figured i would smack the valve but again i dont have the stuff so cant check.i will probley just run the 9.77-1 comp..it should make 500rwhp

 

The lq4 is basically an iron block equivalant of the ls2 with different heads.

 

Suicidal,

If you can I would get your pistons and cut reliefs and then you can probably do what you want and even mill them a lil more and get your compression to where you want.

 

i'm pulling the pistons out to replace the rings so i can fly cut them.

also i just read that the lq4 pistons are not the ones above deck some but are at zero deck with a 6.7cc dish

what is the max u guys think i could run for comp?

 

I don't have an indicator to measure the amount, but it certainly feels like the pistons are slightly above the deck on my LQ4. The pistons do have a dish.

 

i'm a somewhat newbie to building engines that actually make power. so i have a question

they say cam selection determines ptv clearence so how to i know if i have too big of a cam and how much i can mill the heads? i'm so confused but want a c/r that can run 94 octane

 

LQ4 pistons are not zero deck, they are just like the other LS based pistons. They are dished 6.7cc's. Mine are out .010.