i have a fresh lq4 bottom end had redone about a year ago still on the engine stand, my pain is to rob my heads and cam thats in my ls6 that im pulling out of my car heads are redone never ran the cam is 227/234 .614"/.576" 113+2 (btr stg 2 ls1-2) with about 10k on it heads are TSP PRC 2.5 243's only milled very little to clean up

this is for my 04 rcsb 4l80e swapped 3.42 gear, thinking about swapping the pistons out for GM lq9 flat top wondering about compression since its a daily. what would compression be? to high for 91-93 octane?

at this point its a couple hundred bucks and my labor is it a bad idea what do you all thing?

 

All the alphabet soup around here I forget a lot of ****

but the rods from 4 to 9 are different. 4s are press fit and 9s are floating. I don't think you can use off the shelf 9 pistons

you can get hypers in a flat top 4.00 for a press rod tho

compression will be 10.9 ish. You're building an iron LS2, nothing magical here except the rod issue

 

i didnt know the rods was different, thanks for the info

think i might just do this, any idea on what kind of power this can make true a 80e?

 

The later LQ4's (I think 04-07) had the GEN IV full floating rods. What does the date stamp say on the block, just below the front of bank two cylinder head?

 

pistons and rods are not the original set that came with the block and i know they are not the dimple newer rods so just my luck id need rods to lol

trying to figure out if swapping to flat tops is worth it HP/TQ wise

 

Just find a take out set of LQ9 or LS2 rods and pistons

 

Probably easier to just buy pistons for the press fits... and by the prices people ask for used trash be cheaper too. New flat tops from even summit can be had for around or under $200...You don't need the floating pin rods for some N/A build. You are probably 10.1 or 10.2:1 compression where you are now with the stock pistons. I would just do the heads and cam as is and leave the bottom end alone being its fresh.

 

it is fresh never had heads on it since i installed the rotating assembly, i think i see what i can find as for replacement pistons the rings i have on these lq4 should work right? they are new

 

Did you check to see if it has the newer rods? You would be at around 10.9:1, basically an Iron LS2.....I did this same setup recently, took an L96, swapped in some oem LQ9/LS2 pistons and added some 243 heads and the Summit Stage 1 High Lift truck cam and it runs great, torque is excellent right off idle

 

its not floating rods

so i been looking on line and seen on ls1tech that if you swap to the gen 4 rods you need to have the engine balance or get the gen 4 crank along with the pistons is that correct?