fastrt

iTrader: (48)

I have a lq4 and have been thinking about building a high comp lq9 with 243 heads and ls2 pistons and rods, arp bolts and 11to1 cr ruffly. my question is, what do you lq9 guys spin you motors up to? 6500-7000? I know the weights of the pistons and rods are more than a lq4. lq9 and ls2 pistons and rods are supposed to be the same so I have read, and I know gto/vettes shift around 6500/7000. also what would be the best rings and bearings to go with and why?
thanks

dkota1968

iTrader: (1)

Ive read that lq9 and ls2 pistons are the same but for some reason i think the newer style ls2 rods where stronger for some reason(someone chime in if im wrong). I think if you are gona build anything with some power use some budget forged pistons and rods. I bought a ls2 longblock that had 2 rods break and broken pistons and what was a basically stock engine, so i wasnt really impressed. I planed on rebuilding it anyway and for the price i paid the heads and valvetrain where worth it. If you did a stock rebuild like your describing its basically a LQ9. Akerly and childs rings seem to be popular rings that are used. Good luck

BigTex

iTrader: (16)

I believe the rods on the LS2 and LQ9 are the same too, as well as on the newer LQ4s. Cranks however are different, with the car motors having gun drilled main journals.

On my LQ9, I would shift it 6300-6400. On my LS2, I try not to go past 6500.

skyhighsami

iTrader: (8)

I am using an iron LQ4 block and LS2 rods (same as LQ9) and either LS2 pistons or LQ4. I bought both, the motor will have some Dart 225 head which has a 62 chamber so I think with the LQ4 pistons it would be like 10.6 and the LS2 would be like 11.2 or something. I am leaning towards the LS2 with a Cometic head gasket because some of the are a little thicker. Anyway, I was planning to shift around 6400 but one thing not mentioned if this is going in a truck the truck intake at 6000 falls on it's face. Just a reminder if you haven't thought about it or didn't know

skyhighsami

iTrader: (8)

Also at those RPMs I would atleast have some ARP rod bolts. Just something else to think about

BlackGMC

iTrader: (31)

so whats the difference between the ls2 and lq4 pistons?

fastrt

iTrader: (48)

the ls2 and lq9 pistons are flat top's. the lq4 are dished.
I am planning on a fast 90, or the new edlebrock intake, and depending on cam, shift around 6500. I shift my 5.3 at 6600, and see 6800 on burnouts. what about rings? total seal? stock? and bearings?