lq4 questions

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Jan 18, 2013 | 05:09 PM

Gluemaker

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From: Aiken, SC

lq4 questions

Ok, my ls1 gave up. I picked up a rebuildable lq4. It's at the machine shop right getting the usual. When It comes back I'm going to assemble it, throw in a cam and appropriate supporting mods. My questions are regarding compression ratio and power. I know that the lq4 has a lower compression ration than an lq9. Should I change out the pistons for lq9 or aftermarket? Leave the factory pistons and mill the factory heads? Goals are solid 4xx whp via a 6spd and a cam with ls6 intake and full exhaust.

Jan 18, 2013 | 06:20 PM

Redbull87

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what heads are you going to be using?

Jan 18, 2013 | 06:23 PM

garygnu

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mill the heads,alot cheaper then new pistons.

Jan 18, 2013 | 06:30 PM

Gluemaker

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From: Aiken, SC

Well, I was thinking the stock 317's but if I can run a deal on 243's, I'll run those. Right now I havent made head plans as I want to be efficient and keep the budget down.

I'll say this, I'm open to ideas and opinions. I don't want to pick my valvetrain without knowing the where its headed as a combo. If people are milling 317's and running a certain cam with an ls6 intake, I'll look into it. If other heads are the way to go I'll do that. What I don't want is for my 6.0 with a cam to make the same power as my ls1 would make with heads and cam. If it's going to head that way because of compression then I'll just stick with getting my 5.7 rebuilt.

Last edited by Gluemaker; Jan 18, 2013 at 06:45 PM.

Jan 18, 2013 | 11:11 PM

Redbull87

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better start looking at some 243's and mill them to bring up the compression on a budget

Jan 18, 2013 | 11:52 PM

Gluemaker

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From: Aiken, SC

I wouldn't mind doing that. I need more definitive answers.

Jan 19, 2013 | 08:27 AM

KCS

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From: Conroe, TX

Since engine is apart anyways, swap to some LQ9/LS2 pistons. They're a lot cheaper than 243's and its much more difficult and costly to offset the 8cc dish with milling/etc.