LQ4/LS3 build
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From: Little River SC
LQ4/LS3 build Wanted to throw this out here and get some opinions. Have a std bore LQ4 block and 24x crank. Can get a set of unused LS3 pistons taken out of a crate motor for next to nothing. Was thinking of getting some aftermarket (lower end) rods and putting a shortblock together. Have a set of 821 heads and LS3 intake to go on it. Motor will never be boosted and will have a cam in the 230ish range. Anybody see any problems here? what about using later, floating factory rods and getting them redone?
Just my .02, but why not get a set of gen 4 6.0 rods and pistons rather than doing all that work to get the LS3 pistons to fit? You can probably find a set of floating LQ9/LQ4/LY6 rods and pistons for $150 or so. Not sure if the cost to bore would be worth the HP you'd get out of it. 
There's always the aftermarket Hypereutectic flat top pistons for 6.0's that come in .020, .030, have coated skirts small rings for $200-300, good for budget build. Lots of cheap ARP equipped 7/16" i-beam rods out there in 6.098 or 6.125" length, they're better than stock iMO because they're doweled, not fractured.
Wanted to throw this out here and get some opinions. Have a std bore LQ4 block and 24x crank. Can get a set of unused LS3 pistons taken out of a crate motor for next to nothing. Was thinking of getting some aftermarket (lower end) rods and putting a shortblock together. Have a set of 821 heads and LS3 intake to go on it. Motor will never be boosted and will have a cam in the 230ish range. Anybody see any problems here? what about using later, floating factory rods and getting them redone?
The clutch was slipping really badly, so it only went up to about 5k RPM, but it still made 413whp with 241 heads, LS1 intake, and a 230's duration Comp cam. It now has 799 heads, different 1-3/4" headers, and a SPEC clutch so I should have real number in the coming months.
I'm doing another one now with a block that had a piston come apart. The damaged cylinder cleaned up at 4.050", and I found a set of 4.060" forged pistons in the Classifieds that I'll be using.
Fair enough. I agree on the balancing. I'd do that regardless. Even if it's just a stock untouched short block. Good luck with whatever your decide.
I did the same thing to the engine that's in my Trans Am, but I have cathedral port heads on there. I used GM floating pin LS3 rods and pistons with a stock 24x crank. I also used Hastings rings and ACL bearings.
The clutch was slipping really badly, so it only went up to about 5k RPM, but it still made 413whp with 241 heads, LS1 intake, and a 230's duration Comp cam. It now has 799 heads, different 1-3/4" headers, and a SPEC clutch so I should have real number in the coming months.
I'm doing another one now with a block that had a piston come apart. The damaged cylinder cleaned up at 4.050", and I found a set of 4.060" forged pistons in the Classifieds that I'll be using.
The clutch was slipping really badly, so it only went up to about 5k RPM, but it still made 413whp with 241 heads, LS1 intake, and a 230's duration Comp cam. It now has 799 heads, different 1-3/4" headers, and a SPEC clutch so I should have real number in the coming months.
I'm doing another one now with a block that had a piston come apart. The damaged cylinder cleaned up at 4.050", and I found a set of 4.060" forged pistons in the Classifieds that I'll be using.
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Never bothered to check. On the first engine, since I just wanted to use stock rods and pistons, I didn't think it would really matter since I wouldn't be putting much power to it. I figure the pistons would probably go before the cylinder walls would be an issue. I just recently had the heads off so I had a chance to inspect the cylinder walls; everything looked normal. Nothing weird that may indicate an issue.
There was a guy who had built a 435ci LS for EMC (4.065" bore x 4.185" stroke) and he had said when they mic'd the cylinders, there was plenty of meat for an NA application. I think he made nearly 700hp at the flywheel. I think his name is Roycroft.
There was a guy who had built a 435ci LS for EMC (4.065" bore x 4.185" stroke) and he had said when they mic'd the cylinders, there was plenty of meat for an NA application. I think he made nearly 700hp at the flywheel. I think his name is Roycroft.
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