A friend of a friend is building up an LS1 and is contemplating using PN88958765 "CNC-Ported LS2 Cylinder Head Assembly" from GMPP. Will the stock LS1 intake work well with this head? What would be better? TIA: I know a lot more about Gen I, Gen II, and Mk. IV's than about Gen III/IV and I am relying on you guys!

Rich

 

Rich - Basically the GM performance ported LS2 cylinder head is the same thing as the ported LS6 head, it has the same casting number (243) except this is clearanced for a 4.00" bore and does not have the same light weight sodium filled valves the LS6 does. It will work with the stock LS1 intake, but if he could get his hands on an LS6 intake off of a 2001-2002 F-body or 2001-2004 Corvette he would be better off. A FAST 90 would be even better, but depending on how radical his setup is it may not be worth it. What type of combo is he putting together?

 

It's a blower setup with 10-12psi of boost. The goal is 600rwhp.

Rich

 

P1SC? D1SC? I think the LS6 intake would be fine in that case, as the outlet on the blower is actually the same size as the opening on an LS6 intake. Another cheap option to go with would be the LS2 intake, stock for stock the LS6 intake actually flows better even though it has a 78mm TB opening as opposed to the LS2's 90MM opening, but with light porting the LS2 manifold seems to be pretty popular with the C5 FI guys. I would not recommend a FAST manifold for that application.

 

D1SC. Thanks for the advice. He already has an LS2 intake, if memory serves. So maybe go with that?

Rich

 

Yes, the LS2 intake would be fine. Search around on Corvette Forum, there was a post about cleaning up the ports to improve flow. I'll see if I can find it. Alot of guys run those on larger cube FI motors.

 

LS2 intake is fine for the reasons Mike just said.

I made 514rwhp through the auto (unlocked) with the stock bottom end 346, little P1SC, LS6 intake manifold, 212/218 cam, and Stage 1 853 casting Lingenfelter heads.

600rwhp will be a CAKEWALK with that bigger blower and those "stock" castings.

Is he building a motor? What volume pistons will he use to combat the small combustion chambers of those heads?

Mike

 

We haven't thought about pistons yet. Did yours last with stock pistons? How much boost were you running?

Thanks!

Rich

 

Mine lasted with the stock pistons for the short time I had it, but there's no way in hell I'd trust it over an extended period of time. I was running the stock P1SC pulley with the twin mini intercooler setup that comes with the P1SC for the Corvette.

If you're going with the stock pistons, you definetly wouldn't want to use those heads... You'll end up around 10.5:1.

If you want to use the stock pistons (which there's really no reason to unless you ran out of money ) then you'd probably want to try the 6.0L heads off of the LQ4 and LQ9 truck motors, which have 72cc combustion chambers and will drop the stock compression down to a much more boost-friendly 9.5:1.

Mike

 

Only the LQ9 came with the 317 heads, the LQ4 heads were different. There was a SWEET post on the 317 heads that someone recently deleted. Too bad, it was funny. The 317 is an LS6 port design with the 72 cc chambers as turd already posted. You would be far safer using those heads on a stock bottom end, but there are a few things (primarily rod bolts) I would look at changing if I were to go that route. You can pick up a good budget shortblock with forged rods, pistons, and ARP hardware for right around $3000, if you want it to last that would be the way to go.

 

Why are you infiltrating my forum? Shouldn't you be wasting your time on oldvetteforum or lsjuantech?

 

Eh, I hate LS1tech. There's 43 posts on the first page about "What cam is best for MY setup" and they're all @ssholes with different catbacks and think therefore because they have the Borla system as opposed to a Hooker system that they need a different cam, or somehow THEIR car is different than the 58 million other people who make "What cam is best for MY setup" threads. I'm tired of reading questions on CF like "If I use Zaino as opposed to Meguiars, will my car be faster?" or "Does anyone know where I can find these tail light louvers in brushed aluminum?" "Does the performance hood seal really gain 5 hp?" My favorite ones are where people do stupid **** like this:


Yes, that is Z06 mesh in the AC duct that goes between the dash and the door.

 

Wow. I mean.... it's gotta match, right?

 

I was under the impression that the 4.0" bore LS2 heads could not be used on the smaller bore LS1. Am I wrong or right???

Re'

 

They will work just fine. It is the larger 4.065" LS3 / L92 bore heads that will not fit.