0EG@EnglandGreen

LQ9 72cc unmilled heads : anyone have a pair for sale?

Yes, yes, I know, I could post this in the Parts section but since these heads are almost exclusively used in FI, I thought I would ask you guys and gals first. :bb

Hoping to hit 9.0:1 STR with Cometic gaskets on a LS2. Piston cc and brand are unknown at this time - any suggestions? Needs to withstand 15+psi for long periods of time (road race) and not have to be changed every xxxx thousands of miles.

Any help would be appreciated. And go easy on me - I'm new to this LSx thingie

EG

TURBO VET

I have a set that are #317 castings for $350 shipped. They are used but in good shape. PM me if interested.

0EG@EnglandGreen

PM sent!

DOUG @ ECS

EG, I was thinking of going to the ETP's on my car, I have a well above average set on my vert now if your looking for something wild to put on there. (not as cheap as the the other set tho).

BLOWNZO6

Sent you a PM, I have a brand new set that are completely assembled.

I would take $550 for them shipped, that is what I have into them.

If anyone is interested.. let me know.

Nick

0EG@EnglandGreen

Doug, I am looking for something wild - you know the size of the godzilla cam I'm stuffing into the LS2 - I need all the airflow I can muster. I won't have to worry about charge stall with that puppy

I sent you a PM.

0EG@EnglandGreen

PM sent

0EG@EnglandGreen

Heads purchased! Thanks everyone

Love this Forum !

EG

0EG@EnglandGreen

Any suggestion on pistons? <see post #1 for criteria>

BLOWNZO6

Yes...

JE makes an off the shelf piston... part number 221178

It is a 4.060 bore, for a 4 inch stroke with a 6.125 rod. With the 317 heads and an off the shelf GM gasket that would put you at 8.9:1 with a 0 decked block.

Hope that helps!!!

EDIT: I emailed you the page from their catalog and the compression ratio calculations. These are the pistons I was going to use if I went to an LS2 block. Just cannot justify the extra jack when I can make up for it with the twist on the boost controller...

0EG@EnglandGreen

Thanks Nick. I'll be using a 4.100 inch stroker in my new LS2 for 412ci. Rods are still up in the air but probably Lunati Pro/Mod rods. Will the JE work with that long stroke or do I need to get shorter rods?

Stephen

BLOWNZO6

I am not sure what you are trying to accomplish by using a 4.1" Stroke? I don't think it matters either way.. but you are going to get 412 by using a 4" bore piston and a 4.1" stroke? Sounds like you are going to have to use custom pistons. I think you are going to have a hard time finding an aftermarket piston that is stock bore for that stroke. If you have not bought your crank yet.. you should consider that there are plenty of off the shelf pistons that will work with a 4 inch stroke. That piston I showed you coupled with a 4" stroke crank will get you 414 CID.

You should certainly source everything together with a set idea of what your goals are. You have to pick a piston based on the heads you are using (which you have now) and then pick a rod that is compatible with the piston and crank you are going to use.

I think I remember reading more than one place that FI motors respond better to bore than to stroke as well. The guys at ECS can tell you what to use...

0EG@EnglandGreen

I struggling with the math here (and I have my post grad degree in Math ) but how can a 4.000 inch stroke and a 4.000 inch bore equal 414 cubic inches? The numbers work out to 402ci.... or am I missing something?

BLOWNZO6

You are not struggling..

The piston I showed you is a 4.060 bore... back to the calculator.

Or better yet.. use this:
http://www.c5frc.com/calculators/Com...Calculator.htm
Quick and dirty.

0EG@EnglandGreen

Doh! Just stupid, I guess

0EG@EnglandGreen

I didn't realize you could bore the LS2 (or LS1/LS6) .060 inches over. I thought they had to be sleeved for anything over .005 inches?????

<work with me here, I'm new to this LSx stuff>

BLOWNZO6

Hmm... the JE book says for 6.0L... BUT it does not specify Iron block or Al.. so I assumed either would be OK. I could be wrong about that.. best to ask the guys at ECS or someone on here before buying anything. I know the LS1's are that way.. but I thought for some reason that the LS2's were ok to bore... I will see what I can find out.

Mopar Jimmy

WHat ever the answer to the issue(s) that BLOWN Z raises i do agree that you should stick with a 4.00 inch crank as those have proven to be the MOST RELIABLE and best performers with LSX motors. I had a 4.125 brand new CALLIES CRANK fail in a 427 iron block LSX motor i had with a 4.060 overbore and the the crank failed after only 4K miles on it as the crank welds and reluctor wheel broke on the piece of sh it 4.125 forged BRAND NEW CRANK!!!!

My engine builder (very reputable here) told me that the crank failed because the geometry of the motor was off b/c the 4.125 stroke was to much for the iron 4.060 overbore. They then immediatley recommend that i go to a 4 inch crank and that is what i did with 0 issues after that.

I would go with the safe and battled tested big cubed crank for proven reliability and performance that being the 4.00 crank. TRUST ME 10 more cid is not going to matter with the MEGA POWER your ECS NOVI Powered LS2 motor is going to be making!!!!!! THe power will be there regardless and I would really focus on longevity, durability and engine life, especially since this is going to be an everyday driver

BEST OF LUCK!!!!!!!

zeevette

I think I remember reading the maximum overbore on a LS2 is .030.

Mopar Jimmy

That sounds about route to me can anyone confirm this? If my memory serves me right this 4.030 overbore with a 4.00 crank makes 408 beatiful and REALIABLE CID!