Iron ls2 vs LS6

**redbird555** · 11-05-2010, 07:38 AM

Ok guys I'm going to e doing a stockish rebuild on my ls1 soon. I have an 02 z06 cam and a set of 243 heads that I was planning on throwing onto my ls1 with a fresh rebuild just to keep all my driveability that and my budget wont allow a stall right now to support a larger cam. So here comes the kicker do I spend a grand in buying a rebuild kit and do the ls6 conversion myself or do I sell the ls1 and get a low mileage lq9 and use the z06 cam and heads to make a slightly hotter version of an ls2? I cant seem to find a dyno of an ls2 vs an ls6 to compare but I'm told the ls2 will make much more torque down low and under the curve thus making it the better engine. My only concern is will the 80 extra lbs of weight take any advantage of torque the ls2 style engine has away? Basically I'm wondering whats going to give me the most useful power and torque and get me down the 1320 the quickest?

**Firebirdjones** · 11-05-2010, 06:06 PM

Talk to Casey (BAD EFX), he's done the LQ9 swap using an LS6 cam and heads. From what I understand it runs pretty decent.

I personally would vote for the larger cubed motor, especially with the auto and no stall converter. I like torque more than HP, and that's exactly what you'll need to get the car moving without a converter, and you can do it with less gear.

Finding one with low miles (under 50K) isn't the easiest. I was searching for an LQ4/LQ9 for a 72 Blazer swap, seemed the local places were a bit scarce around here.

**TLS_Addict** · 11-06-2010, 07:10 AM

Doesnt the LS2 basically use the 01 Z06 cam? Something like a .525 lift? The other specs might be a little different but as you know the 02 Z cam is around .550ish correct?

I would say go with bigger cubes, the 02 cam, and the LS6 heads.

BUt doesnt the Ls2 have the 243 heads just without the sodium filled valves?

Not sure but like said, no replacement for displacement.

**Firebirdjones** · 11-06-2010, 08:03 AM

Originally Posted by TLS_Addict

Doesnt the LS2 basically use the 01 Z06 cam? Something like a .525 lift? The other specs might be a little different but as you know the 02 Z cam is around .550ish correct?

I would say go with bigger cubes, the 02 cam, and the LS6 heads.

BUt doesnt the Ls2 have the 243 heads just without the sodium filled valves?

Not sure but like said, no replacement for displacement.

You are probably right on all counts. I'm thinking that when most people mention the Z06 cam they are talking of the later version (405 vs 385 hp)
That's the way I took it anyway. You are right on the lift of the second design Z06 cam (207/218 and .551 lift on a 117 lsa)

I know the heads on the LQ motors do have the same port configurations as the LS6 heads but they carry a different casting number and they also have a larger combustion chamber to knock the compression down, especially the earlier LQ4 versions.

**TLS_Addict** · 11-06-2010, 08:35 AM

Originally Posted by Firebirdjones

You are probably right on all counts. I'm thinking that when most people mention the Z06 cam they are talking of the later version (405 vs 385 hp)
That's the way I took it anyway. You are right on the lift of the second design Z06 cam (207/218 and .551 lift on a 117 lsa)

I know the heads on the LQ motors do have the same port configurations as the LS6 heads but they carry a different casting number and they also have a larger combustion chamber to knock the compression down, especially the earlier LQ4 versions.

Yeah, I think the LQs are used for boost engines. Maybe wrong but who knows.....lol

I think the OP should go with the larger engine.

**Firebirdjones** · 11-06-2010, 10:14 AM

Originally Posted by TLS_Addict

Yeah, I think the LQs are used for boost engines. Maybe wrong but who knows.....lol

I think the OP should go with the larger engine.

You are right, the lower compression heads from the LQ engines made them popular for boost applications.
Simply swapping on some real 243's with a tighter combustion chamber would make it close to 11:1. Remember LS6's were 10.5 but we are dealing with a larger bore here, which also affects the compression.

I agree, I think it would make a great motor to swap in, and relatively cheap to do. Low and midrange torque would be a ball to drive in front of an automatic tranny, and not much rear gear needed either.