voodoochikin04

iTrader: (3)

Why am I under the impression that bolting ls3heads on an ls2 is a nogo? I thought there was an issue with bore sizes or something that would make it not a good idea.. idk, the old brain is fried anymore.

ls1247

iTrader: (2)

iirc, it's just the 5.7 that has bores too small for the ls3 heads.

Mercier

iTrader: (15)

LS3/L92/LSA/LS9 heads require a minimum 4" bore. That means LS2, LQ4, LQ9, etc. all work fine with square-port heads. The L76 is actually 4" bore 6.0 that came in some cars(maybe trucks too or was that the LY6?) factory with LS3 heads so it was known it would work dimensionally pretty early on.

It's been done a bunch of times and I'm building one now(LS2 with LS9s) right here in the V section.

Some say that the 4" bore shrouds the big LS3 intake(and it does somewhat) but the results are hard to ignore. People make mad power on a budget with these heads. Many approaching 500RWHP. Camming properly is a concern because the huge ports actually like a small-ish cam, especially with the smaller displacement.

You do have to change the intake also though. Bonus is that the LS3 intake is pretty fantastic in stock form. It makes the LS2 look like a toy.

FuzzyLog1c

iTrader: (4)

I'll check my notes, but it sounded like they thought the on-boost profile of the TVS2300 was harder on the motor than the MP112. I'm not sure why--I never dug into it. FI was so far away at the time, and I was brand new to cars and the community. So I didn't ask.

At the time, seeing several V1 motor failures was enough to set me on the path toward a forged bottom-end. As I continued to learn more about the overall costs of the different motor builds and the effects of hybrid-roots and twin-screw superchargers on the rest of the car--fuel system, drivetrain, transmission, cooling, intake, suspension, and tuning tolerances, I totally changed direction and started on my present "foundation first" build strategy. The motor and supercharger will be the last things I do.

Sssnake

I have done the above for over 3 years with no issues to date (except LSA heads). I am even pullied down to get to 7.5 lbs of boost (lots of flow through ported and polished heads with healthy cam). It doesn't mean something won't happen tomorrow but it has been a very good setup to date. I do know of a few others knowledgeable folks that have broken ring lands. Again in my mind it has a LOT to do with the tune. I have been tweaking for a LONG time.

ls1247

iTrader: (2)

This thread mentions interference between the LSA balancer and the V1 ABS module.

https://ls1tech.com/forums/cadillac-...rger-v1-2.html

From scoping ebay, it looks like the LSA belt is 2 ribs wider than the v1 belt and much larger in diameter.

OP, which balancer did you use?

I'm guessing that ATI makes a wider pulley with a smaller diameter that would fit around the v1 ABS module while accommodating the wider LSA belt...but how's the blower going to like that?

Also, it looks like you adapted a 3 bolt ls6 throttle body to the blower. I'll assume you went larger than stock with this so which one did you use and did you have any problems tuning the thing?

Mercier

iTrader: (15)

I have a truck kit that utilizes a 6-rib belt. Possibility.

ls1247

iTrader: (2)

I don't know that I'd want to stay with a 6 rib belt because if that was even just barely adequate, GM would have probably used it. There were some reports of the 6 rib slipping on a maggie so I could only imagine what it would do on this.

Relocating the ABS module looks like a pain in the *** I don't care to mess with...

Mercier

iTrader: (15)

While I don't disagree, word is at stock boost levels it is somewhere near adequate. I'm not selling it as a great solution; just pointing out that you have folks doing this. IMO, you may be looking at the Maggie comparison backwards. I think that the TVS blower in the LSA setup, being more efficient, should turn slower than the Maggie at the same or similar power level. By simple math I think that equates to larger pullies, more belt contact area, and less slippage by comparison.

Of course that's at stock blower speeds. That's only fun for the first 10 minutes right?

Agreed @ ABS module. All I need is for that mess to get unhappy and start acting up. Looks like a beast you don't want to poke.

ls1247

iTrader: (2)

Correct, the belt slippage only happened to the guys who were dong pulley swaps to overdrive their maggies so it would stand to reason that a 6 rib could possibly get it done on a stock setup but where's the fun in that.

So I'm going out on a limb here saying that the last real piece of this puzzle is pulley sizing...

Mercier

iTrader: (15)

GM claimed there to be 556HP worth of fun there. But I'm with you. A waste. Maybe it gets you by until you feel like futzing with the ABS.

Where'd the OP go? Perhaps someone should PM so they get an email notice?

transdam

iTrader: (2)

I used a oem crank pulley off a 09 v2 ctsv and belt. I only had to slightly bend one of the hard lines on the abs modulator . I have put 2k miles on it with no issues.

fre1102

I have an LS2 and I'm happy to make my car the guinea pig, but this is my first GM and I'm not familiar with the details.

Turning wrenches, fine. But LS2/3/whatever, I haven't been keeping up.

Can I just buy OEM LS3 heads then the blower off a Gen. 2 V and slap it on there?

Mercier

iTrader: (15)

Those and the proper front accessory drive components. Here's the expensive route:

https://www.summitracing.com/parts/nal-19243525

Of course a melange of your current stuff with V2 stuff(Or see Lance Draeger on Facebook for a whole used setup) can get you there a lot cheaper.

Then heat exchanger, make some lines, reservoir and coolant pump.

You can actually use LS3, L92, LY6, L76, LSA, LS9 heads. All square port. LSA surprisingly flows the least due to a wing in the intake port.

EDIT: ...and then get ready to upgrade everything behind the engine.

vroom_vroom

iTrader: (5)

That is the sole reason I have not done a lsa on this car. You must go after everything else fairly quickly

Mercier

iTrader: (15)

I'm fairly confident you would at least get it out of the driveway before that diff turns into pixie dust.

fre1102

That's kinda okay with me, actually--my diff has the same whine every other diff has (I assume), so a swap is going to happen eventually.

I assume the transmission is fine. I don't know about the driveshaft and I'd like to leave it, but whatever. That diff. is going to be the terror item. And it's going to be a problem eventually even on the OEM engine.

Honestly, a supercharger, a better rear end, and a decent infotainment system and I might not need to buy a new car for a long, long time. And shoot--my bar for 'decent' is pretty low with respect to the radio.

Thanks for the info!

raven154

iTrader: (14)

Unusually I've had more issues with my transmission than anything else. Bent input shaft, broken counter shaft, a few other little things. Then a broken inner CV joint. The diff is still going strong though lol