: Mod LS6 or swap LS3?



Ct$-V
08-07-13, 01:38 PM
Good afternoon gentlemen,

Just wanted to get some feedback from you guys about a project that I am considering. With a little over 100k on the engine and starting to track the car, I am considering buying a 60k mile LS6 and doing Katech Stage II before swapping or taking a new LS3 and swapping it. Do you guys have any feedback? It appears as though the LS3 with mild mods will approach the LS6 with H/C/I. I have spent weeks reading on here and Ls1tech on what y'all have done and am now deciding that I need counsel.

More specifically, I can buy the 60k LS6 for about $2k and I have a buyer already for mine for the same price. I have a tech-friend of mine who is willing to do the swap (LS6 or LS3) for virtually free. The T56 only has about 30k miles on it and the rear-end is a Gen IV. Both were replaced by dealership under extended warranty. My budget for this is about $10k. The car will be my DD and so little down time and dependability are important. Also, I have thought about ditching the V for a Z06 but my wife just smiles and points to our kids.

After about 20 years of enjoying cars and reading forums this is my first post! I welcome feedback and experience from you guys...especially if there is something glaringly obvious that I am overlooking.

Thanks in advance,
~C

lollygagger8
08-07-13, 02:14 PM
If someone will do it for free???

LS3 for sure. Then put a blower (Whipple/Edelbrock/whatever) on it down the road after you change out the rear end with a 9".

DMM
08-07-13, 03:03 PM
LS3 with a baby cam, 1 7/8" headers, and a tune for sure. The things to look out for are the knock sensor compatibility and the 04/05 LS6 PCM does not have enough resolution to effectively use he LS3/7 card type MAF. You can buy the conversion harness for the 90mm t-body or make your own if you're crafty.

LS3 would be a better DD and still leave you grinning from ear to ear every time you get in it.

PISNUOFF
08-07-13, 03:15 PM
You can build a forged stroker 416 LS3 with a $2000 clutch for a total of $10k.

crankedupforit
08-07-13, 03:19 PM
Track as in ??? My thoughts would be LS3 for 1/4 mile. LS6 for road course. Being as though you're interested in Katech I'm thinking you're into HPDE and road course events. The LS3 is hard to beat for power potential from what everyone has said but they have terrible reputations for oiling issues on the road course without a dry sump. My LS6 is reliable but needs some major mods to produce over 400rwhp. Stay away from big cams for the LS6 since valve train life is a concern on a car that sees lot's of track time.

RyRidesMotoX
08-07-13, 03:29 PM
You can build a forged stroker 416 LS3 with a $2000 clutch for a total of $10k.

This... Doesn't matter what track your on, 1/4 or road course, that would be a pretty good motor. The power curve would be amazing. I wouldn't swap an LS6 for another LS6, you wouldn't gain anything for all the work. Put in a bigger better motor and never look back IMHO

Ct$-V
08-07-13, 08:20 PM
@lolly-yes, I am going to do all the estate planning for him and in lieu he is going to trade the bulk of the swap for the work...except for maybe pulling the crank to swap the reluctor wheels. But as others have said, might as well swap the cam.

Anyone else had luck with the Lingenfelter module? I was reading on LS1tech about problems back in '11. Have they rectified the gremlins? Would love to avoid pulling the crank.

@cranked-Good call, I am starting to study up on the oil starvation because yes, I am looking at road courses. Road Atlanta will be my mainstay but I would like to start traveling. Seems like anything over 1.3g's is problematic. But some of the dry sump solutions (with installation) would be approaching half the cost of the LS3 crate engine. Insurance is well worth it but where do we draw the line?

crankedupforit
08-08-13, 12:13 PM
@cranked-Good call, I am starting to study up on the oil starvation because yes, I am looking at road courses. Road Atlanta will be my mainstay but I would like to start traveling. Seems like anything over 1.3g's is problematic. But some of the dry sump solutions (with installation) would be approaching half the cost of the LS3 crate engine. Insurance is well worth it but where do we draw the line?

The LS3 oil issues were so evident that the Corvette Gran Sport and the new Camaro Z28 which were directed LS3 applications for track use come with a dry sump system similar to the Z06. The Corvette forum is fraught with horror stories on the LS3 starving out and destructing. I still think it's a fantastic engine, but it does need the dry sump if you want to put it to work.

PISNUOFF
08-08-13, 01:28 PM
What is the route cause of the oiling issues? If it is oil starvation caused by the pan, you would be swapping your oil pan to the new motor anyhow. Only other issue I could see is drain back into the pan causing it to starve for oil.

crankedupforit
08-08-13, 04:09 PM
Only other issue I could see is drain back into the pan causing it to starve for oil.

I've heard opinions that that the head design causes more pooling and there is more windage up on the top of the motor. No one has ever come up with something factual as far as I know. Someone like Pratt & Miller or Katech has never weighed in on the subject. So you may be right. I still think that unless you're really thrashing the LS3 on a road course on some sticky tires, you won't have any issues. The Katech Motorsport 550 LS3 race engine is found everywhere racing Grand Am, DP, ALMS with great success but again a dry sump is always there.

PISNUOFF
08-09-13, 06:47 AM
Agreed. I never had any oiling issues with my LS3 with LS3 heads. I wish I had asked Pratt & Miller last weekend when I was talking with them at MidOhio.

yooper
08-10-13, 12:53 AM
Run the 100,000 mile LS6 thats in the car now. Spend your money on seat time and start looking for a wrecked C5 ZO6.

Minytrker
08-10-13, 01:36 AM
I vote for LS3, but Im probably partial since I have one in mine.

http://www.cadillacforums.com/forums/2004-2007-cadillac-cts-v-performance/337849-ls3-swap-cts-v.html

Ct$-V
08-10-13, 09:58 AM
Run the 100,000 mile LS6 thats in the car now. Spend your money on seat time and start looking for a wrecked C5 ZO6.

I hear that. The crossroads that I am at is that I'd like to start modding the engine...but I do not want to throw good money at an engine with over 100k that is going to start seeing more track time. The other piece here is that of my resources, I have more money than time (relatively speaking). Left up to me, I would be seeing more track days. But with two kids (one of which is a newborn) at home. My ability to break away is more limited. That said, this is what I was looking at, already has a cam. And don't flame me too much, but I was going to call LPE and see if they have rectified, or at least be able to explain away, the problems with the crank trigger module. If rectified, I'd do one of these: Thoughts?

http://www.jegs.com/p/Chevrolet-Performance/Chevrolet-Performance-LS3-62L-376ci-480HP-Engine/1127485/10002/-1

http://www.jegs.com/p/Chevrolet-Performance/Chevrolet-Performance-LS3-62L-376ci-525HP-Engine/1941625/10002/-1

I know its the classic Hot Cam and ASA argument...but if the LPE module precludes me from swapping cams or amending the crank, then I'd rather have GM put it together and avoid assembly error. Last thing guys, I was thinking about the Kooks 1-7/8" and B&B for either of these engines. Is the 1-7/8" overkill? Likely would ultimately amend the intake and TB down the road. Thanks for the feedback and dialogue thus far.

RyRidesMotoX
08-10-13, 12:08 PM
I really think that you can do just fine with a rebuild on the LS6 provided there at no issues with cracks in the butt... I mean block. If you're dead set on completely replacing a motor then do an LS3 swap over having to do nearly the same amount of work and spend the same money for another LS6. Have you looked into doing like a 7 liter iron LSX block? Or something of that nature? That really opens the doors up to some craziness there.

Go 1&7/8 headers... That's the one thing I regret about mine. They were the same price and I had a mental retard moment and went 1&3/4. Its not a HUGE deal between the 2 but I want to go forced induction and the 1&7/8 are clearly better. Some people say that for a NA motor the 1&7/8 are too much but they do allow you the most room to grow later.

Ct$-V
08-10-13, 12:19 PM
I vote for LS3, but Im probably partial since I have one in mine.

http://www.cadillacforums.com/forums/2004-2007-cadillac-cts-v-performance/337849-ls3-swap-cts-v.html

Miny, have you tracked the swap yet? What kind of g's-any oil pressure problems? Looks like 1.3g's for over a couple of seconds is the issue.

PISNUOFF
08-10-13, 03:17 PM
I will give you $1000 if you hold (or even get to without wrecking) 1.3 g's.

Ct$-V
08-10-13, 05:25 PM
I will give you $1000 if you hold (or even get to without wrecking) 1.3 g's.

Fair enough, definitely have not seen that much. At Road ATL last month I hit 1.18 on Michelin SS. I just figured 1.3 was attainable when I go to slicks.

liqidvenom
08-10-13, 10:22 PM
I will give you $1000 if you hold (or even get to without wrecking) 1.3 g's.does that hold for others as well

yooper
08-11-13, 03:30 PM
Fair enough, definitely have not seen that much. At Road ATL last month I hit 1.18 on Michelin SS. I just figured 1.3 was attainable when I go to slicks.

Sent you a pm.

I consistently pulled 1.27 at Autobahn Country Club in Joliet, IL. Hard on tires.

Minytrker
08-12-13, 01:27 AM
Miny, have you tracked the swap yet? What kind of g's-any oil pressure problems? Looks like 1.3g's for over a couple of seconds is the issue.

Wont ever see the track, its just a fun daily driver. Its a lot faster than my G8 which runs 12.9's. I only ran the G8 to see if it would break into the 12's. Its hard to go run my street cars at the track when I have a race car. Zero oil pressure issues but I know its never seen 1.3g's for seconds thats for sure.

PISNUOFF
08-12-13, 12:39 PM
Fair enough, definitely have not seen that much. At Road ATL last month I hit 1.18 on Michelin SS. I just figured 1.3 was attainable when I go to slicks.

I only hit mid 1.2's with R-Comps at Road Atlanta. Even so, they weren't sustained for that long.



does that hold for others as well

I'll give you $1000 if your g-meter EVER hits 1.3 and a tree is not involved. Haha

RyRidesMotoX
08-13-13, 11:09 AM
I'll give you $1000 if your g-meter EVER hits 1.3 and a tree is not involved. Haha

I'm so going to try this in a giant empty parking lot near my house.

PISNUOFF
08-13-13, 07:23 PM
You may be able to whip it sideways and it might spike that high when it catches, but the $1000 for it even hitting 1.3 was for liqidvenom. Lol

vms4evr
08-13-13, 08:26 PM
The issue with the LS3 also holds true for the LS7, which is a shame. A number of folks have blown up LS7s in C6 Z06s. Long fast sweeping turns, a much lighter car, and sitting on extremely fat Hoosiers, running the motor way up in 3rd. Or worse the guys who have tried banked tracks for fun, like Daytona, doing the Rolex course. I think the Caddy is too heavy and you just can't get enough Gs on it for sustained periods. Road Atlanta doesn't have long sweepers. It's a damned fast track and scares me more than most with that last crazy-ass turn. I think VIR in hog pen or the Glen in the sweeper after the bus stop strains the oil from draining back worse. Also Sebring on the last turn. Again all those assume you have really good grip. Street tires would be sliding long before you starve the motor.

In my C5 Z06 I have a modded, after 50K miles, LS6. All top end. Heads, intake, cam, rods, timing chain, oil pump, headers. Dyno came out to about 456/rwhp. Red line is set to 7000 (could go to 7200-7400). I try not to hit it much but I do in 3rd some of the time. No oiling issues or starvation. I run no sump but I do have an oil cooler mounted in the nose. So running about 8qts in the motor. My power band from 4-7K looks and feels great. The car is also stripped and weighs in about 2800lbs empty. Coil-over suspension with poly bushings and Wilwood brakes. Corner weighted and max camber we could get running on Grand Am Continentals (Hoosiers) or Hoosier A6/R6 scrubs.

The LS6 loves track duty and will take it all day long. Just bring about 1 qt of oil to replace. They tend to blow by a lot even with a catch can setup. But they don't blow up!

thebigjimsho
08-14-13, 09:10 AM
You may be able to whip it sideways and it might spike that high when it catches, but the $1000 for it even hitting 1.3 was for liqidvenom. Lol

Including V2s?

Jeff James
08-14-13, 11:14 AM
LS3 would be a better DD and still leave you grinning from ear to ear every time you get in it. I def. second this notion. The LS3 has way more potential for gain. Run your LS6 until it breaks!! Suggest getting a GM reman.(may have some new ones still) LS3 GS engine and Intake. You will have the coveted Dry sump (DD may have space issues to add a DS tank) and a 12m/12k warranty. Do NOT buy it from Summit or Jeg's unless you want to get F'd on the warranty. An LS3 with hot Cam or even ASA will be way more docile (ie: driveable) on the street and go like hell on the track. It will also have much low end Tq than a heavily modded 400*RWHP LS6.
BTW- The new Z28 will have an LS7 and the Dry sump is std. Not sure where the tank is though.