View Full Version : Rebuilt ls1 or Lq4 swap


Rob99z28
07-22-2012, 12:17 AM
I have ran compression test on the car and i have 2 bad compession levels on #5 and 6 and i know its my rings because of the amount of oil ive been burning. Ive been reading and reading trying to compare and debating on the lq swap and Ive seen the cam an head mods hp between the two are close and here is my question

The Car is cam only now and plan on adding 243s and a 125-150 shoot. All streetable car goal 425-450rwp without nitrous and a lil over 500 with. If i use the ls1 ill forge the pistons and freshn it up or should i just use the lq4 and would the number be the same with a stock bottom ls6 intake, 243s and a 125-150 shot?

4kiro
07-22-2012, 12:25 AM
I would go with the forged LS1. If you do that then youre gonna be set-up for a big shot of N02. If money is an issue then look into a 5.3.

Rob99z28
07-22-2012, 12:30 AM
i was just gona rehone the block n just get forged pistons and maybe eagle rods

2000PewterT/A
07-22-2012, 04:13 PM
I would go for the forged ls1, I have a forged 347 and I love it, it will handle a 200 shot all day long and I don’t have no2 rings so I don't go anymore than that but they can handle more if you run n02 rings. Unless you want to go all out I see no reason not to keep the ls1. Just get a really good set of heads, if you’re staying with stock castings get them ported trust me it’s well worth the money, and get a cam matched to your setup. If you do that you will have exactly what you want.

garygnu
07-22-2012, 06:38 PM
do a 383 stroker kit from TSP .

2000PewterT/A
07-22-2012, 07:46 PM
do a 383 stroker kit from TSP .

I almost did that, but after the price of the kit, plus the extra machining cost to clearance the bottom of the cylinders for the extra stroke it was too much. Itís a great option but I can build a forged iron block for a little less than it would cost for the stroker kit.

I8UR4RD
07-22-2012, 08:09 PM
doesnt matter. either way if your only going to make 500 wheel, either block will hold it fine with a lil love.

bww3588
07-23-2012, 03:13 AM
Do the 6.0 swap. Rebuilding an ls1 is a thing of the past. If you do a 383 you'll regret it when a car with a 6.0 blows your doors off.

usnfenix
07-23-2012, 03:56 AM
Do the 6.0 swap. Rebuilding an ls1 is a thing of the past. If you do a 383 you'll regret it when a car with a 6.0 blows your doors off.

not true sir, simply not true.

OP do the forged ls1. lq4 is a 6.0 almost exact same as the lq9 just they are both iron blocks and the lq4 is lower in compression and geared more for FI setups.

bww3588
07-23-2012, 05:04 AM
Actually, it is true. The lq4 is geared for trucks. Not for blower builds.

However, he already said he will add 243's which will gain back the compression lost to The dish of the lq4 piston.

Also, why rebuild an ls1 when you can put the same money in an iron 6.0 and make more power with more reliability and better driveability?

What happens when he gets the block to the machine shop and they find that the cylinders won't clean up with a .005 hone? Guess what? The block is basically junk and he has a rotating assembly that he can't use.

bww3588
07-23-2012, 05:06 AM
With the abundance of 6.0's hitting the junk yards and prices coming down on them, there is no reason other than weight to stick with an ls1 if you have plans outside simple heads and cam.

usnfenix
07-23-2012, 05:16 AM
Actually, it is true. The lq4 is geared for trucks. Not for blower builds.

However, he already said he will add 243's which will gain back the compression lost to The dish of the lq4 piston.

Also, why rebuild an ls1 when you can put the same money in an iron 6.0 and make more power with more reliability and better driveability?

What happens when he gets the block to the machine shop and they find that the cylinders won't clean up with a .005 hone? Guess what? The block is basically junk and he has a rotating assembly that he can't use.

ok kid yes the lq4 is a production motor for suv's and trucks but here on ls1tech we use them for high hp FI setups, same with the lq9.

if he is adding 243's might as well just put them on the ls1 and have an aluminum motor that is lighter than an iron block that he really doesnt need. hes not trying to go FI or run a heavy shot, he wants under 500rwhp which an aluminum ls1 is perfect for. hundreds of ls1's on this site are making 450rwhp to 500rwhp with a nice heads/cam setup that is very streetable. my ls1 camaro was heads/cam and made 472rwhp and had no drivebility problems, and was my dd. as far as making more power based on the idea of it being a larger engine thats only a valid statement if he was talking about a choice between two stock motors. the power difference between the two is minimal. he can easliy hit his power goals while maintaining a lightweight engine.

and if he takes it to a machine shop and finds the block is fucked, oh well pick on up on ls1tech ive picked up two both under 300 bucks. it really is not all that hard.

OP, do what works best for your goals and take in account all advice given.

usmcpi
07-26-2012, 01:47 AM
Do the 6.0 swap. Rebuilding an ls1 is a thing of the past. If you do a 383 you'll regret it when a car with a 6.0 blows your doors off.

Do you not understand the 383 has MORE displacement than a 6.0? Its simple math really, 383 > 364.

usmcpi
07-26-2012, 01:49 AM
Actually, it is true. The lq4 is geared for trucks. Not for blower builds.

However, he already said he will add 243's which will gain back the compression lost to The dish of the lq4 piston.

Also, why rebuild an ls1 when you can put the same money in an iron 6.0 and make more power with more reliability and better driveability?

What happens when he gets the block to the machine shop and they find that the cylinders won't clean up with a .005 hone? Guess what? The block is basically junk and he has a rotating assembly that he can't use.

You also seem to contradict yourself here. You say dont get a 6.0 because its for a truck. Then say why rebuild the ls1, get a 6.0. WTF?

Also, the lq4 is an AMAZING budget boost option considering its 9:1 ish compression ratio.

bww3588
07-26-2012, 02:27 AM
Not contradicting myself, simply stating the actual intended use of a 6.0 truck engine. If it were in fact geared for boost, it would have factory forged internals.

Also, I do understand simple math, however it appears to be you who does not understand more cubes does not mean more power in all cases.

A solidly built 370 will run right with and past a similarly built 383 in most cases. The longer stroke of the 383 allows the power to be made sooner in the powerband, but generally less peak power. The 370 with the larger bore and shorter stroke will bring power in later but have more overall.


It's simpla math really. If you don't believe me, look around the dyno section.

usnfenix
07-26-2012, 04:07 AM
Well take your "simpla" math to a BMW forum. You have been wrong in every post made in this thread and other members have called you out on it. Lq4 is a great boost motor and cost effective as well. And rebuilding an ls1 for N/A builds can have great results. You can't really claim that one ls motor is faster than another unless we are talking strictly stock. One guy can buy an ls3 and port the heads while another can get an ls1 and heads/cam/intake it and blow the doors off the ls3. Its all about HOW YOU BUILD THE MOTOR. Not simply thinking oh well that motor is ten years old it must suck.

bww3588
07-26-2012, 04:48 AM
I see reading comprehension is not your strong suit either...

Not sure what BMW's have to do with anything either.

My point was, which is valid in any respect was why build an ls1 with the same internals when you can build a 6.0 for the same? Why? Give me one good reason.

He doesn't need it for what his goals are? Huh? I've never heard anyone complain about making more power than they hoped for.

Wrap your head around this...a stock lq4 with a cam will meet or exceed his power goals! Holy shit right?

bww3588
07-26-2012, 05:11 AM
I also never said the ls1 sucks...regardless of it's age. But when it comes to a person debating on an lq engine or an ls1, the only real reason to stick with the ls1 is weight. In which case, since it is a daily driver he won't even notice the extra 100 lbs, but he will notice the extra power.

I still fail to see where I was wrong, however, I do see where 2 different schools of thought are being stated, which I can come up with just as many reasons as you can to why our thoughts have merit.

I agree either engine will work for this particular case. My point was, why build the ls1 when you can put the same money in a 6.0 and have more power? Or you can build the 6.0 with a smaller cam that is easier on the valvetrain (since it is a dd of course) and make the same power?

Prove my point wrong and I will bow out.

usmcpi
07-26-2012, 12:31 PM
Not contradicting myself, simply stating the actual intended use of a 6.0 truck engine. If it were in fact geared for boost, it would have factory forged internals.


Well that's funny...why don't STi's come with forged engines? Oh, and if you say that's a Subaru and not a GM, then why doesn't the 09+ CTS-V supercharged LSA engine have forged pistons?

usmcpi
07-26-2012, 12:38 PM
I agree either engine will work for this particular case. My point was, why build the ls1 when you can put the same money in a 6.0 and have more power? Or you can build the 6.0 with a smaller cam that is easier on the valvetrain (since it is a dd of course) and make the same power?


Duration has no effect on the drivetrain. You can have a 220 duration cam and a 250 duration cam, both with .600". How will the bigger cam have any more negative effects than the smaller cam? In addition, its not the lift of the cam that stresses the valvetrain either, its the lobe profile. So you could have 2 identical spec cams with the same duration, lift, lsa, etc but different lobe profiles. Each lobe profile performs differently and has suitable applications, and will make different power throughout the rpm range.

DeltaElite121
07-26-2012, 12:39 PM
I'd say get your current block checked out before dropping any money. If it's rebuildable/good block core - then figure out what you'de like to do with your money. There will always be 6.0's in the yards for many years to come, but having the money to build the motor you want might not always come easy.

That's what I'd do, anyways.

bww3588
07-26-2012, 01:03 PM
Wow...lift and duration have nothing to do with the valve train....now I've heard it all and can die a happy man.

Oh an the lsa has good enough internals to last the warranty. That's like asking why GM put the 10 bolt f bodies and saying it's a "performance" rear end.

BODUKE
07-26-2012, 10:51 PM
Lq4 might make just as good power as an ls1, but the extra 100 lbs will show fast in a race. I am getting an 383 Stroker in my Z

usnfenix
07-27-2012, 12:48 PM
Bww- I'm on my phone and text is small so your shit reads "BMW" hence why I said to take your BMW elsewhere. Also mobile version of ls1tech doesn't show signatures. Back to the arguing. My reason for op not building an iron 6.0 is the same as stated above, its heavy. And correct me if I'm wrong but in previous posts I thought you were spouting about the lq4 not being a motor setup for FI? Yes as stated a billion times we all know the lq4 was a truck and suv motor. Cool beans right? I never said the lq4 was a factory intended boost motor. Again, here on ls1tech we USE them for boost due to their low compression and iron blocks. I don't get why your still arguing that. Just because it doesn't have forged pistons from the factory doesn't mean you should never boost it. Now back to the point. The op wants mild power to the 450 range. Easily attainable from the ls1 he already has. Hence he can save more money and build it up. I mean if the blocks good why toss it and buy another one if it ain't broke. He can easily heads and cam his current motor and make his power goals while maintaining drivebility. IMO he'd spend more money in a motor swap than building his current motor. And if his block is fucked then pickup another ls block there cheap and easy to find. All I'm saying is if his power goals are low and in the 450 range why build a heavier motor adding more weight to the front not to mention the heat soak an iron block becomes, when he can build a lighter, cooler ls1 and still have his power goals. Yes he'd have even more with the 6.0 not denying that but is the additional weight and reduced cooling ability what he really wants? either way I'm done in this thread OP you will have dozens of people telling you different things just so what seems right to you.

bww3588
07-27-2012, 04:38 PM
Well said sir, well said. I can agree to disagree as both of us seem to have valid points. Good debate.

thompson
07-27-2012, 04:57 PM
We have motors rated to 600HP ready to make the 450HP you are looking for and warranty even with the Nitrous on the motor starting at $1519 in short block form. (Iron 5.7 with new TMS pistons, GM crank and rods, Clevite main/rod bearings, Durabond Cam bearings, Balanced, assembled, and ready to install). We also have aluminum 5.7's starting at $1799.

mjs1012
07-27-2012, 05:02 PM
We have motors rated to 600HP ready to make the 450HP you are looking for and warranty even with the Nitrous on the motor starting at $1519 in short block form. (Iron 5.7 with new TMS pistons, GM crank and rods, Clevite main/rod bearings, Durabond Cam bearings, Balanced, assembled, and ready to install). We also have aluminum 5.7's starting at $1799.

i was looking on your site and you guys have some great prices.

thompson
07-27-2012, 06:54 PM
i was looking on your site and you guys have some great prices.

We try to be as competitive as possible so that we can give the consumer the best product available. Feel free to call or PM us and we can set you up with what ever you need.

usmcpi
07-29-2012, 03:23 PM
Wow...lift and duration have nothing to do with the valve train....now I've heard it all and can die a happy man.

Oh an the lsa has good enough internals to last the warranty. That's like asking why GM put the 10 bolt f bodies and saying it's a "performance" rear end.

Why do you think Comp Cams has like 20 different lobe styles available? Some, such as the Marine lobes, are gentle while others, such as the LSK lobes, are harsh and tear the shit out of valvetrains. Looks like you need to research cam design.

So the LSA cast pistons are good for boost but the cast lq4 pistons are not...please do explain.

usmcpi
07-29-2012, 03:29 PM
Bww- I'm on my phone and text is small so your shit reads "BMW" hence why I said to take your BMW elsewhere. Also mobile version of ls1tech doesn't show signatures. Back to the arguing. My reason for op not building an iron 6.0 is the same as stated above, its heavy. And correct me if I'm wrong but in previous posts I thought you were spouting about the lq4 not being a motor setup for FI? Yes as stated a billion times we all know the lq4 was a truck and suv motor. Cool beans right? I never said the lq4 was a factory intended boost motor. Again, here on ls1tech we USE them for boost due to their low compression and iron blocks. I don't get why your still arguing that. Just because it doesn't have forged pistons from the factory doesn't mean you should never boost it. Now back to the point. The op wants mild power to the 450 range. Easily attainable from the ls1 he already has. Hence he can save more money and build it up. I mean if the blocks good why toss it and buy another one if it ain't broke. He can easily heads and cam his current motor and make his power goals while maintaining drivebility. IMO he'd spend more money in a motor swap than building his current motor. And if his block is fucked then pickup another ls block there cheap and easy to find. All I'm saying is if his power goals are low and in the 450 range why build a heavier motor adding more weight to the front not to mention the heat soak an iron block becomes, when he can build a lighter, cooler ls1 and still have his power goals. Yes he'd have even more with the 6.0 not denying that but is the additional weight and reduced cooling ability what he really wants? either way I'm done in this thread OP you will have dozens of people telling you different things just so what seems right to you.


A lq4 is only 60ish lbs heavier than a ls1...something you wouldnt even notice especially over the extra displacement and power the lq4 would make.

If you plan on rebuilding the ls1 w/ forged pistons or swapping in a stock lq4, the end cost would be roughly the same. Plus since you already have the ls1 out, you can easily just freshen it up (keep the stock pistons, just new seals, bearings, rings, etc) and sell it for $2k+, which is more than you would spend on a lq4. In the long run, the lq4 will be better for more power. Short term, you can't really go wrong either way.

1BadBlkB1tch
07-29-2012, 04:30 PM
depends on your future setup or idea's lq4/lq9 is a better motor/n20 motor imo and a 5.3 is the better boosted motor and a ls1 is jus to expensive to rebuild i was in same kind of dilemna and i chose a lq9/408 stroked n20 setup

bww3588
07-29-2012, 09:59 PM
The lq4 is just a little over 100 lbs heavier than an ls1. There is a thread in the sticky where someone weighed the blocks. Either way, you are right, You probabtw wouldn't notice it unless bracket racing.

On The note of cam lobe design, yes, lobe profile determines your VO and VC points and ramp rates, which do play a major role in what kind of stress the valvetrain is under, however, lift and duration are also major players in that game as well, and to say they don't is just ignorant.

usmcpi
07-30-2012, 02:52 AM
Yeah, sure if you had a cam with .650" lift while running .600" lift springs you'd be in trouble, yet with a decent (not harsh) lobe profile running .6" lift on a .65" spring, i fail to see any problems. However a harsh profile such as the LSK would still eat those springs over time.

bww3588
07-30-2012, 03:01 AM
Agreed. Again, good debate.

raptorblackBird
08-06-2012, 06:07 PM
I just bought stock 5.3... Why are they good?


Posted from LS1Tech.com App for Android

brucer
08-07-2012, 03:34 AM
I just bought a high mileage lq4 for $400 to replace my ls1. I tore the lq4 down today, it looked good internally,very good for the miles on it..

I'm planning on reringing the lq4, use the heads off my 98 ls1, mill the heads about .010-.015 or use a thinner head gasket, add ls6 valve springs and probably an asa or hot cam, and a good tune.. It should run strong, have good torque,not be expensive and be a solid street engine...

deonls1
08-13-2012, 11:54 AM
Very helpful info here keep it coming.

deonls1
08-21-2012, 01:58 AM
Since you can make 450 wheel on a h/c ls1. How much nitrous can you add on top of that on a stock internal engine?

NemeSS
08-21-2012, 06:21 PM
wun mirrion hosepowaa