Rob99z28

iTrader: (3)

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

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

iTrader: (3)

i was just gona rehone the block n just get forged pistons and maybe eagle rods

2000PewterT/A

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

do a 383 stroker kit from TSP .

2000PewterT/A

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. It’s a great option but I can build a forged iron block for a little less than it would cost for the stroker kit.

I8UR4RD

iTrader: (16)

doesnt matter. either way if your only going to make 500 wheel, either block will hold it fine with a lil love.

bww3588

iTrader: (49)

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

iTrader: (11)

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

iTrader: (49)

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

iTrader: (49)

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

iTrader: (11)

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

iTrader: (2)

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

usmcpi

iTrader: (2)

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

iTrader: (49)

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

iTrader: (11)

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

iTrader: (49)

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 **** right?

bww3588

iTrader: (49)

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

iTrader: (2)

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

iTrader: (2)

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.