Zerex

I'm trying to decide which LS motor to start with to do a JY blowthru project. Hoping to make somewhere around 700hp (thinking 76mm turbo) on a shoestring budget
Local motor prices are higher than most area's, but I got prices of $700 for a 5.3 or $1200 for a 6l (lq4).
So I'm looking for opinions on whether I should bite the bullet up front and spend the money on a 6L or if the 5.3 has any benefits and might give me room to grow.
Thanks in advance

alexcoreas

iTrader: (1)

Subscribed. Going to my local JY Friday. Picking up a 5.3 for $400 in California. Its hard looking for a solid build on 5.3 the damn search doesn't help much. By the end of page 12 they always go different routes.

got-a-ls1

iTrader: (12)

well if your on a shoestring budget the 500 dollar savings is certainly useful... depending on the turbo you chose as well the 5.3 might be better. If you get a budget 76 turbo they usually have smaller exhaust wheels which can choke up a 6.0 in the higher rpms.

i am using a 5.3 until i get my ls1 built and i love it. makes plenty of power.

LS1NOVA

iTrader: (12)

What he said. A budget 76 has small turbine which the 5.3 is better suited for. If you have the room do the 6 and a BW S480. If your space limited do the 5.3 and a 76. The 5.3 cylinder sleeves are much thicker but cubes does make power too.

Zerex

Turbo will most likely be a Magnum 76mm Q trim with the .96 a/r
But i could also go BW s475 with the 1.32 a/r.....just want to be able to make 700hp

FAST LS1

iTrader: (2)

From the Hot Rod article it doesn't seem that cubes are as important as the turbo setup, heads, cam etc.

http://www.hotrod.com/techarticles/h...g_bang_theory/

They made 1100hp on a 4.8L, and most use the 5.3L for the thicker cylinder walls and cheaper junk yard price compared to the 6.0L. I'm building a 5.3L right now and shooting for a similar 700+hp.

got-a-ls1

iTrader: (12)

cubes dont mean **** for peak power numbers. For instance look at a supra and many other small turbo engines. They can throw up huge numbers but take too much time to spool to have fun on the street with. Sure a dedicated drag car you can make it work. But if you want a broad powerband and near instant spool its hard as hell to beat a big cuge motor with a properly sized turbo... That said though 700 horsepower also isnt asking too much for a 5.3 turbo with a good powerband.... research whats skinnies has done with a stock 5.3

got-a-ls1

iTrader: (12)

also zerex there is much more to the exhaust side of a turbo then the a/r ratio. Turbine size seems to be often overlooked. Comparing a pt7675 to say a tc76. Both can have a .96 a/r but the tc only has a 68mm turbine vs the 75 on the pt7675.

I bet with the 5.3 and a relatively cheap tc76 you could get damn close to your goal. And if you went with the pt7675 would definitely break reach your goal. I dont know much about the borg turbos. so many different numbers lol but i know they are cheap as well and work great.

gnx7

iTrader: (28)

remember that '05+ engines have better rods. The rods seem to bend beyond the 650rwhp-750rwhp+ levels.... beyond that it is the piston ring lands that fail over time.

Keep it below 700 flywheel HP and it should last a while.... also the RPMs below 6500 too.

2000RATA

Shoestring budget and 700 hp should not be in the same sentence. Your are going to budget this motor into pieces. And skinnies didn't really do a budget build. He has the best stock long block and head combo, ARP fasteners, billet turbo, excellent cam selection, E85 fuel. He didn't budget anything that mattered. He did it smart and there are alot of guys who miss that about his build.

87silverbullet

iTrader: (11)

I agree with all this except the cam selection part. It was only the GT2-3 from Lingenfelter, nothing special.

2000RATA

I may have used "excellent" where "good" should have been used.

headed-ws6

iTrader: (34)

he was also using stock heads which are far from best. As far as the long block goes the build skinnies used was very budget friendly. Fuel and a proper turbo, bov, and wg are what you really need to have. Skinnes didnt skimp on any of that.

got-a-ls1

iTrader: (12)

I never said skinnies did a budget build, i said to look at the power he made with a 5.3 But his motor is stock for all intents and purposes, i guess i dont consider arp fasteners expensive? The billet turbo is not needed at all at 700 rwhp. I have the billet turbo as well but i really dont need it. Josh included it in the kit so i said ok.

skinnies

iTrader: (33)

I definitely spent the money where its needed, overall not a lot in my motor considering it threw down 855rwhp on the dyno and probably made over 900rwhp on my last passes in the rx7. I do run the billet 76 which I paid $1300 for, I did go 8.9's on the tc78 before that though, it was a great turbo up until around 700rwhp.

$600 jy L33
$50 used cam
$250 arp head studs
$230 patriot golds
$50 used pushrods
~$80 ls9 gaskets

Under $1300 for a motor I've beat the crap out of for almost 2 years now in two different cars, can't complain about that! Plus if it lets go(I'm going to guess thrust bearing will eventually die) I'll have the springs, pushrods, cam, head studs to all swap over, just need new ls9 gaskets and a new jy motor. I do cut open the oil filter every time I change oil to make sure everything looks good, highly recommend this to everyone!

This motor has ONLY been on e85, never an on pump gas, we've abused the crap out of it though but with a rock solid tune. I've said many many times, the tune is key to keeping them alive! We've made 180mph pulls on it on the street back to back, no cool down or anything.

2000RATA

Thank you skinnies you confirmed exactly what I was trying to convey. And good luck this year.

Zerex

Sorry, my point was I want to leave the longblock as 'stock' as possible and hit my goal. I'm going to spend money on the small things to keep it alive
I'm hoping my only motor changes will be cam, springs, pushrods and the intake/carb swap. Going with an A1000 fuel pump, 1/2'' feed/return, 94 octane and meth injection. Tuned on a chassis dyno and data logging on my LM1 to keep thing happy

flynbludream

iTrader: (1)

What did you do for injectors?

dell

My project is an unmolested 72 Monte with a 402 BBC. There were a couple of reasons I went with the 5.3 over the 6.0. The first and most obvious was the cost of the motors. Around here everyone thinks the 6.0L is made of gold. When I first started considering the swap I did some shopping and the price was $1500- $3000 depending on the mileage and how complete you wanted the motor.

With that known I started thinking 4.8 and 5.3 as I saw a number of them for just a couple of hundred dollars and almost grabbed a complete 4.8L with 121K on it that the guy was asking $250 for but I would have to pull it myself.

My other consideration is fuel mileage. On a good day the Monte gets 10-12 around town and 15 hwy. I want upper teens to low twenties mpg around town so smaller is better. I'm only looking to make around 500-550HP and I'm going to boost it so I don't need the cubes.

I decided that I would take either a 4.8 or 5.3 and be happy with it. I stumbled across the 5.3 LM7 with 44K for $450 complete top to bottom, front to back. I figure with an LS6 cam and springs and a 72MM turbo I should easily meet my power goals on 7 to 8 lbs and get great mileage on top of it.

To me the 6.0L just wasn't worth the cost.