TXjeepTJ

iTrader: (8)

Which engine for turbo application, 5.3L or 5.7L LS1?
I plan to get a 5.3L 1999-2004 truck, which I then want to do a single turbo - looking to get around 500rwhp.

I currently have a LS1 5.7L out of a 2000 Camaro SS, from a previous engine swap I did.

I have read that the 5.3L would handle the turbo better since it has a lower compression, but then I also heard that the 5.3L isn't a good choice because of low torque and fewer cubic inches.

I would plan on going with forged pistons and rods. Which means I would be able to change up the compression ratio of the 5.7L, unless you think the stock compression ratio is fine - let me know what you think

The catch of all this is, the LS1 block has crack on the exterior. Which means it would have to be replaced (or fixed.. but I don't know if I want to attempt that).

Should I go through the trouble of getting the LS1 back and going, lower the compression and use it? Or will the 5.3L shine more if I were to put the money into it instead of bringing the LS1 back from the dead?

If you were in my position, what would you do?

SPRAYED 01

iTrader: (22)

Don't fix that block. Why risk it. If you only want 500hp go with the 5.3

yelo04goat

iTrader: (11)

5.3 500hp is an easy day...

slow67

iTrader: (2)

If your putting pistons/rods in it anyway, the 5.3 block can be bored to 5.7 specs.

jjcamaro02

iTrader: (34)

I am building a 5.3 bored to 5.7 (3.905) and using D1SC Procharger. My LS1 cracked at about 700 RWHP and this was a cheaper way to get me up and running again. I would not use the LS1 if the block is cracked. Good luck on your build.

TXjeepTJ

iTrader: (8)

does it need to be re-sleeved for that? how much does it cost to bore it out (I've heard of it before and what it is, but never heard of the general cost of it is)

NemeSS

iTrader: (127)

not cost effective or cheap for that repair.
u will spend for what you can get a new 6.0 iron block. and it will always be just a liablity. the 5.3 will handle some psi. 4.8/5.3 have been known to push above 500rw with everything else being correct, tune, fuel etc.

TXjeepTJ

iTrader: (8)

what if my LS1 was in perfect shape (no crack), would you pick 5.3L over it? Might just get a used block (around $400), test it for cracks and use that to rebuild the LS1 up

thanks for the replies by the way! really appreciate it

slowlsx

iTrader: (28)

If all you want is 500hp then go 5.3 and mp70. Hell there's 4.8/5.3's putting down 600-650rwhp pretty reliably.

NemeSS

iTrader: (127)

if it was me. yes.
rebuild the ls1 if thats what you really want. but you can find a complete 5.3 longblock for about that price 400-600$ in running condition.
i have a stock bottom end 4.8 which i plan to push to around 700+rw full trim. and i also have a 5.3 that i will push as much as possible before the 4.8.
the 4.8 has better heads, gaskets, studs.
the 5.3 is completely stock except for upgraded springs and pr

jjcamaro02

iTrader: (34)

I found the block bored out to 5.7 for $175, had the pistons already so it just needed to be honed to 3.905. This was much cheaper than going with a 6.0 block. The block does not need to be re-sleeved and would probably cost a couple hundred to get bored.

kmracer

iTrader: (1)

just get the block repaired. it really shouldnt cost much at all. thats the only issue with the engine right?

kmracer

iTrader: (1)

AL is super easy to fix. you'd be surprised at how bad of an AL block/head you can just weld up.

and the stock ls1 internals are fine at that power level, so is the compression.

slow67

iTrader: (2)

Cast aluminum is a BITCH to weld.....

kmracer

iTrader: (1)

you sure about that? its done all the time...

http://www.youtube.com/watch?v=JBkgJNEStxo

JAX04

iTrader: (17)

interesting right there.

slow67

iTrader: (2)

Have you done it? I have. Just because its done all the time doesn't mean is easy. Porosity and impurities (very common) make cast aluminum difficult to weld (if it can even be welded at all, as some types of aluminum can't).

yelo04goat

iTrader: (11)

x2 on the f@#$ing HARD to weld... thats if you can get it clean enough to get a good weld.

kmracer

iTrader: (1)

a professional would have no problem.

slow67

iTrader: (2)

Go talk to a welder about welding ANYTHING cast....none of them will say its easy....