KJZ28

Well awhile ago I was going to sell my worked 5.3 block...I am glad I didn't because my gen 1 chevy in my 78 Camaro went BAM! So now I am going to build up a 5.3L

Anyway I am looking to have 500rwp with a turbo. I will not be putting the turbo in for awhile, and I will run the engine naturally until I have the extra dough.

What parts should I put in? I want it to be good runner, no huge cams. Should I just find a set of stock heads? Or save for a good aftermarket set?

Any input will be appreciated!!!

conan

iTrader: (5)

I would do forged rods and pistons. Before you order your pistons make a choice on what heads you will be running. This way if you run a bigger cc head your piston dish wont have to be a deep. If your going to run a 5.3l head you'll want a deeper dished piston. I would get the compression ratio in the 9.0-9.5 range. As far as a cam I would PM "patrick g" and have him spec you a blower cam for a 5.3l and then have a sponsor custom grind you one.

KJZ28

I like the all forged bottom end. Yeah I am not sure on heads though, its definitely going to be 5.3L heads though.. If I use stock 5.3L heads i can save like $1,000 but is it worth the savings? I dont know. Input?
Where is a good place to get a forged rotating assembly for a 5.3L? I cant find a place anywhere.

conan

iTrader: (5)

Try giving texas speed a call. If they can get you what you need have them figure out what dish in the piston to drop compression down.

old motorhead

iTrader: (10)

Forge the pistons and upgrade the rods. Don't spend any money on the heads. Head studs would be a good addition. For 500rwhp, you'll need 10+PSI. A boost cooler, meth inj, and/or air/air intercooler would be good too. If you're going max effort, shoot for about 8.5 cr. I'd aim for 10 to 1 cr if you want a motor that does well on the street as well as under boost.

nastychevelle

iTrader: (7)

you'll be fine with the stock bottom end people have pushed them way over 500hp (synergy has a twin turbo one pushing 717rwhp on 18psi on stock bottom end) i would do something like this

212/216 .558"/.561" 114 LSA.
arp rod bolts
ls6 intake
ported TB
60# injectors

if you have the money do some stage 2.5 5.3 heads to they would be a nice complement to the setup

as far as turbo setup

T70
tial 38mm WG
you'd be fine with a turbo xs RFL BOV

no need for meth at 10-12psi on stock compression


and A cam like that will not have a lot of overlap so it won't bleed off a lot of boost. It will also have a lot of low end power so you can get into boost quickly. You don't really need to worry about top end power because the turbo will take over at that point.

KJZ28

Thank you very much!!!! I saved that info on my comp! So where should I order the bottom end parts GM, or look for used parts? Because I only have a block. Who sells overbore pistons for this engine?

EDIT: Dang those t70s are nice and cheap on ebay! Thanks for the recommendation!

lo&sloSierra

iTrader: (8)

if you have a crank then just get rods for an ls1 and i think texas speed has an overbore piston now for the 4.8/5.3 block

nastychevelle

iTrader: (7)

make sure its a master power T70 not one of those knock off Chinese units (i'd order it from ModularTurbo here on ls1tech)

if you dont forge the bottom end it would leave money for decent heads or atleast porting on the stock ones

i'd do something like this if you have the money
PRC stage 2.5 5.3 heads (flow 312cfm @.600) $1200 from TSP
custom cam (212/216 .558/.561 114lsa on XE lobes) that will run you 500 with pushrods

so for the same price you'd pay fro a forged bottom end you could have a killer top end

no problem ive done a ton of research on the 5.3 turbo builds cause im planning on one myself if you have anymore questions feel free to ask me

KJZ28

OK thanks for the tip on the turbos. Yea I think $1200 for the heads is not that bad, better than $2k I see in Summit & Jegs. I mean I dont have the money now for the stuff, but I am going to be slowly buying parts as money comes in. So eventually I will have everything! Thanks again for the info!

EDIT: Well if I get the good turbo stuff from modular turbo, I think I would have to use stock heads, IT would have to be one or the other, cheap ebay turbo components or a good set of heads. What would you do?

old motorhead

iTrader: (10)

My experience with 10psi and stock short block wasn't so good. This was on a 5.3 bored to LS1 specs. It was stock except for LS6 cam and forged pistons. Back then, forged 5.3 pistons were hard to come by, hence the overbore to LS1. Lots of options there. I'm sure it was well over 500rwhp, but it was never dynoed. A rod broke and trashed the motor. No way would I build a motor for boost without forged pistons and good rods. 6psi maybe, but not 10+. I too have heard of stock short blocks hanging in good with boost levels around the 10 and up mark. My little GMC is doing well at 9 radix psi on a stock LQ4. I bought the LQ4 cheap. No way would I build a motor for boost with stock components. Forged pistons and good rods aren't that much more money. If you want to dial in a little more boost or spray it a little, you're good to go if the guts are good.

nastychevelle

iTrader: (7)

go with good turbo parts heads can come later
here are some threads that used stock bottom end
https://ls1tech.com/forums/multimedi...ect-pinks.html
http://www.performancetrucks.net/for...d.php?t=435896
http://www.performancetrucks.net/for...d.php?t=432919
https://ls1tech.com/forums/forced-in...it-717-hp.html

old motorhead

iTrader: (10)

What does a good set of heads do for a turbo motor? Is it money well spent? What do you look for in a set of heads going on a boosted motor?

KJZ28

Sweet. I think I am going to buy a 5.3L Donor for a few hundred bucks and take all the parts I need off of it and put everything on my block, upgrade the hardware with all ARP stuff, and get a good valvetrain(like you said), an Ls6 intake w/ bigger injectors.

Now what am I supposed to do with the computer setup? That is the part I am real worried about I tried reading about it, my head started hurting. Could you simplify what I am supposed to do to make this work? I see the fairmont uses a megasquirt, I looked at the website and my head hurt even more.

nastychevelle

iTrader: (7)

well i picked up a 02 truck wiring harness and computer and i have to modify that to work but idk what ill need to do yet.... ill wait till im done before i do that but i know you can pick up a brand new aftermarket harness on ebay for around $325 just type in ls1 wiring harness

KJZ28

ooohhh ill do that...I was getting worried looking at some peopels computer setups, tehy wre spends $1k and more, if that was the case id have to change my plans. I can do $325

nastychevelle

iTrader: (7)

pm me and ill give you the guys name