huggerorange69

iTrader: (7)

Im going to build a turbo 4.8, i have the 4.8 tore down everything looks good, im on a budget so i cant go all out, look at my setup and see if you guys see anything i need to change or add, this is my first ls build so im still getting the feel for everything.

4.8 stock bottom end, gap top rings at .035, use arp head studs, 243 heads ( i need help on valve spring sizes, i hear that the boost can cause valve float), ls9 cam, ls9 head gaskets, ls1 intake and throttle body, 120# smart fire injectors, truck manifolds, on 3 performance 76 mm turbo, i plan on running 15 psi of boost. If the thing melts a piston i dont care i just had this motor laying around for a yr now, i would like to sawp everything to a 6.0 later on. Any input? do's and donts?

huggerorange69

iTrader: (7)

Its going in this pile after i replace half the sheetmetal

SSZ

What year is the 4.8? IIRC you may need an LS2 timing cover to run the LS9 cam. Neat build.

nonosvt

iTrader: (5)

Looks pretty sweet!

Schraders

iTrader: (3)

Awesome Nova, hard top too. If it were mine, I'd do the drivetrain and chassis way before the body. Let those rusty quarters flap in the breeze while you're having fun! As for valve springs on a budget try these

http://www.alexsparts.com/products/L...PRING-KIT.html

$107 complete and they work great out of the box. The LS9 cam is $139 or something but you'll need another $300 or so in parts to make it work on your early motor. I'd think about the stock cam for now if you're really on a budget, the fuel system and suspension/brakes eat up a lot of your money.

huggerorange69

iTrader: (7)

It's a 2003 motor, I forgot about the ls9 needing a different cam sensor, is there a good out of the box turbo cam out there for a smaller engine like the 4.8?

Atomic

iTrader: (37)

You are going to have a ton of blow by with that much ring gap. I would suggest something closer to the 0.028" range.

huggerorange69

iTrader: (7)

Well I wondered about that, I read another guys build thread he said that's what he gapped his at. Is there any need to do both the top and 2nd ring?

Atomic

iTrader: (37)

He probably did that because one of the magazines that pushed the 4.8 gapped theirs huge. Its not needed in my opinion, even 0.028 is more than you need IMO. I would do a top of 0.024 and 2nd 0.022

oneoverwrx

iTrader: (1)

.022 here and 731whp through a th400. Good luck with build!!

stock48

iTrader: (17)

The fuel has a lot to do with the amount of gap you can run. Gas requires more gap than E85.

huggerorange69

iTrader: (7)

What cui and heads?

LilJohn

Find out which hole has the widest gap and em to that. The purpose of it isnt to open all og them up wide...just check for tight ones. Ive torn down 3 that had 2 or more holes .014 or tighter.

BOBS99SS

iTrader: (2)

731whp on a 4.8? Thats crazy,what is the average guys are making with the 4.8?op whats your goal

huggerorange69

iTrader: (7)

I dont really have a hp goal, i just need for it to last atleast half a season, My nova should weigh 3000# and i need to run 6.20-6.0's in the 1/8th to be competitive. Its a true street type class once a month, im just sick of bracket racing and this class looks fun and i figure i wont go broke building a 4.8/ turbo setup. I may start a build thread im not sure yet

huggerorange69

iTrader: (7)

ok thats good info, thanks

huggerorange69

iTrader: (7)

Are the 243/799 heads worth the $400-500 im going to have to give to buy a set, or will my 862's be ok for the time being? i plan on cutting my teeth on the 4.8 for now and moving up to a 6.0 later on anyways. I want the car to run good tho, im not looking for 450 rwhp im looking to make closer to 575-600

a4ls2goat

whatever you do, do run e85 if possible and the motor will live if tuned correctly

T76s10

iTrader: (6)

I got smart fire 120# injectors to and curious to see how well they work because no one has them

huggerorange69

iTrader: (7)

I have bought a cam for my 4.8 here are the specs- 239/239 duration .623 .623 lift 115 lobe separation what valve spring do i need? I plan on turning this thing around 6800 rpm and running 15 psi boost, im looking at the kit from brian tooley racing good to .660 lift. What are your all's opinions