tonytone4143

i was wondering has anyone changed there pistons and rods for boost? if so whta kind are you running, and compression. i am in the process of the build and i am trying to get all the fact in order so its done one and will last awhile, looking for 650-700 rwhp. i have 80lb injectors, t78 turbo 50mm bov, truck manifolds, gonna order a front mount,etc.. and this is gonna be dd as well. also was wondering should i go with the factory pcm or should i use the fast system?? for tuning? thanks in advance
-Tony

tonytone4143

anybody???

gnx7

iTrader: (28)

You should bore it out so you can run LS1 bore size pistons.

If you are going thru that much trouble though.... just build a 6.0 from the get go. The 4.0" bore opens your options for larger valves which will be less shrouded and flow more. You can't bore out a 5.3 liter to 4.0" inches.

If you have the money aftermarket fuel injection is better.... but factory works with a good tuner.

Wicked69

I would think if your goal is only 650-700hp you would be fine with the stock pistons, rods, heads without much issue. Here is my build and my goal is 800+rwhp in a 69 Chevelle.

5.3 with 64,000 miles running.
Stock pistons, rods, heads
Arp rod bolts, arp head stud kit, ring gap opened, patriot gold dual valve springs, chromoly 3/8 pushrods
XER273 224/230 .581/.588 lift
Twin pt62's/58AR 40mm wastegates, manual boost control, factory ecm
E85.

My plan is to run around 15lbs of boost but less than 20lbs. If I can't reach my goal at 19lbs then so be it. I want it to live for a couple years if I can. From what I understand there is a point where you want to go forged pistons, etc..but I don't think 700hp was it. I think it was around 800. Just thought I would throw that out there.

tonytone4143

i have a friend who already bored out his 5.3 to a 4.0 bore and has has no problems with it in the past year and change. but it's na, and i want boost.

thanks for the info. i think i will overhaul the internalls and see what happens then. you stated to open the ring gap?? to what?? and what is the benifit of this? thanks tony

streetknight2

iTrader: (10)

Not to rip the OP's thread, but I'm thinking of doing a similar build in a G body.

What did you open the ring gap to? I also wanted to run a single turbo instead of twins and run on Gas since I don't have E85 available in my area.

Wicked69

We are planning on opening the top ring gap to .023 and the second to .025. It seems many open it up to .028 or more but since I am running E85 and E85 runs so much cooler I didn't want to take a chance of burning oil or blow by. The main issue seems to be the top ring lands blowing off with boost so therefore, opening the ring gap will keep them from butting together.

On gas it seems the consensus is to open the top gap to the same as the second of .028. I am using stock rods, pistons, piston rings, heads, etc... Just too many people haveing success with the stock bottom end. Of course i plan to run less than 20lbs of boost and that should help with the longevity.

streetknight2

iTrader: (10)

Thanks. I'm still trying to locate an engine, they're kinda high around here. I found a 27K mile out of a 07' truck for $800 with accessories, but no pcm or harness. I want to use stock bottom end too. and run like a single 76mm T4. Gonna put it in one of my Buick GN's. Car weighs 3300 with me in it, hoping to run mid 10's. Gonna use a TH350 trans.

Gfleck047

iTrader: (1)

If u dont have a pcm or harness put a carb set up on it i doin a turbonetics hurricane 78mm with a 750 or 850 blow through with arp rod bolts turbo cam and gold springs. Carbs are just esaier for me to use.. intake and msd box are 650 carb is 450 so it might be a few bucks cheaper

LA WOOSH WOOSH

I got a freind down here in the valley running a 4.8 stock bottom end with turbo works fine hes put down sum 6.0 wit pro charger been a witness to sum races

tonytone4143

not bad