zachand799

Hello guys, i’m sorry if this type of thread has been beaten to death but I need somebody to literally tell me what to buy because I cant make a decision.
got a 04 iron block 5.3. honed it, bore is still 3.78. 243 heads. going to run btr stage 2 turbo cam, off brand 66mm t4. got everything but need to order pistons and rods. EVERYBODY has a different stance, some say stock rods will be fine i’ve already spoken to wiseco got a part # for the piston they recommend for the setup I have with stock rods (941 I think) and I also have a part number for pistons to go with diff rods (927 I think). pistons for stock rods look like $1k. can i trust new stock rods for 600hp right now and maybe a bit of a bigger turbo down the road ? or do i really really need to just swallow and get better rods and the different pistons ?
thanks,
Zac

Kjduvall

id bite the bullet and get a summit racing pro ls forged piston/rod kit. then that'll be the last thing you have to worry about, thats my .02 cents worth.

Damian

iTrader: (89)

Gen 3 stock rods will hold 600-700rwhp no problem. Guys have been pulling 300K 5.3's out of junk yards and hitting them with 15psi with no issues. Gap the rings accordingly per your application and let it eat.

RonSSNova

iTrader: (3)

Just get new rings and run what you have. It will be fine.

grinder11

iTrader: (1)

Yup, I agree. If it was N2o, that might be a bit different story. But it's not, so it isn't. Amazing how strong these engines are w/OEM components.....

zachand799

hoping somebody will give me some more advice, bit the bullet and got K1 rods, wiseco boosted pistons for 3.78 bore, i’ve got most of the short block put together no issues. on ring gap stuff, the paper from wiseco says boosted/nitrous applications prefer top ring to be 0.050 and bottom to be 0.055……. I did some math and ran it by some people and figured 0.019 for top ring and 0.021 for bottom ring. what is an acceptable gap difference ? 0.004?
a couple (cylinder 3 was bottom ring 0.025 top 0.020, cylinder 4 was bottom 0.023 and top 0.024) were a bit off.
did I F-up ?
SOS.
disclaimer I have never put a motor together this is all rocket science to me.

LS1Formulation

iTrader: (13)

I think you meant to type .005 per inch of bore and .0055 per inch of bore, correct? Let's just say this: You're never going to notice if your ring gap is too big, but you definitely will if it's too small. It'll be fine, but just remember when gapping rings, you have to check them often and grind small amounts at a time so you don't overshoot. You *might* be able to swap the rings between cylinders and make up a thousandth or so, but that depends on the tolerances in your engine.

zachand799

thank you for the response, i’ve heard random things about oil getting past if the ring gap is too large. and every website (wiseco included) doesn’t specifically say how much is too much just that “care must be taken when gapping rings” 🙄 and I also still am fuzzy on the ring clocking technique; won’t the rings rotate when they’re in the block ? does it truly matter about the clocking ?
thanks, Zac

LS1Formulation

iTrader: (13)

It's better to be precise, of course, but if you're a couple thousandths too large, I wouldn't sweat it. Yes, rings DO rotate in the bore, the whole point in clocking them is to give them the best chance of not having the ring gaps line up. So is it important? Somewhat. Eventually they'll line up, and just as quickly they'll rotate away again. One thing you don't want to do is have your top gap be larger than your second ring gap, as this can trap combustion pressure between the rings and cause ring flutter/oil control issues.

G Atsma

243/799 heads came on some Gen III and all Gen IV 5.3 engines, which all have 3.78" bore

dw456post

Dang it---Thought I deleted it quick enough