Gonna lightly go thru my 4.8 Gen3 turbo. My thought was forged pistons with the proper ring gap, ARP Main studs and rod bolts, and clean up the block/heads. I'll throw in main/rod/cam bearings too.

Wondering what kind of boost I can push with that setup. Feels like a common setup I just couldn't find a thread with those specifics.

The rods are the later gen4's with floating pins. The intake/tb will remain a stock truck as well. Cam is a elgin "sloppy stage2". Turbo is an ON3 76/69, might step up to a 78/75. I'll run 93 oct with a walboro 450 pump. Injectors are sd80's but I might go to ID's probably the 1050's... unless I can go bigger.

 

Until it blows? I've been 32 PSI on gen 3 4.8 rods, but the boost number is irrelevant and doesn't correspond to anything directly.

 

You are going to run out of octane before you find the limit of Gen 4 rods.

 

Rod bolts are a waste. Otherwise, get after it.
IMO, sell them little turbo and go with a bigger turbine (bigger than the 7875). I made the jump with my s475/83 T4 to an s475/96 t6 and the difference in power was unreal. Don’t worry about late either, this t6 spools as fast as the T4 did, I’ve got logs to prove it.

 

ARP Rod bolts are not only a waist but they may be detrimental to strength of the assembly. I’ve had two seasoned engine builders tell me to stick with factory rod bolts.

 

I thought rod bolts were the next weak link past the piston. Guess I’ll do a little more reading.

agreed about boost number limits, should have been more clear I was thinking rwhp, sorry about that. I guess I was also wondering with my cam/heads/intake/turbo/ect where my rwhp limit is assuming I could boost it to xxpsi before something complains.

not sure where I’ll land with compression just yet. Pretty sure I’m around 9.5, probably stay right around there, I’ll need to pick out the pistons first.

gotta stay with a t4 for now and see what happens, currently this truck has about 0 lag with this turbo, also have roughly a 3200 stall in the converter too so I get past the cam quickly.

 

can ya get e85 there? by hook or by crook, get some.

 

The rod itself is the weakest link, then the piston, and then maybe the bolts or the crank.

 

I wish, nothing near me and this is a 3 season daily so I have to run 93.

The goal is to run ~500rwhp 80% of the time and to turn her up occasionally. based on my current dyno numbers I’m thinking that is about 14psi of boost with my current config.

I see 800rwhp is doable and reasonably safe as long as the tune is good for an Abe but I’m not sure if I just need to turn her up or if there are a few pieces of my current config that I should be looking at to ensure it’s safe (ish) and it’s not a bottleneck. One piece I think I’ll need to look at is my intercooler, it’s a $99 eBay special and I don’t think it flows enough. That said, Taking suggestions for a IC that fits between the frame rails of a C10…. Can’t do a high front mount as my AC and tranny cooler occupy the space in front of my radiator.

After reading a bit about the ARP rod and mains I guess there are a number of guys just rolling stock hardware and not having a problem. During my research I found a few guys not being worried about the pistons too.

My thoughts are the first problem I’ll run into will be rings lifting a land under heavy boost so I’ll need to gap them properly. The next weak like as I understand it is the piston so I figure while I’m in there why not…. It’s just $$ and it’s not a huge expense. Once I solve my ring and piston potential weakness I figured I’d solve for the rod problem which is the rod bolts not the rod. I get it’s more of a RPM/rotational weight factor and I do not intend to spin it north of 6800-7000 max so maybe I’m fine… but here is the thing, I don’t have a problem spending the cash to buy the hardware and resizing the rods, just want to know it helped keep this build together. Same deal with the mains, if I can turn it up enough to hit 800rwhp I want to know my mains aren’t walking.

So if the rod bolts and mains are happy at this power and rpm range then I’ll save a few bucks and run OEM hardware. If the ARP hardware with associated machining adds more confidence at 800rwhp then I don’t have a problem spending the cash. Of course if I find I need to work the rods/crank then I’m in a might as well situation so I’ll buy the ARP hardware due to extra piece of mind!

 

The rod bolt is not the problem, it’s the overall strength, however, good rods bend too! I’ve never seen (anyone else’s or my own) **** break a rod bolt. Most times (99% of the time) the rod snaps and the big end of the rod is still hooked to the crankshaft fully intact.

 

If you're doing pistons may as well do a set of rods too. They're cheap enough, I'd replace the whole rod before putting arps in stock rods.

you are currently standing at the entrance of the rabbit hole, enter at your own risk.

 

I’ve dived down the rabbit hole countless times and found the rabbits to be a lot of fun to hang out with. I Just want to make sure I get the fun I pay for.

Starting to sound like I should just clean it up, gap the rings, and turn it up. This concept is a long way from the previous world I played in so I’m fighting with the feeling of needing to do something.

Thanks for all the comments

 

Get new GM stock rod bolts, if its a 4.8, you should have part # 11570662. They work just fine, 8k rpm fine. I only replace them when I don't know the history of the engine or I have torqued them more than 5-10 times. The stock GM rod bolts torque to a higher value than any of the ARP replacement bolts for stock rods......Don't believe me? Torque the stock rod bolts with the torque angle method then grab a regular torque wrench and check how much torque you would need to tighten that bolt further.

Stock rods work too, they are hard to break and have much better fatigue strength than most aftermarket H beam rods. (Read: they will usually just bend when you damage them, aftermarket H beams such as eagle will randomly snap after you damage them) They also work just fine to 8k rpm. There is a reason aftermarket I beam rods are more expensive and heavier than H beam rods. Stock rods are I beams.

Stock pistons are good, they only fail from knock or tight ring gap. The OE Mahle (not the performance Mahle) pistons work too, they are the same thing as stock pistons. I don't even have knock sensors.....

You will be fine.....unless your're trying to make peak torque at 2,000-3,000 rpm on fuels such as E85 (no knock is present). The import tuner guys like doing that for some reason and blame stock parts for not holding up.
The truth is many engines have rotating assemblies that are much stronger than the low to mid range aftermarket stuff (the cheaper stuff).

 

I have stock gen3 5.3 bottom end and making 900tq and 827-ish HP on mustang dyno.

My bottom end has arp rod bolts and rods were resized for them. no, I did not waste time to put them in there BUT my motor seems to hold up pretty good. Not sure what’s the secret to it but maybe the rod bolts help. I’ve revved to 7500 fine and turned rpm down due to spinning worst (added timing up top to hold power) 93 pump gas with M1 spray after 4psi.

 

Come to think of it, your absolutely correct. All stock rod bolts was not the weak point. It was the ring land or rod with a bad tune.

 

are you pushing any water with our setup and are you running stock style heads.If you are running stock heads what kind of boost and how are you keeping the heads on the engine without pushing water...thank you

 

sorry when I see thngs like this I have to ask are you running stock style heads and if so how are you keeping them sealed up so they dont push water

 

stock 706 heads with btr stage 2 cam kit. Arp head studs. I think I have some aftermarket rocker trunions but not 100%. Have 0 issue with coolant. Ls9 gaskets.

 

so your using copper coat on the ls 9 gaskets.I had one guy tell me he put copper coat on his as well.I looked at the copper coat but your have those who say not to run it on a mls style gasket.Im just looking into anything that will keep this thing from pushing water.At 21 psi what kind of timing do you have im not sure if im getting to aggressive on timing or not

 

If you are running stock head castings, don't rule out that they might just have a crack somewhere.