GST

Hi All
New guy here
I bought a '99 LS1 5.7 long block that has 70,000 miles on it. It was pulled from the car because it lost oil pressure. When I went to pick it up the previous owner had pulled 1 main bearing cap and 1 rod cap to check the bearings. They were fine.
My question is, can I just re torque the rod bolts and be good to go?
If not, is it possible to change the bolts without pulling the pistons?
Thanks in advance
Greg

garygnu

you can change the rod bolts while leaving the rod and piston in the block.just do 1 rod bolt at a time.get some kaltech rod bolts ,these seem to be the only rod bolt that dose not cause any out of round with the big end of the connecting rod.these are cracked rods and it seems that removing a rod cap is not a good idea.

Austinma62

Im thinking the stock rod bolts can be reused but don't quote me on that. And yes its possible to install new rod botls. You just have to be carefull not to let this piston fall out as you change the bolts out.

bww3588

iTrader: (49)

They are apart, they will never seat back where they are. If you put it back together, your asking for problems.

JakeFusion

iTrader: (7)

Yep - can't simply rebolt them and go after the cracked rod has been apart... You'll have bearing failure pretty quick.

kenp

iTrader: (9)

Rod bolts can be reused. They are not torque to yield. However, it probably would be advisable to at least upgrade to newer GM bolts.

GM disassembled thousands of these engines under warranty to solve the oil consumption issue by pulling the pistons, replacing the oil ring, and reassembling them. You can upgrade the rod bolts if you wish. Why one aftermarket rod bolt would cause a deformation of the rod end and another would not is a mystery.

The question remains though, what caused the low oil pressure?

ZQ8LS1

iTrader: (3)

Another LS1 tech old wifes tale.... LOL

ZQ8LS1

iTrader: (3)

Why wont it ???

GST

Thanks for the input.
I'm hoping that when I pull the oil pump I will find an obvious failed O ring or stuck bypass valve that is supposedly a problem with some stock oil pumps.
I will replace the oil pump regardless of what I find.
Greg

garygnu

check texas speed for oil pumps and O-rings.

GST

I'm probably not seeing the obvious but unless the bolts have a amount of stretch at a certain torque wouldn't it be more likely that you would recreate an accurate cap position with the original bolts rather than changing the bolts and possibly having them not position the cap in the same relationship to the rod.

GST

Will do
They are supporters of this forum aren't they?

chrisfrost

iTrader: (8)

If this engine had an oil pressure issue and You have the engine not in any vehicle , now is the time to check all the bearings and/or replace them ,,,,,,chances are there are a bad 1 or 2 in any of the locations .

Paul Bell

iTrader: (9)

GST, welcome to LS1tech! SEARCH will be your best friend around here.

After purchasing this low oil pressure motor, what did you plan to do with it?

KCS

iTrader: (20)

I never understood this either.

redbird555

iTrader: (14)

you dont need to resize the rods unless you install higher strength bolts like arps because they have the potential to warp the bore. if you go with standard gm bolts or katech bolts with new bearings you should be fine

1bigoldman

I do not understand this.

What difference would it make if using ARP vs. stock or katech? On a basic level a grade 8 bolt is a grade 8 bolt, right?or whatever grade is used for rod bolts. We are not talking about torquing to yield so there should not be any measurable amount of stretch. The torque spec is the same isn't it? If you warped the bore wouldn't they be over torqued? So why would the rods need to be resized to change to higher quality bolts??
Yea sure if we are doing a textbook rebuild yes we SHOULD resize the rods. He is wanting to only change the bolts.

Please elaborate with some facts.

Thanks

wildcamaro

iTrader: (15)

OP when you remove the oil pump from the engine pull it apart and check the machined surface to see if it is messed up.

bww3588

iTrader: (49)

First of all, I was talking about the bearing itself, not the caps.

2nd, being tty or not has nothing to do with stretch. Any bolt regardless of material, grade, style...etc will stretch. It's to what degree.

imma_stocker

iTrader: (19)

Cracked rods are meant to fit perfectly back together. Mismatching or putting them on backwards will make bearings fail because the "cracks" don't line up. But they will fit back 100% if you keep them straight.