silversweetZ

iTrader: (11)

2003 5.3 iron block. Just took out the stock cam, don't have a lot of experience determining if bearings are bad or not. What do you guys think, its the one in the front?

PREDATOR-Z

Measure

blackLS1m6

iTrader: (14)

Gm cam bearings always have some copper showing. More than likely they are fine, but I would measure them to be safe. I'm a gm tech and I have yet to see an ls engine that wasn't showing copper on the cam bearings. They even look like that brand new out of the box. Gm also released information stating that it was normal too.

sic7camaro

iTrader: (21)

Thats good to know.but it still doesn't look normal.my motor cam bearing looks the same

wildcamaro

iTrader: (15)

Yea normally I would say yes it's toast but measure with dial bore gauge to check...measure 12/6, 3/9, and even 10/4& 8/2 just to be safe

Ethan[ws6]

iTrader: (13)

Normally I would say that this needs replaced. My schooling tells me that this needs replaced also. However, it seems that LS guys run bearings like this all the time and as per recommendation of this forum, I have done it myself on 4 different engines without issue.

Ws6kid.

Rather be safe than sorry I say.

silversweetZ

iTrader: (11)

Thanks for the reply's guys. I'll measure tonight and post up my results.

JaYZeig

iTrader: (11)

when i got my junkyard 6liter, i swapped cams, and my cam bearings looked like this, i decided to run em, and havent had any problems for over a year and 5k miles.

RezinTexas

+1 for measuring. up to 0.006" clearance is acceptable.

S10xGN

iTrader: (11)

The looser the cam bearing clearances, the lower your oil pressure will be when hot.

cranny

Every LS motor I've had apart, both low milage and high, have had copper showing. None have had any problems.

BlackScreaminMachine

iTrader: (17)

Agree to measure but like said seems like for LS1's the front bearings show that. What does the cam surface look like??

silversweetZ

iTrader: (11)

Can journals look great, no even a scratch anywhere on it!

LsxNotchy

mine look like that also.. havent started it up since i swapped the cam but i read that alot of people leave them so lets hope!!!

3rdCoastPowerSports

iTrader: (5)

looks more worn than the ones i have seen. U can run some pretty fucked up cam bearings and still have the thing stay together. Like S10GX said it make your oil pressure drop when the oil heats up. Your oil will also have stripper glitter in it. Im sure you could stick it back in and run it and be all good but you could also replace it and not worry again. Measure it and then make an informed decision

427

iTrader: (3)

Some GM engines have cam bearings installed that are undersize, then bored in position. These will have copper patches when the block has not been run. This seems to have stopped in recent years, but I have seen this a bunch in older engines. Sometimes if you change the bearings the cam will drag on the new bearings, this causes a nightmare....

Kurt

LS1MCSS

iTrader: (18)

This explains a couple of posts I have seen where guys got new cam bearings and then couldn't even get the new cam to go in the motor.

silversweetZ

iTrader: (11)

This is what the front of the cam looked like. Nice and clean!