bmf5150

I have a 97 ls1 that supposedly has very low miles, pulled the cam and noticed that all the bearing are copper looking like a penny!are these warn out or do they all look like this??I checked my rod bearings and those look brand new!

bmf5150

Anyone?

Darkman

iTrader: (2)

I found a really old thread on this:

https://ls1tech.com/forums/generatio...per-color.html

And:
https://ls1tech.com/forums/generatio...ring-wear.html
https://ls1tech.com/forums/generatio...ings-shot.html

bmf5150

Thank you!! I did a search bit must not have used proper search term!!!

technicalninja

iTrader: (1)

I have second hand info about cam bearing wear regarding LS motors that is not in those old posts.
A buddy of mine became an Amsoil dealer and wanted to test their claims of increased oil change interval.
One of 2 cars he had tested was his wife's Pontiac GXP (20K miles). This car has the front wheel drive LS motor in it (think it's a 5.3l).

He sent oil samples to Blackstone three times. Ar 5,10 and 15 K.
The reports he received were VERY detailed.
The low mileage GXP showed lots of bearing materials (IE lead, copper). Blackstone included a note regarding commonly seeing this on this series of engine as the cam journals "migrate" a bit in the aluminum block through the heat cycle between cold and hot.
They went on to say this is normal, nothing to worry about, and that after enough mileage (heat cycles) it will dissapate.

I was very impressed with the Blackstone reports (and I am a persnickety exactly-right type of techy). His Amsoil was fine (more than 50% "good") at 5/10K and pretty worn out at 15K.

I wouldn't worry so much regarding the color. If the bearings lookv torn up, grooved, or "smushed-out" then I'd worry. I believe if you measure the bearing clearance it will be greater than the normal range but I'm not sure just how much clearance you can run before it's detrimental.

Some of those old threads seem to indicate the early cam bearings may not have had the babbit coating on them. I find this a bit hard to believe but it may be possible; I don't know for sure either way.

The Blackstone explanation seemed very believable to me. It also made a believer out of me regarding oil analysis value. It was extremely interesting as to what it could "show" you.

bmf5150

Awsome info!

Ethan[ws6]

iTrader: (13)

Bearings are shot. Replace them before putting everything back together.

bmf5150

Replace them??those post say the bearings came that copper color on the early motors?

Ethan[ws6]

iTrader: (13)

Can you post a picture? My cam bearings were not copper at all when I did my cam swap. Every time I have bought bearings (not just for LS1's) the bearings were silver in color new.

vettenuts

iTrader: (4)

LS1 cam bearing showing copper is very common. LS1 used oil analysis always show high copper content that would indicate the bearings were shot. This was a major concern back in the late nineties when people were first doing oil analysis on the LS1 but now it is realized that old standards don't seem to apply to this motor. There have been some who have said the cam bearings were line bored by the factory. A number of guys who replaced the cam bearings subsequently spun a bearing.

Unless they are a mess or you had oil pressure issues indicative of worn bearings, I would just put in the new cam.

bjamick

iTrader: (31)

I have a 216k mile lq4 sitting on my engine stand that has silver cam bearings. Also my 113k ls1 when I rebuilt it also had silver cam bearings. No copper here on either one, only thing I can guess is lack of maintenance on these particular engines. Maybe the particular filter being used isn't doing a good job in filtering the oil, or maybe just the oil being used.

Ethan[ws6]

iTrader: (13)

Yeah I don't care how common copper showing is, that doesn't mean it's good. If there is copper showing that means there is an obvious metal to metal contact. The bearings are wearing down..