braap

iTrader: (4)

I bought a '98 motor a while back to replace the one in my car (spun rod bearing) and decided to install a new cam before I put it into the car...here are what the cam bearings look like...



and the corresponding journal...



The grooves are around .005 - .010" deep and only on the lower half of the bearings. I'm assuming this was due to oil starvation?

braap

iTrader: (4)

What are the odds that the rod and main bearings are in similar shape? I guess there's only on way to find out...

TS6

iTrader: (41)

I think that is actually somewhat normal, do a search on cam bearings, I know alot of guys have copper colored cam bearings, I want to say its common on 98 motors?

braap

iTrader: (4)

Yes, the '98 bearings are supposed to be copper...it's the grooves that have worn into the cam journals that worry me...

su_maverick

iTrader: (9)

I always say better safe than sorry... better to spend the money now than have the engine sieze..

GuitsBoy

iTrader: (4)

The copper color is not the problem, as 98s had coppor colored cam bearings. The problem is the grooves or striations. Those look pretty severe. I would definately replace those bearings and the cam.

ShevrolayZ28

iTrader: (4)

I agree. It's common for cam bearings to be coated with a copper alloy, the copper we are seeing is not the issue IMO, it's the grooves that are a concern.

I think the cam and bearings should be replaced.

Maybe the grooves can be removed from the bearing but then there may be too much clearance.

Disclaimer: I'm not an engine builder. I could be wrong on this!

98_LS1

iTrader: (38)

I faced this same situation, copper colored bearings(which i guess are normal on 98's) and grooves on the lower halves of the bearings. The grooves were not that severe but i decided to change the cam bearings because i did not want to have to tear into it again or destroy my new cam. I bought a universal cam installation tool and popped the bearings in myself. By the way, you might want to check your rod and main bearings as well, mine had a spun rod bearing... engine runs great now.

MrDude_1

iTrader: (4)

that bearing is trashed...
if that was my motor, it would be coming out for atleast a cheapie rebuild....

777

iTrader: (21)

Everything about that cam looks bad. Even where the lifters roll there is wear; or so it appears. Looks like the pump went south and basically starved the entire engine of oil.

racecar

Looks like a high mile engine, or one that was run hard and put away still smokin.

braap

iTrader: (4)

I already picked up a new set of cam bearings...looks like I'll be replacing the main/rod bearings as well for peace of mind. Oh well, I guess it's a good thing I decided to slap a new cam in before I put it in the car. No telling when that sucker would have let loose

MrDude_1

iTrader: (4)

i would go the extra step and measure everything... i have a feeling your crank may look similar to how your cam does... and if thats the case, you need to get it turned and the matching bearings.....

bulletLS1

I had a 98 also, and the color is normal, the second cam bearing looks scrached too.
I agree with changing bearings, polishing crank, grind the bearing caps to 0.0015" clearance in a competent machine shop; they are too cheap (little expensive!) to trade for a blow up, while youre at it do yourself a BIG RELIEVE! buy ARP R*O*D*** B*O*L*T*S!!!!!!! the oem are made of chocolate, asparragus or some other simmilar material!!!!!!
also install NEW! oil pump, ported radiused, polished & shimmed, also install new chain, (cadillac variety) they are beefier than `98stuff, and a fraction of aftermarket price!
I suppose youre smart enough to assembly everything w/ ARP`s (at least new OEM crap!)

greetings from Guatemala!!!! (its raining cats&dogs :-/ )

braap

iTrader: (4)

Well, I finally got around to checking out the bottom end...looks like it's in similar shape as the cam, just not as severe.

Here are one of the rod bearings...


and the journal...


...main bearing (looks worse in person...couldn't get the camera to focus too well)



Looks like I'll be taking the crank to the local machine shop to get it polished.

67Firebird455

iTrader: (27)

EESH. That's tough news man, could've completely burnt up though, at least it's repairable. If the bearings were GONE, it would've ruind the crank, rods, or the main saddles, and turned them black. Get a new oil pump, new set of bearings, get her back on the road.

braap

iTrader: (4)

Here's something I found rather peculiar...it appears that this engine has two completely different pistons.




Three are like the one on the left...the other five are like the one on the right, even down to the burnt oil coating. It looks as though someone replaced them...surely it wouldn't have come from GM like this, no?

67Firebird455

iTrader: (27)

I surely wouldn't think so... that is really strange... Did you clean the one on the left or is that how you pulled it? Are you the original owner of the car?

67Firebird455

iTrader: (27)

The ones on the left look like speed pro cast or hypereutectics. The ones on the right look like the ones that come stock in the ls1. That is so strange, now you've got me wondering, what the heck happened?

braap

iTrader: (4)

Nope, didn't clean it at all. I bought the longblock a couple of months ago to replace the motor in my car which has a spun rod bearing. After I get this one back together I would've been better off pulling the stocker and repairing it ...oh well, at least I'll have a good spare.