zaquhree

Hi all. Some may remember me from my terrible experience with my current Z06 with a lifter failure causing me to find worn bearings due to metal in my oil. I had a respectable machine shop rebuild my 427 with Darton sleeves, stock crank refreshed, had my rods coated by Calico, and Diamond custom dished forged pistons. All of my other cars have outperformed my expectations and exceeded my expectations for durability, this car has really shaken my confidence so I'm not sure what to do here. My builder said they measured out and he didn't need to replace them. His work speaks for itself so I trust his capabilities but I don't trust my luck. Posted this somewhere else but deleted it because I just want some level headed advice. I'm really scared of something going wrong and losing the last ounce of motivation I have to keep going on this...thanks for the help along the way I just want to drive my car. Going a little crazy after owning it since August and driving it one day before having to pull the motor.

MAD Matt

Do it nice or do it twice.....replace them !

itsonlyairandfuel

I can't believe anyone would say that, if they had to stand behind their work. Replace them.

ss2z06

It’s your motor, your money, and your peace of mind. Replace them and don’t look back.

Navy Blue 210

Agreed!

zaquhree

I'd rather have the peace of mind that's for sure. Does the rotating assembly need to be taken out? I was reading that GM line hones the bearings for fitment

clubracer23

Trust your engine builder, you said you do. If you have the cam bearings replaced and there is an issue who’s to blame? My cam bearings looked similar to yours on my track car the last time I had it rebuilt and I haven’t had any problems. Also, I have had a cam bearing spin shortly after it was replaced so my opinion is biased.

73DBG

Bro! Change all the damn bearings....seriously you want a a relatively cheap part like that ruining your fresh built motor? My engine builder probably would have stoped building my **** if I said don’t change the bearings, I know you didn’t say that it was the shop. I’m just saying it was just a given that on my bottom end refresh all that’s was getting new coated bearings. Did you get some Johnson 2110’s? Or are your staying factory lifter? I 100% am no where remotely close to be an expert or an engine builder, but this advice would alarm the **** out of me😳 I was so paranoid about ******* up my fresh rebuild I replaced everything on the car that oil flows through with new ****. Only thing I didn’t get new was the dry sump tank but I did have it sonic cleaned, there was no metal hiding in there but it gave me piece of mind. Good luck 🍀 I’m sending some your way!!! 🇺🇸

sccaGT1racer

They can be done without disassembly of the short block. I can tell you that you may have to do some work on the new bearings to get the cam to turn properly. Its pretty common with the ls engines.

RobGOV-DCZ

dmaxx3500

how hard is it to put cam bearings in?

unless GM changed things?

those look like ''JUNK''

RobGOV-DCZ

It believe is normal for cam bearings to be showing copper in some brand new LS engines from the factory. If builder said they were in spec i wouldn't worry at all.

zaquhree

I trust my engine builder. I will update this thread with my success or failure of any kind, cam is going in today to put these thoughts behind me. After a lot of reading and talking with friends it seems this is normal wear & I run a risk swapping cam bearings since GM line hones them after installation for clearances

redbird555

If it was a normal sbc I’d be concerned but those bearings look fine for an ls. Replacing bearings at this point may open up more problems than they would solve. Replace the bearings and you might get metal particles into the shortblock and they may need to be line honed

MickVette

Since you had metal in your oil I would think the cam bearings should be pulled and make sure no debris is trapped where the oil is fed to the bearing if there is a lip that could catch debris.

zaquhree

Yes sir I am going to circle back but I'm 99% sure he said he removed the bearings before cleaning my block to measure and so they didn't get damaged by the solvent he used

Dan_the_C5_Man

Those bearings look like every other set that has been run for any significant amount of time in an LS engine.

All the folks saying "OMG, those look horrible!", well, yours look the same..

zaquhree

Lol yeah that's what I learned. Figured my builder built the engine for the fastest stick shift Vette and one of the fastest SBE LS7 cars in the US so I trust his judgement just wanted some opinions so thanks everyone Motor should be back together next week and then dropping it in ASAP.

Sébast19X

As per experience it's not normal. It's fairly common for the Aluminum block to shift a bit during machining process from factory. The key of every built are to measure. Cam bearing clearance of my LS7 block was off from factory. After my sleeving process I measured it at 0.003'' vertical oil clearance and as tight as 0.001'' horizontal clearance on the number 2 & number 3 cam bearing (same as before sleeving process and I forgot to mention to the machine shop during the process my error BTW). Because no machine shop with a cam line hone/bore are avalaible in my area, I have instead machined down the cam journal by 0.002''. That have gived me 0.005'' vertical and 0.003'' horizontal oil clearance. And that way (not the perfect way) I respect the specs of min. cam journal from the factory specs. I also respect the clevitte cam bearing specs for min and max oil clearance. Always replace worn cam bearing like that and measure. This is the key. Also LS7 block came from factory with two type of cam bearing width. E.g.: Dura Bond CHP23 are narrow and CHP25 are wider if my memory serve me well (As per the pictures you seem to have the narrow one). I don't remember Clevitte part number sorry. Also remember the LS aluminum block shift a bit at operating temp.... Better have bigger cam bearing clearance than tighter one ... With this clearance my oil pressure are perfectly fine and hight at idle hot on regular 5w30 if someone asking.

I hope this help

Sebastien