nate99

Not mine, but one from the rear main of an SBC out of an old truck that was leaking prior to tear down. I know some folks here have seen their fair share of bad bearings.

I'm guessing toast, but that's just a mostly uneducated guess.

Mark Riles

Yep, bearing is no good. Crank needs to be turned or replaced. Good news is the bearing never spun.

mrvette

You may get lucky on the crank, drag a razor blade across the surface at 90* to the crank metal, from side to side, see if it catches, if it does, you need look really close...

69 Chevy

How bad? Normal wear depending on how many hundred of thousands of miles is on the odometer. I wouldn't reuse bearing shells that look that worn in my Vette. But a low-revving truck engine might still give a lot of serviceable miles in that condition. You'd be surprised how many vehicles' bearings look like that...out of sight, out of mind.

anips

need to mic the journals might get by with a micro polish on the crank.

nate99

It's definitely high mileage, thanks all for the replies.

Indiancreek

There has been some debris going through the oiling system. Personally I think it's time to bake the block and do a rebuild. The lines are from the debris and shows crank bearing contact so I'd say clearances have grown to the point of pressure drop.
Not going to engage in the argument about to begin with regard to your rebuild.

nate99

Nor am I. Thanks.

Ironcross

In a word, it`s DEAD!

mikes wont help it as its definitely out of round and your dealing with only a couple of .000.........

jordan89

time for a rebuild.

Indiancreek

Not with you, but if you ask about a rebuild on here, you'll see a rehash of the samething just a couple weeks ago. You'll see recomendations from working within your budget to the limit. That's where it turns from a discussion to an argument.
Look up the thread My engine just blew or one on what piston do you recommend and you'll see what I mean.
Anyway, so far everybodies on the mark, to much wear causing pressure drop. At least it's even wear pretty much. Nothing spun from the pic.

Steve2147

What do you want to do with it? Why did you take it apart?

Yes, the bearing is finished and yes, there's some scoring on the crank, but if all you wanted was for it to run for another 30 thousand you can probably just replace all the bearings and button it up. It won't run any better other than the oil pressure will be a bit better, might be a bit quieter, may reduce oil consumption by the rods not throwing as much oil on the cyl walls, but all in all it's a well worn engine that will continue to run for some time.

If, however, you pulled the main to assess the general condition of things, the motor is tired and will take a major overhaul to bring it to the like new performance.

Steve g

nate99

The engine is not mine. I think they were going for a rear main seal replacement only, but decided to check out the bearings while they were in there.

Sounds like a roll of the dice with anything but an overhaul.

Thanks again.

smearig

It's a 17 y/o kid's first truck to get him back and forth to a job at a carwash until the end of the summer when he's enlisting in the Army.

It had a terrible leak (pools 6"-12" in diameter) from the valve cover gaskets, oil pan and rear main seal. We replaced all that and now I'm trying to make sure this thing can last a few months. I suppose it would be an option to drop the crank and slap in some new bearings for $30, but that's getting to the ragged edge of my engine experience.

Good info, thanks.

63mako

Throw a set of standard main and rod bearings in it (if they are originals) and button it up. Might get him through the summer, Might run another 50,000, Might blow up in 50 miles or not even crank. Pretty cheap and not a lot of work since it is already opened up. JMHO

Steve2147

You may have a hard time getting the rear main to stop leaking with the bearing that bad. It'll be flowing a lot of oil out that main.

You don't drop the crank to replace the bearings. You roll them in. Small amount of skill req'd. Need a torque wrench and know how to use it. You've already done the hardest part of the job.

Steve g

bpassmore

with Steve 100%, At this point in the engine life cycle and the limited usage, it is the only economical path. Roll in the new bearings, but might think of a new oil pump. Those items are cheap.

BlackC3vette

Good advice

Steve2147

In the name of instilling confidence rather than fear and uncertainty, my engine or yours might blow up in 50 miles. This engine might have blown up in 50 miles had he not taken it apart. The chances of it blowing up in 50 miles are immensely reduced with new bearings. If it does, it won't likely be due to a spun bearing.

Done with just the smallest amount of care, all that the job warrants, can't see how it might not even crank. Not something someone should lose any sleep over.

Read the back of the bearings to determine if standard or under. There is a tool you stick into the crank oil passage to push the shell out as you rotate the crank, but I just use a cut off nail with a large enough head that it won't go into the oil hole and thinner than the shell thickness.Clean everything up and oil only the bearing surface side of the bearings. Don't knick the crank.

Plastigage ($2) at install. If you're under .003 and over .0005 (won't be)you're fine. If you are approaching .003 you might consider a high volume pump to compensate. Pretty much same price as reg volume. Loosen all mains, but only do one at a time. Do each rod one at a time. Ensure caps go on oriented as you took them off. Locking tabs on the bearings will be on the same side when installed correctly. Torque to spec.

Steve g

Tim H

Polish the crank add new bearings and an oil pump and button it up.