How do these bearings look?
 

I've never seen worn bearings before, so I have nothing to compare to.

https://www.dropbox.com/sc/rzukyitdyzysozg/ZecVAPX7SC

They seem to be within spec, obviously some scoring. Just to put things in perspective...I'm over 50 years old an this vehicle will likely only get 6k miles per year. (currently has 93k) Will tow a 2500lb boat/trailer maybe a dozen times a year for 45 miles round trip.

My thought is "let 'em ride" but like I said, I've got no experience here.

A bit of background...the oil pickup screen was so clogged, I don't know how any oil got through. Not sure if the previous owner (I've only had for a few weeks now) never changed oil or put some sort of stop leak in, but everything was pretty gunked up and the rocker/pivots were very scored.

https://www.dropbox.com/sc/u9l0yl13jvgwnmq/ExV9fpjx-t

...the oil pickup screen was so clogged, I don't know how any oil got through


Your answer right there ^.When in doubt change 'em out.You already have it 1/2 torn apart.If I had a engine I knew wasn't getting oil I would replace the bearings.

I'd suggest several very frequent oil/filter changes. Shine a flashlight in the oil fill hole regularly to see how things r cleaning up.

Barring something odd it's gonna be the rods, or a piston/ring that finishes an engine. For the price, since you are there I'd definitely install new inserts. (I've done it simply because an engine was out, a couple of times). They are pretty cheap. What is stamped on the back? Std? 10, 20?

I'm curious, did you look at the pictures and feel they are worn/scored to the point of needing it despite being in spec according to the plati-gauge or just making the general statement knowing oil was a-fowl? I'm not saying you are wrong, just trying to know where my advice is coming from.

Well, I'm assuming you are asking about the back of the bearing not the cap.

On one side I see A-02, on the other I see F-85 and directly below that, 05-01

Oh, the bearing insert it's self. If you do opt to change them you will need a match there. If the crank has been ground, say .010 under, there will be a 10 on the back of the insert. (they pop right out, just be cirtan there is nothing under it when you put it back). I think I saw them on rockauto for $20. I'd happily pay twice that to pick them up at my local Napa.

Please see my post above, I've got nothing resembling standard or std or 10 or .010 or....

On one side of the rear of the bearing insert I see A-02, (maybe position 2 which it is) on the other, with the tab, I see F-85 and directly below that, 05-01 (maybe date code, my xj is a 2001). Cap has a large 2, under that something i don't recognize and under that a 7. I added a couple pics to the main bearings picture set showing these stamps

price looks like about $75 for Sealed Power set...I'm just 80 dollaring myself to death :blink:

All else fails find a paper bearing cataloge and check the tolerances .

Bearings in the photos look OK. No copper showing and only maybe .0005" wear. Some advice if you do decide to replace them is to mic the journals (all of them!) with a good set of callipers. The factory did not always stamp the size on the inserts and sometimes they use NON-STANDARD size inserts! It is common for the factory to screw up a crank journal and then grind it down and fit a non-standard insert.
Run Rotella or Walmart Super-tech 15-40 and that engine will magically clean itself up after 4 or 5 routine oil changes.

Seriously? Then how the heck would they know which insert they were installing? I doubt they went with trial and error. An interesting idea, but I'd bet an oversize/undersize would be stamped.

They used a letter code stamped on the block
P= one or more rod bearings at .010
M= all mains at .010
PM= all mains and one or more rod at .010

The inserts themselves were coded

just curious, does anyone know the accepted clearance on rod and main bearings? .051 is an awful lot of room when regarding bearings.

i'd figure out the clearances first, then go from there. i'm familiar with sbc motors being .010 - .020, the tighter the better. pretty sure lsx are .0008 - .0025

2000 FSM says
.0010-.0025 mains clearance
.0015-.0065 mains end play
.001-.003 rods clearance (.0015-.0020 preferred)
.010-.019 rods side play

fwiw the bearing shown here is the main

The one I measured (#2) appears to be in the .0019 arena, well within desired spec

I guess I may as well check a random rod for clearance while I'm down here...