Inliners International Forums General Discussion Engines How thick are standard main bearings...

For a Chevy 230? And rod bearings as well? I just rebuilt my motor and got very little oil pressure. I didn't go all out, and I thought my old bearings wern't marked as over-sized, I put standards back in. I guess I'm looking for advice before pulling it back out. The old bearings have these marks on them:
Mains-Clevite 77
9 88
MB3o10PL
or
M8046PL
s1

Rods-MICHIGAN 77
8 87
CB745P
E1

According to my mike, my old mains are 0.100.5 thick and the rods are 0.067 I understand that these are worn, but does that sound like standard or over-size?
I probably should have asked this question sooner.
Thanks

most bearings are marked as over sized Any Ones I ever had where. (.010,.020 so on) those numbers seem stock. hope this helps }[oooooo]

Dear Mr. Pritch;

Larry's probably right.

If It's not knocking your probably okay on the bearings.

Do the MFG dates; 9-88 & 8-87 correspond with the engine year and how low is the pressure??

John M....

Bearing wall thicknesswill tell you what came out of the engine,won't necessarly tell you the correct size to put in, wear etc.
The measurement you provide tell us that it WAS ASSEMBLED with .010 under bearings. Standard wall tickness for rod insert shell is .0621, you have .067; 005 more x 2 shells is .010 under. Main shell std. is .0955, do the math, .010 under. Should measure crank for the correct figures but it seems that you probbaly have at least .010 bearing clearance, hence the major factor in your low oil pressure.

Motorbone's answer seems like the the one I was afraid of. I had never seen bearings that were not marked as oversized, either, so I assumed they were standard. I guess I'll be pulling that motor back out. The oil pressure is seriously low. The idiot light goes out, but the gauge only shows about 20 psi at 2k rpm or so and goes no higher. Almost 0 at an idle. A lesson learned-measure everything-trust nothing.

Thanks,
Pritch