Z284U2TRY

iTrader: (5)

I took this picture of the main cap out of a 454 lsx engine.
This is a Clevite main bearing.
I have not inspected the rest of the engine yet.


What would cause the leading edge of the bearing to loose material like that?
The crank is in near perfect condition.

Gunslinger09

Crank end play wasn't right.

Z284U2TRY

iTrader: (5)

Woould crank end play just damage the edge of the bearing like that?
I though maybe a piece of trash or something had damaged the bearing.
Going to pull the rest today and look at them.

Steve - Race Eng

iTrader: (1)

Either the main bearing bore is tapered or the crank is tapered. You need to check both to be sure.

If the block is the problem (most likely) get it align honed or align bored to correct the problem. If the main bearing journal is tapered or out of spec. (less likely) the crank will need to be ground.

Steve

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Quick Carl

You didn't say, but is it #4 with the wear toward the front of the engine or sometimes #2 with the wear toward the rear? #1 with the wear toward the front if you are running a blower or something off the front of the engine that abnormally loads the snout.
Check the housing bore and journal for taper like Steve said, but sometimes this still happens even if they are straight due to crank flex especially on a 4.125" stroke.
Not much you can do except give it a little more clearance to flex without upgrading the crank.

Z284U2TRY

iTrader: (5)

This is cap #3.
The engine is N/a around 10000 miles on it.
The engine started its life as a 454 from scroogin-dickey.

The cam bearing seems to have similiar wear on it.
The block is off to the machine shop for inspection.

Quick Carl

GM LS? #3 should be a flanged thrust bearing ?

Z284U2TRY

iTrader: (5)

My mistake #2