Main Bearing Chart Interpreting

[Tim_zenki]

Hey SAU,

Im not sure if you would classify this as general maintenance but i'm currently trying to use a micrometer and check the condition of the oem main bearings on my r32 rb26 and im completely mind f**ked by this chart lol.

Heres the information from the 3 sources it asks for..

Bearing Housings No. Bore Grade No.

No.1 3 2

No.2 3 2

No.3 3 2

No.4 2 2

No.5 2 2

No.6 2 2

No.7 1

Upper Journal Grade No.

No.1-7 1212111

No.1-6 111101

and heres the chart itself from engine manual for r32

[Tim_zenki]

and for future conversational sake for others and myself, here same chart but numbered.

[Tim_zenki]

and that chart i got from the r32 engine manual but its different from the chart ive found in the r32 full factory service manual...odd.

[Duncan]

I'd be surprised if you get relevant experience on this; once a bottom end is apart pretty much anyone is going to machine it and use new bearings (of a single grade within a size). Some top end race builds might try and blueprint by choosing the best bearing from a set for each journal but frankly the more important part is consistency of the machining.

[Tim_zenki]

yeah i wasnt going to reuse my old ones, just wanted to learn how to measure them and read chart etc.