how to select F225TXR main bearing

[jcbolos1]

how can i choose the part number for the main bearing of my engine. there are 3 choices in the part catalog.
1) UR#1
2) UR#2
3) UR#3

[boscoe99]

There is a table in the service manual that shows how to select the appropriate bearing colour.

[jcbolos1]

i dont have the service manual.
the color is for the connecting rod bearings. thanks

[boscoe99]

How can you be performing major maintenance without having a copy of the service manual? What about torque specifications, torque patterns, sealants, etc. that are all part of a major rebuild?

You need to get yourself a copy of the SM.

[jcbolos1]

thanks boscoe99 but this is just a request of my friend. i will tell him to buy service manual

[boscoe99]

Just to give you and your friend an idea as to how the SM works, see below.

Note that it says after selecting the bearing color or number, to test the clearance using plastigage. It then goes on to say that if the clearance is not right to use another bearing color or number. Unfortunately, there is no information given as to what other number or color to use to get the clearance within specifications. God only knows what the Japanese were thinking.

[jcbolos1]

i got the color of the connecting rod bearing (green).
can you gave me a clear copy of the chart for cylinder block mark (b) and crankshaft journal mark (a), i think this will help me finding the main bearing size, if it is UR#1, UR#2 or UR#3
thanks a lot boscoe99

[rodbolt17]

its actually dirt simple.
you look at the numbers stamped on the journal,this number represents the deviation from a nominal.
similar to the P,F and R numbers stamped on the gearcase.
the cylinder block numbers do the same thing, they are a measurement of what it actually got bored to rather than a dead target number.
so you look at the block number and the journal number and select a color.
there are no undersize bearings offered like automotive.