conrod and main bearing sizes

[Pav]

how do i find out the size for an engine's main bearings and conrod bearings?
i checked and it says +10 +20 +30 +40 and +50

[vn calais manual]

workshop manuals, i think the +10 ect i assume your refering to oversize bearings in thou?

[Pav]

yep thats what im refering to, so what does it mean, how would i know what oversize I would require, just simply check workshop manual? orr? (this is for a VN 5L btw)

[Blown V6 Hatch]

You can't check the bearing size unless the motor is in pieces. When you pull the bearing shells out, on the back will be a part number, then there will be a number directly below it i.e 010, 020 etc. etc. If there is no marking, it's safe to say it's standard, if there is a marking then thats what they are oversize....However, generally when you rebuild an engine the crank will more than likely need a grind anyway. If thats the case the machine shop that does the crank will inform you as to what bearings you need (they generally write it on the crank counterweight).

[Pav]

Thanks dude, that was what i was after. Although this is just a bandaid fix for a bad bottom-end knock, do you reckon it might still knock if the crank is left as is, and only the bearings replaced?

[vn calais manual]

id say so, yes.

[Blown V6 Hatch]

If you just wack a new set of bearings in it, chances are it will do it again (depending on the cause ofcoarse). If it was me, i would get the crank ground and the rods resized.