Conrod bearings

[Themadmob]

Hi All .. I am on the process of overhauling my 1960 Series 2 engine and the conrod bearings are shot .. lots of numbers .. but if I am reading it correctly .. are the bearings .10 Oversize ???... Also any idea what caused the one bearing to smudge more than the others as well as have burrs on the side ? Thanks106118106119106120

[schuy1]

I think you are reading that right. .010 The burring? Rough thought is its been hammering from wear. What does the crank look like?
Cheers Scott

[Themadmob]

I am About to pull the crank out ... I am going to strip the motor entirely as it seems the safer option .. it looks like the bearings and pistons are 010 oversize .. do I replace everything at 010 or do everything to 020 ???

[schuy1]

That will depend on if the crank needs to be reground at all. If it has scouring on the surfaces yes it is best to. Having said that I have fine emery paper journals and installed new shells and its worked just fine. The thing to remember with these motors are that they are not a race motor running super critical clearances and pulling 8500 rpm :D I have pulled them apart and there is no bearing metal left! and yet for all intents they were chortling along happy with 30-40psi oil. Mind you idle psi was a bit different!
Cheers Scott

[mick88]

The whole crank will have had a grind, so your new bearings (both big end and mains) will need to be ten thou under, unless of course it needs another grind.
Measure the crank journals to see if they are in or near spec.
Hard to tell from the pic, but have they been hot due to oil deficiency?

Cheers and good luck.
Mick.

[vnx205]

Strictly speaking the pistons are probably oversize and as Mick88 has hinted the bearings are more correctly referred to as undersize.

However, we knew what you meant. :)

[Themadmob]

Thanks guys I will post pics soon if crank and bearings