ok, I have a spare block and it turns out it's already rebored.
pistons are likewise marked :
wierd thing is they also measure 86.45 at their widest part (bottom)
just what are the standard overbore increments for pistons, and can anyone tell me exactly what I measurements I should be getting going on the above piston markings ?
I thought piston > bore clearance was 1 thou/0.25mm - yet from the above I'm now confused, which doesn't take much admittedly
It seems fairly likely that the crank I have has been reground also (assuming bottom end was rebuilt fully) - so what should I look for on the shells - I had a quick look at a main one and saw 0.25 - I assume this is the oversize ?.
Also, what it the maximum oversize for the shells as the crank needs another regrind judging by a couple score marks.