oily bores

[JonE]

so any views on new pistons sizing generally in relation to Parazine's comment? I also have come to realise the enormous chasm in my knowledge of measurement and calibration. I've now (from a 10mm and 3mm drill base which I assumed might be correct-ish) calibrated my Japanese boxed caliper to about 99.2% accuracy. So as long as I keep using that for comparisons its ok, but there are all sort of places where its use becomes difficult.