Morris Minor Owners Club

I am making this reading 0.001'' over the standard 1275cc bore measurement. yes/no?

I think 1 thou is slightly less than a calibrated knats whotsit

Thanks, maybe someone will confirm that as well.

Hopefully

Looks like that's reading "2815" ?? But what the scale is I have no idea!
Standard bore is 2.780"
So - if there is a 2.500 spacer in front of the vernier - then yes, that reading would make sense as 2.500 + 0.2815 = 2.7815 ie 1.5 thou over standard bore ?

There is 2'' in front so you are saying 2.2815? Which is 1 1/2 thou more than standard 1275 bore?

If only 2" in front - then that's only 2.2815 - which is far too small for any A series! It must be 2.500 " in front - surely ?

Sounds right, as long as your mic has been reliably calibrated! If you are doubting your bore for wear, try a check at the bottom of the bore, which is likely to be correct size. I would say the top above the wear line, but it may have been glazebusted. Glazebusters don't usually get down to the bottom of the bore, or only half-heartedly.

Sorry, yes you are quite right 2.5, I have posted because I would have expected more wear in the bore than 1-1 1/2 thou, I am surprised and started to doubt the reading! thanks.

Excellent! Yes - I recently opened up a 1275 that had been very badly treated - the 'oil' was thinner than water and the sump had a thick (well over 1 inch) layer of black sludge in the base. Yet the bores and the crank bearings are perfect!! Amazing.

I have checked at the bottom of the bore and it may be slightly tighter, but does confirm the mic reading ok. I reckon I can just glaze bust and fit new rings, if available!

Provided the ring grooves and the 'lands' in the pistons are ok - then yes! I will just be reusing the rings that came with my engine.