This might be the case
As a matter of course I would get this particular cylinder (what I think they call) 'owned out or honned out' can't remember which but this scores the cylinder surface very finely ready to accept a new piston and rings as if it was a new engine block. Otherwise the new piston will be replaced in to the cylinder with all the old deposits of the previous piston. This can lead to burning oil due to seapage in that cylinder. A reputable engine builder or machiner will do this. After this you must treat the engine as if it is new and put running in oil infor about 500 miles, drain it and hopefully it should be right as rain. I speak from experience but only on an old mini engine, I can't see that this method would changed, but please correct me if I am wrong. This is not a method of reboring, just a way a scratching the surface to get rid of burnt on oil and carbon build up at the block head
