After re-bore the bottom of the cylinders are quite sharp. Is it common to relieve the bottom of the cylinders to prevent the piston from being scraped by the bottom of the cylinder? Have 6 thou clearance but piston can still tip slightly at BDC
I searched quite a bit and found a machinist site. They say they smooth the bottom of the bores off to reduce the risk of the sharp edge scuffing the piston. Say it has to be as smooth as a baby's A.. they us a small disc of some sort and then fine paper to smooth the sharp edge. Makes sense the bottom of the piston goes below the bottom of the cylinder at BDC if the piston tips/rocks even slightly it could catch the sharp edge.