Piston ring scuffing

[Dave Mann]

Further inspection of the engine reveals the top ring gap has opened from 0.006” to o.050” and the top ring vertical rattle in it's groove of 0.015” hence the oil consumption of a pint in 50 miles while the cylinder bores have little wear with some of the machining marks being visible after 22300 miles. I suspect the materials of piston and rings may be wanting. This is the last engine to be rebuilt whilst one car has an engine rebuilt in 1985 has done 53300 miles and consumes a pint of oil in 700 miles.