Q6. A completely new unit comprising piston, rings, liners, cylinder head and valves was fitted to a six-cylinder single-acting four-stroke diesel generator. Before installing the clearance and sizes were checked and considered satisfactory. During a trial run the running characteristics were abnormal so the generator was stopped. On examination, it was seen that the new piston had badly scored and drubbed the liner and had indication of seizure in the upper part of the liner. Give your reasoned comments for this failure.