Patent ID: 7293497

Claim:
An internal combustion engine, comprising: at least one wall defining a bore; and a piston disposed in the bore and coupled to a piston rod to pivot about a pivot axis, the piston comprising a substantially circumferential outer surface having a head portion and a skirt portion below the head portion, at least a portion of the outer surface bearing against the wall in a thrust plane when the piston is substantially at operating temperature and subject to a thrust force, the portion of the thrust force borne by the skirt portion in the thrust plane is definable by a skirt force centroid, the skirt force centroid being positioned at an axial height substantially at the pivot axis or below the pivot axis, wherein the portion of the thrust force borne by the head portion is definable by a head force centroid, the head force centroid being substantially smaller in magnitude than the skirt force centroid.