Patent ID: 7438037

Claim:
An internal combustion engine comprising: a cylinder block having one or more cylinders; a cylinder liner with a tubular shape, disposed inside said cylinder; a piston reciprocating inside said cylinder liner and having a top land portion formed of an outer periphery of the piston sandwiched between a piston head and an uppermost ring groove; and a liner installation ring forming a circular step portion inside the cylinder, and disposed in said cylinder block or said cylinder liner in such a manner that a bottom face of the liner installation ring faces to an uppermost portion of said cylinder liner, the circular step portion protruding to an inner periphery of said cylinder liner, wherein: said liner installation ring is disposed at a position in accordance with a top end position of said top land portion when said piston reaches a top dead center; a circular projection, in a tapered shape, inclining downwards to the inside of the cylinder from a crosspoint of the bottom face of said liner attachment ring and the inner periphery of said cylinder liner, is formed on the bottom face of said liner installation ring along an inner peripheral end thereof; an angle that a tapered surface of said projection forms with the inner periphery of said cylinder liner is in a range of 45 degrees to 60 degrees; and said liner installation ring is set to protrude from the inner periphery of said cylinder liner in an inward direction at a length of 0.05 mm or more to 0.5 mm or less.