An internal combustion engine (100) includes a piston (40) formed of an aluminum alloy; and a cylinder block (10) including a cylinder wall 12 including a sliding surface (12a), along which the piston is slidable. The cylinder block is formed of an aluminu...

A piston is provided in which the amount of uncombusted and discharged air-fuel mixture is small, and agglutination of a piston ring due to heat is prevented. In a piston 2 in which plural peripheral grooves in which piston rings are provided are formed in...