INTERNAL COMBUSTION ENGINE AND TRANSPORTATION DEVICE

An internal combustion engine (100) includes a piston (40) formed of an aluminum alloy, the piston including a piston head (43) and a piston skirt (44) extending from an outer circumferential portion of the piston head; and a cylinder block (10) formed of an aluminum alloy, the cylinder block including a cylinder wall (12) including a sliding surface (12a), along which the piston is slidable. The aluminum alloy is exposed to the sliding surface of the cylinder wall. The piston skirt includes a skirt substrate (b1) formed of an aluminum alloy, the skirt substrate including a plurality of streak grooves (sg) formed in an outer circumferential surface thereof, the piston skirt further including a resin layer (rl) formed on at least a part of the outer circumferential surface of the skirt substrate. The outer circumferential surface of the skirt substrate has a ten-point average surface roughness RzJIS of 20 µm or larger.