Engine and Straddle-Type Vehicle Including the Engine

An engine comprising:

• a crankcase;
• a crankshaft accommodated in the crankshaft;
• a connecting rod connected to the crankshaft;
• a piston connected to a tip end portion of the connecting rod;
• a piston ring attached to an outer peripheral surface of the connecting rod;
• a body cylinder connected to the crankcase, and including a cylinder section inside of which the piston is displaced;
• a head cylinder connected to a tip end portion of the body cylinder;
• and
• a cylinder fixing bolt having one end portion extending toward the head cylinder and an other end portion extending toward the crankcase, the cylinder fixing bolt connecting the head cylinder, the body cylinder and the crankcase to one another,
• wherein the cylinder section includes:
• a lower section located within the crankcase;
• and
• an upper section located at a higher position than a position of the crankcase, and wherein
• the piston ring abuts on the lower section when the piston is located at a bottom dead center.