Blow-by gas recirculation structure for engine

A blow-by gas recirculation structure for an engine adapted to recirculate a blow-by gas to an air intake system of the engine, the blow-by gas recirculation structure comprising:

• a gas-liquid separating member including a gas-liquid separating passage configured and arranged to separate oil from the blow-by gas;
• a cylinder head configured and arranged to rotatably support a camshaft, the cylinder head including a communication passage communicating with the air intake system;
• a support member configured and arranged to rotatably support the camshaft in the cylinder head;
• and
• a mounting bolt securely fastening the support member to the cylinder head with the mounting bolt threadedly engaging within the communication passage of the cylinder head, the mounting bolt having an axial through hole axially extending there-through and communicating with the gas-liquid separating passage so that the blow-by gas that has passed through the gas-liquid separating passage is recirculated from the axial through hole of the mounting bolt, through the communication passage, and into the air intake system.