OIL RETURN DEVICE FOR ENGINE

摘要

PROBLEM TO BE SOLVED: To reduce the deterioration of oil which flows in an oil passage by receiving heat from an exhaust passage. SOLUTION: Exhaust ports 5 are arranged in a cylinder head 1, and valve systems are formed on an upper side of the cylinder head 1. Push rod holes 11 for communicating the valve systems and crank chambers with each other are arranged in the cylinder head 1. Oil forcibly fed to the valve system chamber is returned to the crank chamber sides through the push rod holes 11. Banks 13 are arranged on upper edges of the push rod holes 11 so as to block that oil which flows toward the push rod holes 11 flows from the exhaust port 5 sides toward the push rod holes 11.