Patent ID: 7637236

Claim:
An overhead-cam internal combustion engine, comprising: a crankcase forming a crank chamber for disposing a crankshaft therein; a camshaft disposed in a cam chamber which is situated above said crank chamber; a cylinder block having at least one cylinder formed therein defining a cylinder axis; a cylinder head fastened to said crankcase or to said cylinder block, said cylinder head having intake and exhaust valves reciprocally mounted therein; a head bolt extending between said cylinder head and said crankcase or said cylinder block, a cylinder head cover connected to said cylinder head; and a valve actuating mechanism comprising a camshaft for selectively operating said intake and exhaust valves in said cylinder head; said valve actuating mechanism being lubricated with lubricating oil in a cam chamber defined between said cylinder head and said cylinder head cover, wherein said cylinder head is provided with an outer bolt-receiving hole in which said head bolt is inserted, and which is situated outside of said cam chamber, and said cylinder head is further provided with an oil discharge passage having an inlet opening into said cam chamber, and an outlet opening into said outer bolt-receiving hole.