Valve for an overhead cam engine and an overhead cam engine assembly

An overhead cam engine assembly comprising:

• an internal combustion engine;
• a plurality of valves configured to be mounted in the engine, each valve including:
• a cylindrical valve sleeve including:
• a top portion defining an annular shoulder, and
• a bottom portion defining a plurality of ports configured to convey a flow of fuel and gases into or out of an internal combustion chamber of the engine,
• a valve cylinder disposed in said valve sleeve, said valve cylinder including a cylindrical body and a top cap, said top cap defining:
• a contact surface, and
• an annular projection extending radially outwardly of said cylindrical body, and
• a valve spring disposed about said cylindrical body so as to be pressed between said annular projection of said valve cylinder and said annular shoulder of said valve sleeve, said valve spring configured to:
• bias said valve cylinder partially out of said valve sleeve so as to unblock said plurality of ports and open the valve, and
• compress as said valve cylinder is axially displaced into said valve sleeve so as to block said plurality of ports and close the valve;
• and
• a camshaft configured to be rotatably mounted in the engine, said camshaft including a shaft portion and a plurality of cam lobes projecting from said shaft portion, each cam lobe configured to continuously engage said contact surface of a respective valve of said plurality of valves, each cam lobe including:
• a cam nose configured to axially displace said valve cylinder into said valve sleeve against a biasing force of said valve spring so as to block said plurality of ports of the respective valve, and
• a cam flank configured to enable said valve spring to axially displace said valve cylinder partially out of said valve sleeve so as to unblock said plurality of ports of the respective valve.