VALVE TIMING FOR FOUR STROKE INTERNAL COMBUSTION ENGINES

摘要

A method of controlling a four stroke internal combustion engine having at least one combustion chamber, the or each combustion chamber having at least one exhaust valve, the method including varying the timing of the closure of the or each exhaust valve with respect to the crank angle of the engine by advancing the exhaust valve closure at least under certain engine conditions in response to an increased engine load, and/or delaying the exhaust valve closure at least under certain conditions in response to a decreased engine load.