Valve timing control system for engine

摘要

A valve timing control system for varying a valve timing determines whether an engine operating condition falls within a specific valve timing range established for a specific valve timing or a standard valve timing range, other than the specific valve timing range, established for a standard valve timing. A valve timing device is activated so as to change a valve timing to the standard valve timing when the engine operates in the standard valve timing range. The valve timing device is also deactivated so as to change a valve timing to the specific valve timing when the engine operates in the specific valve timing range.