Patent ID: 8156908

Claim:
An engine comprising: a valve configured to open and close a port formed in a cylinder head covered with a cylinder head cover; a drive cam mechanism operable in association with a crankshaft by a driving power transmission mechanism; a pivot cam mechanism including a pivot cam which is configured to be pivoted according to movement of the drive cam mechanism to cause the valve to open and close and is configured to change a pivot state to change a lift characteristic of the valve and a control shaft configured to be angularly displaced to change the pivot state of the pivot cam; and a driving source positioned at one end portion of the pivot cam mechanism such that the driving source is distant from the driving power transmission mechanism, the driving source being configured to angularly displace the control shaft to change the pivot state of the pivot cam; wherein the control shaft is positioned in an inner space defined by the cylinder head and the cylinder head cover; wherein the driving source is a motor including an output shaft for angularly displacing the control shaft and a motor casing from which the output shaft rotatably protrudes; wherein the output shaft is positioned in the inner space; and wherein the motor casing is positioned outside the inner space and mounted to an outer peripheral portion of the cylinder head.