An engine comprising a valve timing change mechanism capable of changing a timing for closing an air intake valve: wherein the valve timing change mechanism includes: a cam shaft rotatably interlocked with a crankshaft; a first cam and a second cam provided on the cam shaft and having different cam profiles; a first swing arm contacting the first cam so as to be rocked according to rotation of the first cam; a second swing arm contacting the second cam so as to be rocked according to rotation of the second cam; and a push rod connected to the first swing arm so as to cause the first swing arm and the air intake valve to cooperate with each other; characterized in that: the first swing arm is formed with a downwardly open piston hole, and the valve timing change mechanism further comprises: a receiving member attached to the second swing and extended to face a concave lower surface of the first swing arm so as to overlap the piston hole in the bottom view; and a hydraulic actuator vertically slidably attached in the piston hole of the first swing arm, so that when the hydraulic actuator slides downward and projects downward from the lower surface of the first swing arm so as to contact the receiving member, the first swing arm is parted from the first cam and the first swing arm is operated integrally with the second swing arm. wherein the valve timing change mechanism includes: a cam shaft rotatably interlocked with a crankshaft; a first cam and a second cam provided on the cam shaft and having different cam profiles; a first swing arm contacting the first cam so as to be rocked according to rotation of the first cam; a second swing arm contacting the second cam so as to be rocked according to rotation of the second cam; and a push rod connected to the first swing arm so as to cause the first swing arm and the air intake valve to cooperate with each other; characterized in that: the first swing arm is formed with a downwardly open piston hole, and the valve timing change mechanism further comprises: a receiving member attached to the second swing and extended to face a concave lower surface of the first swing arm so as to overlap the piston hole in the bottom view; and a hydraulic actuator vertically slidably attached in the piston hole of the first swing arm, so that when the hydraulic actuator slides downward and projects downward from the lower surface of the first swing arm so as to contact the receiving member, the first swing arm is parted from the first cam and the first swing arm is operated integrally with the second swing arm. a cam shaft rotatably interlocked with a crankshaft; a first cam and a second cam provided on the cam shaft and having different cam profiles; a first swing arm contacting the first cam so as to be rocked according to rotation of the first cam; a second swing arm contacting the second cam so as to be rocked according to rotation of the second cam; and a push rod connected to the first swing arm so as to cause the first swing arm and the air intake valve to cooperate with each other; characterized in that: the first swing arm is formed with a downwardly open piston hole, and the valve timing change mechanism further comprises: a receiving member attached to the second swing and extended to face a concave lower surface of the first swing arm so as to overlap the piston hole in the bottom view; and a hydraulic actuator vertically slidably attached in the piston hole of the first swing arm, so that when the hydraulic actuator slides downward and projects downward from the lower surface of the first swing arm so as to contact the receiving member, the first swing arm is parted from the first cam and the first swing arm is operated integrally with the second swing arm. the first swing arm is formed with a downwardly open piston hole, and the valve timing change mechanism further comprises: a receiving member attached to the second swing and extended to face a concave lower surface of the first swing arm so as to overlap the piston hole in the bottom view; and a hydraulic actuator vertically slidably attached in the piston hole of the first swing arm, so that when the hydraulic actuator slides downward and projects downward from the lower surface of the first swing arm so as to contact the receiving member, the first swing arm is parted from the first cam and the first swing arm is operated integrally with the second swing arm. a receiving member attached to the second swing and extended to face a concave lower surface of the first swing arm so as to overlap the piston hole in the bottom view; and a hydraulic actuator vertically slidably attached in the piston hole of the first swing arm, so that when the hydraulic actuator slides downward and projects downward from the lower surface of the first swing arm so as to contact the receiving member, the first swing arm is parted from the first cam and the first swing arm is operated integrally with the second swing arm.