A valve gear for an engine includes camshaft supports, a camshaft, a rocker housing separate from the cam shaft supports, a rocker shaft, a first rocker arm, and a second rocker arm selectively connected to the first rocker arm by switch pins. The valve gear includes a second switch pin and a hydraulic piston that presses the switch pins, and first and second hydraulic supplies that apply an oil pressure to the pistons. The second switch pin is provided in a second rocker arm, and the hydraulic piston is provided in the rocker housing. The first hydraulic supply includes a first oil passage in the second rocker arm, the rocker shaft, and the rocker housing. The second hydraulic supply includes a second oil hole in the rocker housing.