•  The oil jet valves are installed in the cylinder block. The oil jet valve nozzles are installed pointed toward the back surface of each piston.

•  The oil jet valves are designed to maintain optimum oil pressure in the engine by controlling the oil injection according to the oil pressure applied to the check ball in the oil jet valves.

•  Oil pressure applied to the check-ball in the oil jet valve opens and closes the oil passage‐way to the nozzle and controls oil injection starting and stopping.

•  Oil pressure greater than the specified value applied to the check-ball in the oil jet valve opens the oil passage to the spring-pressed nozzle, starting injection. Conversely, oil pressure less than the specified value applied to the check-ball blocks the oil passage by spring force, stopping injection.