Abstract: A dry-sump lubrication unit for an internal combustion engine for a vehicle. A crankshaft of the vehicle is disposed so as to be parallel with the direction of travel of the vehicle, and in a position offset from a center of the vehicle when viewed from the front or back of the vehicle. A transmission shaft is disposed on the other side thereof. An oil tank is disposed in a crankcase located substantially at the lower center of the crankcase when viewed from the front or back of the vehicle on the rear side with respect to the traveling direction, and/or in a space between the crankcase and a rear case cover. Oil pumps are disposed forwardly of the oil tank. An oil injection pipe extends from the oil tank toward the side surface thereof on the transmission side. The resulting configuration prevents variations in liquid surface of lubricating oil of the vehicle internal combustion engine due to shaking of the vehicle body, and makes it possible to downsize the entire power unit.

Abstract: An internal combustion engine with a hydraulically operated automatic transmission includes a crankcase that is divided on a plane perpendicular to a crankshaft and an outer face of the crankcase in a direction of the crankshaft is covered with a crankcase cover. A transmission gear ratio of the transmission is automatically changed over by control of oil pressures to remove a valve body for readily controlling oil pressures and for raising the accessibility of maintenance.