Abstract: A positive crankcase ventilation (PCV) valve installation structure for installing a PCV valve of an engine on an engine body includes: a blow-by gas recirculation system that includes a ventilation hose that connects the engine body to an intake device introducing outside air into the engine body and that has a recirculation passage recirculating blow-by gas arising in the engine body to the intake device and an oil cooler device that exchanges heat between lubricating oil and a medium solution that is lower in temperature than the lubricating oil; and a cover that transfers heat of the oil cooler device to the PCV valve.

Abstract: A positive crankcase ventilation (PCV) valve installation structure for installing a PCV valve of an engine on an engine body includes: a blow-by gas recirculation system that includes a ventilation hose that connects the engine body to an intake device introducing outside air into the engine body and that has a recirculation passage recirculating blow-by gas arising in the engine body to the intake device and an oil cooler device that exchanges heat between lubricating oil and a medium solution that is lower in temperature than the lubricating oil; and a cover that transfers heat of the oil cooler device to the PCV valve.

Abstract: An engine lubrication system for a multi-cylinder engine, comprising: plurality of crank chambers that are partitioned by crankshaft bearing portions of the engine; pumps that take out oil from a lower portion of the engine; oil collection passages that are respectively provided for the crank chambers, a designated number of the oil collection passages being merged and connected to at least one of suction ports of the pumps; an oil storage section that temporarily stores the oil taken out from the lower portion of the engine; a lubrication part that supplies the oil in the oil storage section to a portion to be lubricated of the engine; and a pressure variation suppression section that is provided between the suction ports of the pumps and the designated number of the crank chambers to be merged, the pressure variation suppression section suppressing pressure variations in the crank chambers.

Abstract: An engine lubrication system for a multi-cylinder engine, comprising: plurality of crank chambers that are partitioned by crankshaft bearing portions of the engine; pumps that take out oil from a lower portion of the engine; oil collection passages that are respectively provided for the crank chambers, a designated number of the oil collection passages being merged and connected to at least one of suction ports of the pumps; an oil storage section that temporarily stores the oil taken out from the lower portion of the engine; a lubrication part that supplies the oil in the oil storage section to a portion to be lubricated of the engine; and a pressure variation suppression section that is provided between the suction ports of the pumps and the designated number of the crank chambers to be merged, the pressure variation suppression section suppressing pressure variations in the crank chambers.

Abstract: A camshaft drive arrangement for an internal combustion engine wherein the drive includes first and second intermediate shafts journaled directly within the cylinder block. The first intermediate shaft is driven directly to the crankshaft and the second intermediate shaft is driven from the first intermediate shaft by a flexible transmitter drive. The second intermediate shaft drives a camshaft journaled in the cylinder head by a second flexible transmitter drive.

Abstract: A lightweight high-strength cylinder block that is configured so as to provide an enlargement at one end thereof that defines a bell housing. The enlargement is provided with cavities, however, so as to lighten the weight of the cylinder block without substantially reducing its strength. At least one of these cavities can provide for communication of oil return and/or crankcase ventilating gases and also may function as a thermostat housing. An embodiment wherein the cylinder block extends below the crank shaft axis to form the upper portion of the crankcase is also disclosed.