A novel cylinder head arrangement for an in-line four cylinder or eight cylinder engine. A modified arrangement allows additional space for installation of wider rocker arm assemblies used for variable valve lift (VVL), cylinder deactivation (CDA) and other types of variable valve actuation (VVA). In one embodiment, cam towers adjacent the end two cylinders are not used. At least one end support is used, which may be an outboard bearing on a camshaft for each end. The wider rocker assemblies may then be installed. In another embodiment, cam towers adjacent the inner two cylinders are eliminated and a single camshaft support piece with a support bearing is installed between the inner cylinders to provide support for the camshafts. The wider rocker assemblies may then be installed on at least one of the middle cylinders. A novel oil control valve operates latches in switching rocker arm assemblies.

An engine block assembly and method manufacturing an engine block assembly and related components. A casted engine block assembly includes a cylinder block portion. The cylinder block portion includes a plurality of cylinder block openings disposed therein, a cylinder block flange portion positioned at a top of the cylinder block portion and a cylinder block crankcase portion disposed at a base of the cylinder block. The cylinder block flange portion is configured for coupling the cylinder block to a cylinder head. The cylinder block portion includes a plurality of cylinder block walls extending between the cylinder block flange portion and the cylinder block crankcase portion and positioned about the plurality of cylinder block openings. The cylinder block walls house a plurality of internal channels. The plurality of cylinder block walls are void of enclosed openings extending through at least one of the cylinder block walls in the plurality of cylinder block walls.

A novel cylinder head arrangement for an in-line four cylinder or eight cylinder engine. A modified arrangement allows additional space for installation of wider rocker arm assemblies used for variable valve lift (VVL), cylinder deactivation (CDA) and other types of variable valve actuation (VVA). In one embodiment, cam towers adjacent the end two cylinders are not used. At least one end support is used, which may be an outboard bearing on a camshaft for each end. The wider rocker assemblies may then be installed. In another embodiment, cam towers adjacent the inner two cylinders are eliminated and a single camshaft support piece with a support bearing is installed between the inner cylinders to provide support for the camshafts. The wider rocker assemblies may then be installed on at least one of the middle cylinders. A novel oil control valve operates latches in switching rocker arm assemblies.

A cylinder block includes a body part where a cylinder is formed, an outer wall part made of fiber reinforced resin and surrounding an outer circumference of the body part, and a metal member attached to the outer wall part. The outer wall part is comprised of an inner layer surrounding the outer circumference of the body part, and an outer layer surrounding an outer circumference of the inner layer. A density of reinforcing fiber contained in the outer layer is higher than a density of reinforcing fiber contained in the inner layer. The metal member is attached to the outer wall part so as to contact the outer layer. The reinforcing fiber contained in the outer layer has an electric insulating property.

A cylinder block includes a body part where a cylinder is formed, an outer wall part made of fiber reinforced resin and surrounding an outer circumference of the body part, and a metal member attached to the outer wall part. The outer wall part is comprised of an inner layer surrounding the outer circumference of the body part, and an outer layer surrounding an outer circumference of the inner layer. A density of reinforcing fiber contained in the outer layer is higher than a density of reinforcing fiber contained in the inner layer. The metal member is attached to the outer wall part so as to contact the outer layer. The reinforcing fiber contained in the outer layer has an electric insulating property.

The invention relates to a power unit, in particular for a hybrid vehicle, comprising a two-cylinder reciprocating piston engine comprising two pistons guided in two cylinders in tandem arrangement, and two counter-rotating crankshafts connected to the pistons by connecting rods, a generator which is rotatable in the same direction as the first crankshaft and in the opposite direction to the second crankshaft, and a balancer shaft which is rotatable in the same direction as the second crankshaft and in the opposite direction to the first crankshaft. The generator is operatively connected directly to the first crankshaft by a first traction mechanism and the balancer shaft is operatively connected directly to the second crankshaft by a second traction mechanism. The balancer shaft and/or the second crankshaft support(s) a flywheel mass element. The invention further relates to a vehicle, in particular a hybrid vehicle, having such a power unit.

An engine includes: a crankcase; a cover that is connected to the crankcase at a mating surface of the cover inclined toward an inner side in a vehicle width direction in going downward when the engine is mounted to a vehicle body, the cover covering a protruding end of a rotary shaft; and attachment bosses that are formed to be integral with the cover, have a predetermined height from the mating surface, and accept fastening members for fastening the cover to the crankcase. Accordingly, when mounted on a two-wheeled motor vehicle, the engine can restrain protrusion in the vehicle width direction and can be disposed at a position as low as possible with reference to the vehicle.

A cylinder block includes a metal body part having a cylinder, and an outer wall part made of fiber reinforced resin, surrounding an outer circumference of the body part. A part of the outer wall part at BDC side in a cylinder axis direction contacts a bottom wall forming part. The outer wall part is comprised of an inner layer surrounding the outer circumference of the body part, and an outer layer surrounding an outer circumference of the inner layer. A density of reinforcing fiber contained in the outer layer is higher than that in the inner layer. A thickness of a part of the inner layer at BDC side in the cylinder axis direction is greater than that of the TDC-side inner layer. A thickness of a part of the outer layer at TDC side in the cylinder axis direction is greater than that of the BDC-side outer layer.

A cylinder block assembly includes a cylinder block having cylinders and a plurality of crank caps fixed to the cylinder block. The crank caps are arranged such that one of the crank caps is disposed on each of both sides of each of the cylinders in the alignment direction and among the plurality of crank caps arranged in line, each of a center crank cap located at a center position and two side crank caps respectively located at both ends has a hole or a groove in such a manner as to be more easily deformable than intermediate crank caps each of which is located between the center crank cap and one of the side crank caps when a load is received from the crankshaft.

A structural frame is provided. The structural frame includes a bottom surface, first and second cylinder block sidewall engaging surfaces, the first and second cylinder block sidewall engaging surfaces positioned above the bottom surface at a height that is above a centerline of a crankshaft support included in a cylinder block when the structural frame is coupled to the cylinder block.