A water jacket for a cylinder head includes: an upper body disposed at an upper part of the cylinder head inside the cylinder head and through which a coolant flows; a lower body disposed under the upper body inside the cylinder head and through which the coolant flows; and a connector disposed corresponding to a position of an exhaust valve between the upper body and the lower body and integrally connected to the upper body and the lower body. Tt least one penetration hole is formed in the connector along a length direction.

A supercharging device for an engine includes an electric supercharger which supercharges intake air, an intercooler which cools intake air discharged from the electric supercharger; and an intake manifold which is disposed substantially horizontally, and is configured to communicate between a downstream end of the intercooler in an intake air flow direction, and intake ports. The downstream end of the intercooler is located on a lower end of the intercooler. The downstream end of the intercooler is disposed substantially at the same height as an upstream end of the intake ports. The electric supercharger is disposed below the intercooler along a surface of the engine on an intake side where the intake ports are opened.

A power device includes: a plurality of shafts; and a case that rotatably supports the plurality of shafts. At least one of the plurality of shafts has a protruding end portion protruding outward from the case at least at one end portion in an axial direction. An output unit capable of rotationally driving a driven device is at the protruding end portion.

A flat plane crankshaft for an in-line four cylinder engine includes eight crank arms. A fourth crank arm and a fifth crank arm are respectively provided with counter weights. Each of a width of the fourth crank arm and a width of the fifth crank arm is configured to be smaller than a width of a second crank arm. Each of a width of the third crank arm and a width of the sixth crank arm is configured to be greater than the width of the second crank arm.

An engine includes a cylinder body, a cylinder head, and an ignition device including spark plugs. The engine also includes an intake device connected to intake ports, an exhaust device connected to exhaust ports, pistons, and a crankshaft connected to the pistons by connecting rods. Explosion intervals of the cylinders are 270, 180, 90, and 180 as crank angles. The engine further includes a discomfort eliminator which, when the engine speed is lower than a predetermined value, makes the indicated mean effective pressure of at least one of two cylinders having an explosion interval of 90 lower than the indicated mean effective pressures of the other cylinders having an explosion interval of not 90. The engine causes unequal-interval explosions but produces little change in the driving energy per unit time during an operating state in which an occupant is liable to feel torque fluctuations.

An internal combustion engine provided with a cylinder block able to move relative to a crankcase is provided with a block movement mechanism arranged just at one side of the internal combustion engine, a pair of guide walls provided at the crankcase, a support member supporting a side surface of the cylinder block, and a pushing member pushing against a side surface of the cylinder block. Further, at the guide wall at the side of arrangement of the block movement mechanism, the support member is attached to the top side from the position of attachment of the other end part of the connecting member and the pushing member is attached to the bottom side from the position of attachment of the other end part of the connecting member, while at the guide wall at the opposite side from the side of arrangement of the block movement mechanism, the support member is attached to the bottom side (bottom side of cylinder block) a predetermined space from pushing member.

An offset in-line four cylinder engine has reduced vibration generated by a secondary inertia couple based on lateral pressures from pistons. A reference line passes through a shaft center of a crankshaft and is parallel or substantially parallel to cylinder axes of four cylinders as viewed in the axial direction of the crankshaft. As viewed in the axial direction of the crankshaft, the direction in which the reference line extends is referred to as first direction, and the direction perpendicular to the first direction is referred to as second direction. A distance between the shaft center of a first balancer shaft and the reference line as measured in the second direction is different from the distance between the shaft center of a second balancer shaft and the reference line as measured in the second direction, or a magnitude of a first unbalancing portion is different from a magnitude of the second unbalancing portion.

A hybrid drive system for a motor vehicle, and a method for operating a motor vehicle. The hybrid drive system includes an amplidyne-type generator and a counterpoise engine to provide the power required for charging the storage batteries and providing supplemental drive energy (acceleration) to the motor vehicle.

A control device for a hybrid vehicle is, in the process of stopping an internal combustion engine of the vehicle, capable of making twist angle fluctuation reduction control and crank angle position control mutually compatible. When a request for stopping the internal combustion engine has been issued, twist angle fluctuation reduction control is implemented without implementing crank angle position control, until, in the process of bringing the engine to a stopped state, the rotational speed of the internal combustion engine drops below the resonant rotational speed region of the torsional damper; and, after the rotational speed of the internal combustion engine has dropped below the resonant rotational speed region of the torsional damper in the process of bringing the engine to a stopped state, crank angle position control is implemented without implementing twist angle fluctuation reduction control, until stopping of the internal combustion engine has been completed.

When a stop request to the engine is issued, it is determined whether or not all of the drive cams are large cams. When it is determined that at least one of the small cams is included in the drive cams, the engine is continued to drive for a while and a switch control for switching the drive cams from the small cams to the large cams is executed within the duration. A self-holding type solenoid is used to switch between the small cams and the large cams. In the switch control, a permission to stop the engine is output at a timing when the pin protrudable section of the final cylinder #2 has elapsed.