A valve system/method suitable for an internal combustion engine (ICE), compressor pump, vacuum pump, and/or reciprocating mechanical device is disclosed. The system/method is optimized for construction of a four-stroke ICE. The rudimentary system incorporates an intake engine block cover (IEC) and exhaust engine block cover (EEC) that enclose an intake rotary valve disc (IVD) and exhaust rotary valve disc (EVD) that control intake/exhaust flow through a respective intake rotary valve port (IVP) and an exhaust rotary valve port (EVP) into and out of a combustion cylinder that provides power to a piston and crankshaft. An intake multi-staged valve (IMV) and exhaust multi-staged valve (EMV) provide intake and exhaust flow control for the IVD/IVP and EVD/EVP. An enhanced system may include a variety of intake/exhaust port seals (IPS/EPS), forced induction/discharge (FIN), centrifugal advance (CAD), and/or cooling channel spool (ICS/ECS).

A reciprocating exhaust valve for a two-stroke internal combustion engine has a shaft for connection to a valve actuator, the shaft defining a reciprocation axis of the valve, the reciprocation axis defining a longitudinal direction of the valve; and a blade having: a first end having an arcuate edge, a second end connected to the shaft, two side portions, and a central portion. The blade has a first end portion adjacent the first end that includes a part of the central portion and of each of the two side portions. A width of the central portion is greater than a width of each of the side portions. In the first end portion, a thickness of the part of each of the two side portions is greater than a thickness of the part of the central portion.

An exhaust valve system for a two-stroke internal combustion engine having: at least one exhaust valve movable between open and closed positions; an actuator for moving the at least one exhaust valve; a valve position sensor; a controller communicating with the actuator and the valve position sensor. The controller being programmed for: controlling the actuator to attempt to move the at least one exhaust valve to a desired one of the open and closed positions; determining if the at least one exhaust valve has failed to reach the desired position based on the position of the at least one exhaust valve sensed by the valve position sensor; and controlling the actuator to move the at least one exhaust valve to an intermediate position when the at least one exhaust valve has failed to reach the desired position.

An exhaust valve assembly for a two-stroke internal combustion engine has a housing adapted for connection to an engine block of the two-stroke internal combustion engine; an electric actuator having an electric motor, the electric motor being disposed in the housing; and at least one reciprocating exhaust valve operatively connected to the electric actuator. The at least one exhaust valve is linearly movable by the electric motor. A portion of the at least one exhaust valve is disposed in the housing.

The present disclosure is directed towards an engine assembly comprising a crankcase, a crankshaft, a lubrication system and fluid guide arrangement. During rotation the crankshaft is configured to drive a crankcase fluid flow in a crankcase chamber. The lubrication system comprises a lubricant drain for a drain fluid flow therethrough extending to a drain aperture at the crankcase chamber. The fluid guide arrangement is located adjacent or in proximity to the drain aperture. The fluid guide arrangement is configured for guiding crankcase fluid flow away from the drain aperture and/or for reducing the pressure of the crankcase fluid flow past the drain aperture, such that drain fluid flows from the lubricant drain.

Provided is an apparatus for supplying lubricant to a timing chain installed in an engine, the apparatus including an injection hole configured for injecting lubricant from an oil pump, and an inner cover having a guide groove configured to receive lubricant injected from the injection hole and guide the lubricant toward a engagement place between the timing chain and a sprocket, wherein the inner cover has a guide groove provided at a position facing an injection hole of a counter surface portion that is spaced apart from a cylinder block and faces the guide groove.

An annular cylinder liner includes an annular body defining a longitudinal axis, a radial direction perpendicular to the longitudinal axis, a circumferential direction, a first longitudinal end, a second longitudinal end, and a liner length measured from the first longitudinal end to the second longitudinal end along the longitudinal axis. The annular body also includes a shoulder that is disposed at the first longitudinal end, defining a shoulder axial thickness measured along the longitudinal axis. A ratio of the liner length to the shoulder axial thickness ranges from 24.0 to 46.0.

The present disclosure is directed towards an engine assembly comprising a crankcase, a crankshaft, a lubrication system and fluid guide arrangement. During rotation the crankshaft is configured to drive a crankcase fluid flow in a crankcase chamber. The lubrication system comprises a lubricant drain for a drain fluid flow therethrough extending to a drain aperture at the crankcase chamber. The fluid guide arrangement is located adjacent or in proximity to the drain aperture. The fluid guide arrangement is configured for guiding crankcase fluid flow away from the drain aperture and/or for reducing the pressure of the crankcase fluid flow past the drain aperture, such that drain fluid flows from the lubricant drain.

Embodiments are directed toward an engine. In some embodiments, the engine includes a water pump and a balancer shaft. In some embodiments, the water pump has a plain bearing. In some embodiments, plain bearing is supplied with pressurized oil. In some embodiments, the balancer shaft drives the water pump as well as cam shafts.

An engine device having a flywheel housing in which a flywheel that is rotated integrally with a crankshaft is accommodated on one side portion of a cylinder block, in which the cylinder block is integrally formed with housing bracket portions each protruding in a direction away from the crankshaft from each of opposite side portions of the cylinder block extending along a crankshaft axial direction, the housing bracket portions protruding from end portions of the opposite side portions close to the one side portion, and a space surrounded by the one side portion, the housing bracket portions, and the flywheel housing constitutes a gear case for accommodating therein a gear train.