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.

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.

In an internal combustion engine, an oil return passage extending from a breather chamber can be formed without increasing the number of component parts and without increasing the size of the internal combustion engine. The internal combustion engine (1) comprises an engine block (30) defining a cylinder (2); a case member (19) fastened to a lower part of the engine block to define a crank chamber jointly with the engine block; a bearing member (50) fastened to the engine block in the crank chamber to rotatably support a crankshaft; a breather chamber (113) defined in the engine block; an inlet passage (112) formed in the engine block to communicate the crank chamber with the breather chamber; a connection pipe (114) communicating the breather chamber with an intake device; and an oil return passage (150) formed at least in the bearing member, and extending from a bottom part of the breather chamber to an oil return port (147) opening at an outer surface of the bearing member. The oil return port may be provided in a lower part of the bearing member.

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.

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 a unitized intake and exhaust engine block cover (UEC) that enclose an intake rotary valve cylinder (IVC) and exhaust rotary valve cylinder (EVC) 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 IVC/IVP and EVC/EVP. An enhanced system may include a variety of intake/exhaust port seals (IPS/EPS), forced induction (FIN), forced discharge (FID), centrifugal advance (CAD), and/or cooling channel spool (ICS/ECS).

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 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 two-stroke ICE. The rudimentary system incorporates an intake engine block cover (IEC) and exhaust engine block cover (EEC) that enclose an intake rotary valve cylinder (IVC) and exhaust rotary valve cylinder (EVC) 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. Intake/exhaust multi-staged valves (IMV/EMV) provide intake/exhaust flow control for the IVC/IVP and EVC/EVP. An enhanced system may include a variety of intake/exhaust port seals (IPS/EPS), forced induction/discharge (FIN/FID), centrifugal advance (CAD/ICA/ECA), and/or cooling channel spool (ICS/ECS).

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.

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 a unitized intake and exhaust engine block cover (UEC) that enclose an intake rotary valve cylinder (IVC) and exhaust rotary valve cylinder (EVC) 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 IVC/IVP and EVC/EVP. An enhanced system may include a variety of intake/exhaust port seals (IPS/EPS), forced induction (FIN), forced discharge (FID), centrifugal advance (CAD), and/or cooling channel spool (ICS/ECS).

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 two-stroke ICE. The rudimentary system incorporates an intake engine block cover (IEC) and exhaust engine block cover (EEC) that enclose an intake rotary valve cylinder (IVC) and exhaust rotary valve cylinder (EVC) 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. Intake/exhaust multi-staged valves (IMV/EMV) provide intake/exhaust flow control for the IVC/IVP and EVC/EVP. An enhanced system may include a variety of intake/exhaust port seals (IPS/EPS), forced induction/discharge (FIN/FID), centrifugal advance (CAD/ICA/ECA), and/or cooling channel spool (ICS/ECS).