An air-cooled internal combustion engine including a crankshaft rotating about a crankshaft axis, a first cylinder having a first cylinder head, a second cylinder having a second cylinder head, and a blower assembly. The blower assembly includes a blower housing, a first fan, and a second fan. The first fan is positioned proximate the first cylinder and the second fan is positioned proximate the second cylinder. The first fan and the second fan are each received within the blower housing.

A split cycle internal combustion engine includes a combustion cylinder accommodating a combustion piston and a compression cylinder accommodating a compression piston. The engine also includes a controller arranged to receive an indication of a parameter associated with the combustion cylinder and/or a fluid associated therewith and to control an exhaust valve of the combustion cylinder in dependence on the indicated parameter to cause the exhaust valve to close during the return stroke of the combustion piston, before the combustion piston has reached its top dead centre position (TDC), when the indicated parameter is less than a target value for the parameter; and close on completion of the return stroke of the combustion piston, as the combustion piston reaches its top dead centre position (TDC), when the indicated parameter is equal to or greater than the target value for the parameter.

Internal combustion engine with cylinders disposed radially around an axis (Z), in each of which slides a piston carrying out reciprocating rectilinear movements, reversibly transformed into a continuous rotation of an output shaft by: an active unit and passive unit each respectively having a planet gear, the axis of which is parallel to (Z), being capable of meshing with a ring gear, being maintained on its orbit via a planet carrier and having a pitch diameter identical to the pitch radius of the corresponding ring gear. The planet gear is driven in rotation by the planet gear and/or the planet carrier. Each planet gear is respectively rigidly connected to a connecting rod having crank pins, the axes of which are parallel to the axis (Z), pass through the pitch circle of the corresponding planet gear and being capable of cooperating by contact with rods rigidly connected to the pistons.

An engine block formed according to a method that includes forming an insert, coating the insert with a bond material, placing the insert within a casting mold or die, purging the casting mold or die with an inert gas, filling the casting mold or die with molten metal to encapsulate the insert, diffusion bonding the molten metal to the insert to form a diffusion bonded insert, placing the diffusion bonded insert within a cavity of a secondary casting mold or die, filling the secondary casting mold or die with molten metal to form an engine block composite casting assembly, and casting and heat treating the engine block composite casting assembly is provided. The insert can be free of serrations for mechanical coupling between the insert and the engine block.

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.

An engine assembly includes a small air-cooled engine and a dry sump lubrication system including an external oil reservoir, wherein the dry sump lubrication system has an overall oil capacity that provides at least five hundred hours of engine oil life.

A split cycle internal combustion engine includes a combustion cylinder accommodating a combustion piston and a compression cylinder accommodating a compression piston. The engine also includes a controller arranged to receive an indication of a parameter associated with the combustion cylinder and/or a fluid associated therewith and to control an exhaust valve of the combustion cylinder in dependence on the indicated parameter to cause the exhaust valve to close during the return stroke of the combustion piston, before the combustion piston has reached its top dead centre position (TDC), when the indicated parameter is less than a target value for the parameter; and close on completion of the return stroke of the combustion piston, as the combustion piston reaches its top dead centre position (TDC), when the indicated parameter is equal to or greater than the target value for the parameter.