Engine for producing mechanical energy by internal combustion of a fuel includes a shaft and a crank arm attached to the shaft. The engine further includes a casing, where the interior of the casing forms a hollow cavity dimensioned to allow the crank arm to rotate within the hollow cavity and the crank arm is capable of making a seal with the interior surface of the casing to block fluid passage. The interior of the casing also includes a bypass area that allows fluid passage around the crank arm. A first valve is positioned adjacent to the bypass area and a second valve is positioned adjacent to the bypass area opposite from the first valve. The first valve and the second valve are configured to block fluid passage when closed.

A valve drive comprising a camshaft with base shaft, a lobe pack mounted on the base shaft and comprising three cam lobes. Two actuator bodies are associated with two actuator pins each connected to a valve of a cylinder of the engine. The lobe pack is axially displaceable along the base shaft so as to for each actuator body change cam lobe aligned therewith. A middle cam lobe has a shape leaving an actuator body aligned therewith uninfluenced thereby. In a first position of the lobe pack a first of the actuator bodies is aligned with and hit and moved by a first cam lobe and the other, second actuator body is aligned with the middle cam lobe, and in a second position the second actuator body is aligned with and hit and moved by a third cam lobe and the first actuator body is aligned with the middle cam lobe.

A valve drive comprising a camshaft with base shaft, a lobe pack mounted on the base shaft and comprising three cam lobes. Two actuator bodies are associated with two actuator pins each connected to a valve of a cylinder of the engine. The lobe pack is axially displaceable along the base shaft so as to for each actuator body change cam lobe aligned therewith. A middle cam lobe has a shape leaving an actuator body aligned therewith uninfluenced thereby. In a first position of the lobe pack a first of the actuator bodies is aligned with and hit and moved by a first cam lobe and the other, second actuator body is aligned with the middle cam lobe, and in a second position the second actuator body is aligned with and hit and moved by a third cam lobe and the first actuator body is aligned with the middle cam lobe.

A compact and efficient Z-twin internal combustion engine is described herein. The Z-twin internal combustion engine comprises horizontally opposed cylinder arrangement that allows for vibration cancellation. The Z-twin engine comprises a central shared cam that drives angled side valves of both the opposing cylinders, thereby greatly reducing moving parts and thus provides a significantly more efficient angled valve approach.

A four-stroke internal combustion engine is disclosed. A camshaft and a crankshaft if the engine are synchronised to rotate at a same rotational speed. A first linkage arrangement is configured to change the motion of an exhaust valve head. A second linkage arrangement is configured to change the motion of the intake valve head. A control unit is configured for controlling the first linkage arrangement to selectively prevent or reduce the motion of the exhaust valve head and for controlling the second linkage arrangement to selectively prevent or reduce the motion of the intake valve head.

A four-stroke internal combustion engine is disclosed. A camshaft and a crankshaft if the engine are synchronized to rotate at a same rotational speed. A first linkage arrangement is configured to change the motion of an exhaust valve head. A second linkage arrangement is configured to change the motion of the intake valve head. A control unit is configured for controlling the first linkage arrangement to selectively prevent the motion of the exhaust valve head and for controlling the second linkage arrangement to selectively prevent the motion of the intake valve head.

A four-stroke internal combustion engine is disclosed. A camshaft and a crankshaft if the engine are synchronized to rotate at a same rotational speed. A first linkage arrangement is configured to change the motion of an exhaust valve head. A second linkage arrangement is configured to change the motion of the intake valve head. A control unit is configured for controlling the first linkage arrangement to selectively prevent the motion of the exhaust valve head and for controlling the second linkage arrangement to selectively prevent the motion of the intake valve head.

An internal combustion engine (10) with variable valve timing has one or more valve shafts (38, 44) connected to stepper motors (54) for angularly positioning the one or more valve shafts (38, 44) relative to an engine block (12). Flow passages (50, 52) are formed into the one or more valve shafts (38, 44) for passing intake air and exhaust gases into and from the engine (10). Sensors (58, 60 and 62) are located adjacent a crankshaft (28) and the one or more valve shafts (38, 44) for determining crankshaft positions and valve shaft positions relative to the engine block (12). An engine control unit (56) receives crank shaft and valve shaft position signals and emits control signals to the stepper motors (54) to selectively operate the engine in two stroke, four stroke, six stroke, eight stroke, and ten stroke modes. Electrically controlled clutches (74 and 76) are mounted to respective ones of the crankshaft (28) and the valve shafts (38, 44), and connected by a timing chain (72) for actuating to provide backup valve shaft.

An internal combustion engine (10) with variable valve timing has one or more valve shafts (38, 44) connected to stepper motors (54) for angularly positioning the one or more valve shafts (38, 44) relative to an engine block (12). Flow passages (50, 52) are formed into the one or more valve shafts (38, 44) for passing intake air and exhaust gases into and from the engine (10). Sensors (58, 60 and 62) are located adjacent a crankshaft (28) and the one or more valve shafts (38, 44) for determining crankshaft positions and valve shaft positions relative to the engine block (12). An engine control unit (56) receives crank shaft and valve shaft position signals and emits control signals to the stepper motors (54) to selectively operate the engine in two stroke, four stroke, six stroke, eight stroke, and ten stroke modes. Electrically controlled clutches (74 and 76) are mounted to respective ones of the crankshaft (28) and the valve shafts (38, 44), and connected by a timing chain (72) for actuating to provide backup valve shaft.

A valve drive comprising a camshaft with base shaft, a lobe pack mounted on the base shaft and comprising three cam lobes. Two actuator bodies are associated with two actuator pins each connected to a valve of a cylinder of the engine. The lobe pack is axially displaceable along the base shaft so as to for each actuator body change cam lobe aligned therewith. A middle cam lobe has a shape leaving an actuator body aligned therewith uninfluenced thereby. In a first position of the lobe pack a first of the actuator bodies is aligned with and hit and moved by a first cam lobe and the other, second actuator body is aligned with the middle cam lobe, and in a second position the second actuator body is aligned with and hit and moved by a third cam lobe and the first actuator body is aligned with the middle cam lobe.