Abstract: An internal combustion engine is provided. Facing pistons eliminate a cylinder head, thereby reducing heat losses through a cylinder head. Facing pistons also halve the stroke that would be required for one piston to provide the same compression ratio, and the engine can thus be run at higher revolutions per minute and produce more power. An internal sleeve valve is provided for space and other considerations. A combustion chamber size-varying mechanism allows for adjustment of the minimum size of an internal volume to increase efficiency at partial-power operation. Variable intake valve operation is used to control engine power.

Abstract: A cam can rotate on a camshaft of an internal combustion engine. A rocker arm that actuates a valve of the internal combustion engine can include a rocker pivot connection point located on a distal side of a valve component from a proximate end of the rocker arm that is deflected by action of the cam. The rocker arm can include a contact point located between the rocker pivot point and the proximate end. The contact point can act on the valve component to actuate the valve. The rocker pivot connection point can be translated such that it is closer to or further from the cam. This translation can be used to vary valve lift and/or valve timing. The cam can have a three-dimensional profile to provide different actuation distance of the rocker arm. Systems, methods, and articles of manufacture consistent with one or more of these features are described.

Abstract: A gear or gear assembly, for example for use in a gear train or other drive system relating to an engine such as an internal combustion engine, can be matched to the thermal expansion other engine components, such as for example a support structure for gear shafts on which gears of the gear train rotate, while maintaining structural strength in the teeth and other contact surfaces of the gear.

Abstract: A sleeve valve assembly. The assembly includes a valve seat, a sleeve valve and an oil path-defining piece. The sleeve valve includes a distal end with a cavity. The distal end contacts the valve seat when the sleeve valve is located in a closed position. The oil path-defining piece includes an inlet port, an outlet port and a plurality of cooling passages. The flange of the sleeve valve is slidably in contact with the oil path-defining piece such that cooling fluid travelling into the inlet port and through the cooling passages enters into the cavity before exiting out the exit port.

Abstract: An internal combustion engine is provided. Facing pistons eliminate a cylinder head, thereby reducing heat losses through a cylinder head. Facing pistons also halve the stroke that would be required for one piston to provide the same compression ratio, and the engine can thus be run at higher revolutions per minute and produce more power. An internal sleeve valve is provided for space and other considerations. A combustion chamber size-varying mechanism allows for adjustment of the minimum size of an internal volume to increase efficiency at partial-power operation. Variable intake valve operation is used to control engine power.

Abstract: A sleeve valve assembly. The assembly includes a valve seat, a sleeve valve and an oil path-defining piece. The sleeve valve includes a distal end with a cavity. The distal end contacts the valve seat when the sleeve valve is located in a closed position. The oil path-defining piece includes an inlet port, an outlet port and a plurality of cooling passages. The flange of the sleeve valve is slidably in contact with the oil path-defining piece such that cooling fluid travelling into the inlet port and through the cooling passages enters into the cavity before exiting out the exit port.

Abstract: A system and method are disclosed for fabricating and running an engine in two modes. The first mode is an efficiency mode having a high compression ratio and efficiency for low to medium loads. The second mode is a power mode having high power density for higher loads. The system may use a lean mixture in the efficiency mode, which mixture is made richer for more power in the power mode. The system may also use ignition timing to allow the efficiency mode and the high power mode to be at the same mixture.

Abstract: Various embodiments of methods and systems for varying the compression ratio in opposed-piston engines are disclosed herein. In one embodiment, an opposed-piston engine can include a first phaser operably coupled to a first crankshaft and a second phaser operably coupled to a corresponding second crankshaft. The phase angle between the crankshafts can be changed to reduce or increase the compression ratio in the corresponding combustion chamber to optimize or at least improve engine performance under a given set of operating conditions.

Abstract: An internal combustion engine is provided. Facing pistons eliminate a cylinder head, thereby reducing heat losses through a cylinder head. Facing pistons also halve the stroke that would be required for one piston to provide the same compression ratio, and the engine can thus be run at higher revolutions per minute and produce more power. An internal sleeve valve is provided for space and other considerations. A combustion chamber size-varying mechanism allows for adjustment of the minimum size of an internal volume to increase efficiency at partial-power operation. Variable intake valve operation is used to control engine power.

Abstract: Various embodiments of methods and systems for varying the compression ratio in opposed-piston engines are disclosed herein. In one embodiment, an opposed-piston engine can include a first phaser operably coupled to a first crankshaft and a second phaser operably coupled to a corresponding second crankshaft. The phase angle between the crankshafts can be changed to reduce or increase the compression ratio in the corresponding combustion chamber to optimize or at least improve engine performance under a given set of operating conditions.

Abstract: An internal combustion engine is provided. Facing pistons eliminate a cylinder head, thereby reducing heat losses through a cylinder head. Facing pistons also halve the stroke that would be required for one piston to provide the same compression ratio, and the engine can thus be run at higher revolutions per minute and produce more power. An internal sleeve valve is provided for space and other considerations. A combustion chamber size-varying mechanism allows for adjustment of the minimum size of an internal volume to increase efficiency at partial-power operation. Variable intake valve operation is used to control engine power.

Abstract: An internal combustion engine is operable in an efficiency mode providing a first power output range between zero and a transition power output and in a power mode providing a second power output range between the transition power output and a maximum power output. The efficiency mode can include a first ignition timing and a first air/fuel ratio of the mixture to avoid premature auto-ignition, and the power mode can include a second ignition timing and a second air/fuel ratio of the mixture to avoid premature auto-ignition of the mixture. To further enable knock free operation of such an engine, turbulence can be imparted to the mixture to promote a faster burn duration and high temperatures that may lead to premature auto-ignition of the mixture can be avoided.

Abstract: Various types of valve systems are disclosed herein. In one embodiment, a positive control reciprocating sleeve valve system for use with an internal combustion engine includes opening and closing rockers controlled by corresponding opening and closing cam lobes. In one aspect of this embodiment, interference can be designed into the valve control system to provide additional “hold-closed” force to hold the valve against its seat during a portion of the engine cycle. In another aspect of this embodiment, positive control valve systems can include compliant components and systems, hydraulic systems, pneumatic systems, and/or mechanical spring systems to control valve lash, facilitate sealing, etc.

Abstract: Various embodiments of methods and systems for varying the compression ratio in opposed-piston engines are disclosed herein. In one embodiment, an opposed-piston engine can include a first phaser operably coupled to a first crankshaft and a second phaser operably coupled to a corresponding second crankshaft. The phase angle between the crankshafts can be changed to reduce or increase the compression ratio in the corresponding combustion chamber to optimize or at least improve engine performance under a given set of operating conditions.