An engine having a cylinder fastened to the engine ease with the biconcave internal partition, which divides the cylinder into the upper and bottom parts. Sparking plugs are mounted on both sides of the partition. The upper and the bottom parts of the cylinder have side scavenging channels which connect suction spaces to the working spaces of both parts of the cylinder. The upper and bottom parts of the cylinder have inlet and outlet orifices. Inside the upper and inside the bottom part of the cylinder and the upper and bottom piston are placed respectively, while both pistons are directed towards each other by the working surfaces. The pistons are connected by a rod that is led through the linear bearing that is embedded in the partition forming a seal. The connecting rod is fastened to the bottom piston and by its other end it is connected to the crankshaft.

An example embodiment of an all-stroke-variable internal combustion engine may include a piston slidably positioned within an engine cylinder for asymmetrical reciprocation and a primary crankshaft and a half-speed crankshaft to be operatively engaged for rotation of the half-speed crankshaft at half of a speed of the primary crankshaft, wherein the rotation of the half-speed crankshaft at half of the speed of the primary crankshaft to result in the asymmetrical reciprocation of the piston so as to produce a stroke length that is independently variable over four distinct strokes of a full cycle of the all-stroke-variable internal combustion engine.

An example embodiment of an all-stroke-variable internal combustion engine may include a piston slidably positioned within an engine cylinder for asymmetrical reciprocation and a primary crankshaft and a half-speed crankshaft to be operatively engaged for rotation of the half-speed crankshaft at half of a speed of the primary crankshaft, wherein the rotation of the half-speed crankshaft at half of the speed of the primary crankshaft to result in the asymmetrical reciprocation of the piston so as to produce a stroke length that is independently variable over four distinct strokes of a full cycle of the all-stroke-variable internal combustion engine.

An example embodiment of an all-stroke-variable internal combustion engine may include a piston slidably positioned within an engine cylinder for asymmetrical reciprocation and a primary crankshaft and a half-speed crankshaft to be operatively engaged for rotation of the half-speed crankshaft at half of a speed of the primary crankshaft, wherein the rotation of the half-speed crankshaft at half of the speed of the primary crankshaft to result in the asymmetrical reciprocation of the piston so as to produce a stroke length that is independently variable over four distinct strokes of a full cycle of the all-stroke-variable internal combustion engine.

An example embodiment of an all-stroke-variable internal combustion engine may include a piston slidably positioned within an engine cylinder for asymmetrical reciprocation and a primary crankshaft and a half-speed crankshaft to be operatively engaged for rotation of the half-speed crankshaft at half of a speed of the primary crankshaft, wherein the rotation of the half-speed crankshaft at half of the speed of the primary crankshaft to result in the asymmetrical reciprocation of the piston so as to produce a stroke length that is independently variable over four distinct strokes of a full cycle of the all-stroke-variable internal combustion engine.

Throttle-at-valve apparatus, internal combustion engines employing throttle-at-valve apparatus, and methods of throttling an internal combustion engine using a throttle-at-valve apparatus, where the throttle-at-valve apparatus includes a throttle slide body disposed within a throttle slide cavity that is defined between and in fluid communication with both an unobstructed air intake passage and an intake valve of an internal combustion engine, where the air flow from the air intake passage to the intake valve is regulated by the reciprocal movement of the throttle slide body within the throttle slide cavity.

An example embodiment of an all-stroke-variable internal combustion engine may include a piston slidably positioned within an engine cylinder for asymmetrical reciprocation and a primary crankshaft and a half-speed crankshaft to be operatively engaged for rotation of the half-speed crankshaft at half of a speed of the primary crankshaft, wherein the rotation of the half-speed crankshaft at half of the speed of the primary crankshaft to result in the asymmetrical reciprocation of the piston so as to produce a stroke length that is independently variable over four distinct strokes of a full cycle of the all-stroke-variable internal combustion engine.

An example embodiment of an all-stroke-variable internal combustion engine may include a piston slidably positioned within an engine cylinder for asymmetrical reciprocation and a primary crankshaft and a half-speed crankshaft to be operatively engaged for rotation of the half-speed crankshaft at half of a speed of the primary crankshaft, wherein the rotation of the half-speed crankshaft at half of the speed of the primary crankshaft to result in the asymmetrical reciprocation of the piston so as to produce a stroke length that is independently variable over four distinct strokes of a full cycle of the all-stroke-variable internal combustion engine.

A compression ignition internal combustion engine (1), which includes a cylinder (2), a piston (3) reciprocably received within the cylinder (2), a pair of contra-rotating crankshafts (4, 5) rotatably mounted relative to the cylinder (2), a pair of connecting rods (6, 7) each having a first end (61, 71) connected to a crank journal (41, 51) of a respective one of the crankshafts (4, 5) and a second end (62, 72) connected to the piston (3). The engine (1) is configured such that the stroke of the piston (3) in a first direction toward the crankshafts (4, 5) causes each crankshaft (4, 5) to rotate by a first angle and the piston stroke in a second direction opposite the first direction causes each crankshaft (4,5) to rotate by a second angle different (β−α) from the first angle.

A compression ignition internal combustion engine (1), which includes a cylinder (2), a piston (3) reciprocably received within the cylinder (2), a pair of contra-rotating crankshafts (4, 5) rotatably mounted relative to the cylinder (2), a pair of connecting rods (6, 7) each having a first end (61, 71) connected to a crank journal (41, 51) of a respective one of the crankshafts (4, 5) and a second end (62, 72) connected to the piston (3). The engine (1) is configured such that the stroke of the piston (3) in a first direction toward the crankshafts (4, 5) causes each crankshaft (4, 5) to rotate by a first angle and the piston stroke in a second direction opposite the first direction causes each crankshaft (4,5) to rotate by a second angle different (β−α) from the first angle.