An opposed-piston engine optionally contains an ignition system that is at least partially contained within the combustion chamber to enhance the combustion efficiency of a fuel-air mixture within the combustion system. More specifically, the ignition system contains at least one spark plug having an elongated center electrical delivery electrode, and, an elongated ground electrode. Accordingly, the elongated electrodes extend from an area adjacent to the inner periphery of the cylinder to a radially central area within the combustion chamber. Yet further, a cooling jacket is incorporated to provide cooling of the spark plug.

A piston internal combustion engine with generator has two cylinders and cylinder heads and pistons with connecting rods and two crankshafts which are connected by gears with a ratio of 1:−1 (with opposite direction of rotation). The first crankshaft with the gear is mounted parallel to the second crankshaft with the second gear in one engine case such, that the gears engage. The first crankshaft is coupled to the first generator rotor and the second crankshaft is coupled to the second generator rotor or the flywheel. The moment of inertia of the first crankshaft assembly with the first gear and the first generator rotor is equal to the moment of inertia of the second crankshaft assembly with the second gear and the second generator rotor or flywheel. The cylinders with the pistons and are positioned perpendicularly to the plane of symmetry between the crankshafts, with the axes of the pair of cylinders lying in a plane with the both pistons being at the top dead center simultaneously.

A rotary roller motor is disclosed herein. The rotary roller motor is a four-stroke internal combustion engine, wherein the rotor “rolls” around the inside of the engine block. The rotor is a two-part rotor having an inner part with a shaft and an offset circular lobe, and an outer rotor fit around the lobe. Two barriers are provided around the rotor chamber, a compression/power barrier and an exhaust/intake barrier. The combustion chamber has a non-reversing compression barrier and a compression hold barrier regulating the combustion of gas.

A four-stroke opposed piston engine contains a drive train containing two outer crank shaft gears, and two inner synchro gears, wherein the inner synchro gears are twice the diameter of the outer crank shaft gears. Additionally, novel piston faces are presented that when fixed on opposed pistons, create annular cavities that form advantageous combustion chambers when the pistons are at top dead center.

An internal combustion engine includes combustion chambers, each having a controllable intake valve controlling an intake port, a controllable exhaust valve controlling an exhaust port, a piston, and a fuel injector. An intake manifold is connected to the intake port of each chamber. In catalytic converter warm-up mode, each chamber is driven in four-stroke operation including a 720 crank angle degrees cycle, and opens the intake port, starting to open in 90-180 CAD, and fully closes the intake port in 180-270 CAD, opens the exhaust port during the power stroke, starting in 405-495 CAD, opens the intake port during the exhaust stroke, starting in 610-690 CAD, and fully closes the exhaust port during the exhaust stroke in 630-710 CAD. Exhaust gas is forced into the intake manifold by the piston, mixing fuel and exhaust in the intake manifold, and fully closes the intake port in 700 to 720+20 CAD.

A movable piston head is provided; the piston head has a head cylinder and a upper piston, a first port and a second port on the head cylinder wall, a first path and a second path in the upper piston, when the first port aligns with the first path horizontally, or the second port aligns with the second path horizontally, the combustion chamber is communicating with external, the upper piston moves up and down to perform intake, exhaust, compression, seal the combustion chamber from external. A variable compression ratio engine and a shifted minimum combustion chamber volume engine are provided. Fuel efficiency is improved and manufacturing cost is reduced, different working sequences and compression ratio control are also provided in the invention.

A detection apparatus for detecting a cam angle of a 4-stroke multi-cylinder engine in which explosion intervals are unequal intervals, includes a detection target member configured to rotate in synchronism with a camshaft, and first and second cam angle sensors configured to detect rotation of the detection target member. The detection target member includes a plurality of first detection target portions arranged, at equal pitches, as many as the number of cylinders of the multi-cylinder engine. The second cam angle sensor is arranged while being shifted in the rotation direction with respect to the first cam angle sensor such that any one of detection signals of the plurality of first detection target portions by the first cam angle sensor and the second cam angle sensor is output at a timing corresponding to each explosion interval.

The air cleaner (32) comprises a base member (41) including a base wall (41A) extending substantially horizontally, and a cover member (42) attached to an upper side of the base wall to jointly define a filter chamber (70) for receiving a filter element (43) therein. The air cleaner further includes a passage member (44) communicating with the filter chamber and incorporated with a plurality of air ejection pipes (44C) each surrounded by an annular air inlet passage (44E) fitted with guide vanes (44D) for rotating the air flow, and a case member (45) defining separation chambers (45C) for separating dust from the rotating air flow. The passage member (44) is interposed between the cover member (42) and the case member (45).

An internal combustion engine includes a reduction gear including: at one end thereof, a small-diameter gear in mesh with a one-way clutch gear; and at an opposite end thereof, a large-diameter gear in mesh with a drive gear of a starter motor. The starter motor has a driveshaft disposed below a rotation axis of the reduction gear and within a width of the large-diameter gear as viewed in an axial direction. Accordingly, in the internal combustion engine, it is possible to efficiently dispose components in a reentrant space formed between a crankcase and a cylinder block.

An expanded torque system of an internal combustion engine includes a cylinder having an upper piston bore, a lower piston bore and a lower action chamber. An upper piston is connected to the upper link rod and reciprocally moves in the upper piston bore. A linkage unit has a link block coupled to the upper link rod. A lower piston moves in the lower piston bore and is connected to the link block. A lower link rod is disposed at the lower action chamber and is pivotally coupled between the linkage unit and a lower link rod pivoting handle. A crank shaft is disposed at the lower action chamber and has a main shaft and the lower link rod pivoting handle eccentrically connected to the main shaft. An oil ring with oil outlets is disposed at the top of the lower action chamber and communicates with a main oil duct.