An internal combustion engine, including a piston, a cylinder, and an output shaft, wherein the piston is arranged for reciprocating motion within the cylinder, driven by combustion, and the piston is coupled to the output shaft by a coupling such that said reciprocating motion of the piston drives rotation of the output shaft, wherein the engine has increased engine part commonality. The internal combustion engine may include a first cylinder bank and a second cylinder bank, the first cylinder bank having a first cylinder head, the second cylinder bank having a second cylinder head, and the first cylinder head and the second cylinder head being formed as common parts such that they are interchangeable. An internal combustion engine, including a piston, a cylinder, and an output shaft, wherein the piston is arranged for reciprocating motion within the cylinder, driven by combustion, and the piston is coupled to the output shaft by a coupling such that said reciprocating motion of the piston drives rotation of the output shaft, wherein the engine includes a crankcase formed of a plurality of separable like parts, each of the like parts being cast as a common part.

An opposed piston engine has a driveshaft with a spaced apart cams mounted thereon. Each cam has a circumferential cam shoulder of a curvilinear shape selected to enhance flow through intake and exhaust ports. The curvilinear shape may be a segmented polynomial shape forming lobes which lobes are asymmetrical so that the lobe wavelength distance from a first trough to the lobe peak of an ascending shoulder portion of the lobe is greater than the lobe wavelength distance from the peak to a second trough of a descending shoulder portion of the lobe. Opposing cam shoulders may be shaped so as to always be converging or diverging from one another.

An opposed piston engine has a driveshaft with at least two combustion cylinders serially aligned along a center cylinder axis so as to be coaxial, where the center cylinder axis is parallel with but spaced apart from the driveshaft axis. A cam is disposed between adjacent combustion cylinders, as well as adjacent the outermost end of each combustion cylinder in order to reciprocatingly drive piston pairs disposed in each combustion cylinder.

A crank and connecting rod mechanism having an angularly disposed connecting rod and mirror image gear sets, each comprising: a crank gear rotatably mounted on a crank gear shaft, having a crankpin pivotally connected to and driven by the connecting rod, the crankpin following the path of a roulette of a centered trochoid about a first stationary gear as the crank gear is driven about the first stationary gear and a crankshaft driven gear is driven about a second stationary gear, a counterbalanced radial arm affixed to a drive shaft at a pivot point of the counterbalanced radial arm, the counterbalanced radial arm driving the drive shaft at the pivot point and the crank gear shaft at an outer radial arm bearing, the drive shaft driving a drive shaft gear, which drives an output gear that drives an output shaft.

This invention relates to the field of opposed-piston engines having two pistons in one cylinder configured to have facing heads. Specifically, this is an engine with two crankshafts, two piston heads facing each other in a single cylinder, with the following features: compact size relative to a comparable design, improved or equivalent performance to a comparable design as a result of any of the following: locating crankshafts in a different plane from the cylinder axes; the use of shared duct structures; and the use of an embedded compressor chamber for efficient operation to cover all volumetric requirements, fulfilling the entire thermodynamic cycle, and performing in addition the sweeping and overloading of air or an air/fuel mixture in the cylinder combustion chamber in each revolution of two or more crankshafts, either with or without advancement between the crankshafts.

A high-performance internal combustion engine includes: a crankshaft chamber; at least two cylinder chambers; a crankshaft linkage mechanism, disposed in the crankshaft chamber; at least two pistons, connected to the crankshaft linkage mechanism and accommodated in the cylinder chambers; an inlet pipe, only communicated with the crankshaft chamber; at least two flow guiding pipes, having one end thereof only communicated with the crankshaft chamber and another end thereof only communicated with the cylinder chamber; and a check valve unit, including a check valve disposed at a connecting location of the inlet pipe and the crankshaft chamber, and two first switch valves disposed at connecting locations of the flow guiding pipes and the cylinder chambers. Accordingly, the working efficiency of the high-performance internal combustion engine can be increased.

An internal combustion engine includes a first cylinder block, a first head, a first overhead structure, a second cylinder block, a second head, a second overhead structure, a first through-bolt aperture, and a first through-bolt. The first head is in contact with the first cylinder block. The first overhead structure is in contact with the first head opposite the first cylinder block. The second cylinder block is in contact with the first cylinder block opposite the first head. The second head is in contact with the second cylinder block opposite the first cylinder block. The second overhead structure is in contact with the second head opposite the second cylinder block. The first through-bolt aperture is defined through the first overhead structure, the first head, the first cylinder block, the second cylinder block, the second head, and the second overhead structure.

An internal combustion engine includes a first cylinder block, a first head, a first overhead structure, a second cylinder block, a second head, a second overhead structure, a first through-bolt aperture, and a first through-bolt. The first head is in contact with the first cylinder block. The first overhead structure is in contact with the first head opposite the first cylinder block. The second cylinder block is in contact with the first cylinder block opposite the first head. The second head is in contact with the second cylinder block opposite the first cylinder block. The second overhead structure is in contact with the second head opposite the second cylinder block. The first through-bolt aperture is defined through the first overhead structure, the first head, the first cylinder block, the second cylinder block, the second head, and the second overhead structure.

An internal combustion engine, including a piston, a cylinder, and an output shaft, wherein the piston is arranged for reciprocating motion within the cylinder, driven by combustion, and the piston is coupled to the output shaft by a coupling such that said reciprocating motion of the piston drives rotation of the output shaft, wherein the engine has increased engine part commonality. The internal combustion engine may include a first cylinder bank and a second cylinder bank, the first cylinder bank having a first cylinder head, the second cylinder bank having a second cylinder head, and the first cylinder head and the second cylinder head being formed as common parts such that they are interchangeable. An internal combustion engine, including a piston, a cylinder, and an output shaft, wherein the piston is arranged for reciprocating motion within the cylinder, driven by combustion, and the piston is coupled to the output shaft by a coupling such that said reciprocating motion of the piston drives rotation of the output shaft, wherein the engine includes a crankcase formed of a plurality of separable like parts, each of the like parts being cast as a common part.