An opposed-piston engine includes an engine block, at least two intake valves, and at least two exhaust valves. The engine block includes a first center section and a second center section. The first center section defines a first cylinder half bore having a first longitudinal axis and a first open end. The second center section defines a second cylinder half bore having a second longitudinal axis and a second open end. The second longitudinal axis is offset from the first longitudinal axis. The first and second open ends overlap to form and opening therebetween that places the first and second cylinder half bores in fluid communication with one another to form a single cylinder. The intake valves are arranged at the first open end of the first cylinder half bore. The exhaust valves are arranged at the second open end of the second cylinder half bore.

An opposed-piston engine includes an engine block, at least two intake valves, and at least two exhaust valves. The engine block includes a first center section and a second center section. The first center section defines a first cylinder half bore having a first longitudinal axis and a first open end. The second center section defines a second cylinder half bore having a second longitudinal axis and a second open end. The second longitudinal axis is offset from the first longitudinal axis. The first and second open ends overlap to form and opening therebetween that places the first and second cylinder half bores in fluid communication with one another to form a single cylinder. The intake valves are arranged at the first open end of the first cylinder half bore. The exhaust valves are arranged at the second open end of the second cylinder half bore.

A linear piston engine includes a housing having a combustion chamber located between opposing first and second piston chambers. A first piston assembly is located within the first piston chamber, and a second piston assembly is located within the second piston chamber. Each piston assembly includes a piston for reciprocating within the piston chamber. The piston is located adjacent to the combustion chamber. Each piston assembly also includes a crankshaft coupled to the piston for guiding the piston through a power stroke and a return stroke, and a linear output member coupled to the piston for providing a linear output motion based on reciprocating motion of the piston.

A linear piston engine includes a housing having a combustion chamber located between opposing first and second piston chambers. A first piston assembly is located within the first piston chamber, and a second piston assembly is located within the second piston chamber. Each piston assembly includes a piston for reciprocating within the piston chamber. The piston is located adjacent to the combustion chamber. Each piston assembly also includes a crankshaft coupled to the piston for guiding the piston through a power stroke and a return stroke, and a linear output member coupled to the piston for providing a linear output motion based on reciprocating motion of the piston.

An opposed-piston internal combustion engine is configured so that one cylinder is provided with two pistons and these pistons reciprocate symmetrically with each other. The engine comprises: an expanded chamber formed at part of a wall of the cylinder positioned between the two pistons when a volume between the two pistons is the minimum and extending in a radial direction of the cylinder; an intake passage communicated with the expanded chamber; an exhaust passage communicated with the expanded chamber; an intake valve opening and closing the intake passage with respect to the expanded chamber; an exhaust valve opening and closing the exhaust passage with respect to the expanded chamber, and crankshafts respectively connected to the pistons. The expanded chamber formed so as to stick out from a wall surface of the cylinder in the same direction as axes of rotation of the crankshafts.

A parent bore cylinder block of an internal combustion, opposed-piston engine includes cooling passages that are formed using a 3-D printed casting core. The casting core can include portions that are ceramic. The parent bore cylinder block can include multiple cylinders, each cylinder with cooling passages and turbulence inducing features in those cooling passages, particularly surrounding the central portions of the cylinders.

An opposed-piston engine with two crankshafts includes a first power transducer coupled to a first crankshaft of the two crankshafts and a second power transducer coupled to a second crankshaft of the two crankshafts. The two crankshafts are not rotatably connected, and so are free to rotate independently of each other. Phase relationships between the crankshafts may be controlled by operating the power transducers to increase, or reduce, crankshaft torque. Changes in crankshaft phase relationships cause changes in opposed piston locations, which, in turn, enable control of engine performance factors.

The air handling system of an opposed-piston engine is equipped with an externally-assisted pumping element such as an electrically-assisted compressor, an electrically-assisted supercharger, or an electrically-assisted turbocharger.

The air handling system of an opposed-piston engine is equipped with an externally-assisted pumping element such as an electrically-assisted compressor, an electrically-assisted supercharger, or an electrically-assisted turbocharger.

In an opposed piston engine, an inlet piston crankshaft axis and an exhaust piston crankshaft axis both extend parallel to a central cylinder plane extending through a centerpoint of a cylinder of the engine and along a central axis of the cylinder. The inlet piston crankshaft axis and the exhaust piston crankshaft axis are both offset from the central cylinder plane. The inlet piston and the exhaust piston linked to the inlet piston crankshaft and the exhaust piston crankshaft are arranged so that the inlet piston closes an inlet port as the inlet piston moves from its bottom dead center toward its top dead center at substantially a same time as the exhaust piston closes the exhaust port as the exhaust piston moves from its bottom dead center toward its top dead center.