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 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 fuel injector mounting assembly in an opposed-piston engine allows for mounting of a fuel injector in a cylinder block without significantly deforming the wall of the cylinder into which the injector is configured to deliver fuel. The fuel injector mounting assembly includes a clamping arrangement to clamp the fuel injector to the cylinder block, an elongate tubular sleeve that sheathes a nozzle portion of the fuel injector, and a spanner nut attached to the elongate tubular sleeve. Clamping loads applied to retain the fuel injector in the cylinder block are controlled by the spanner nut.

A method for coating a surface with a coating jet containing coating particles includes forming the coating jet from at least two partial jets. The method also includes forming one of the exit channels as a spray channel for a first gas stream containing the coating particles. The method also includes forming the other of the exit channels as a control channel. In case of a deviation of the ascertained spray angle (α) from the predetermined target spray angle, the method also includes increasing the volume flow of a first partial jet of the at least two partial jets, and decreasing the volume flow of a second partial jet of the at least two partial jets.

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.

A cylinder assembly with a cylinder liner and a sleeve is provided that includes features that reduce coolant flow stagnation. The sleeve encloses a center section of the cylinder liner to form cooling channels that removes excess heat from the combustion area of the cylinder. The cylinder liner includes features for cooling between bridges in the cylinder's exhaust port.

In ported engine constructions, cooling of piston crowns and cylinder liners results in reduction or elimination of bore/liner distortions, thus ensuring circularity of the bore/piston interface throughout engine operation. Consequently, the need for heavily-tensioned piston rings is eliminated. Such engine constructions incorporate annular low-tension compression seals on the pistons, which substantially reduce port bridge wear during all phases of engine operation while also limiting blow-by during combustion.

A reciprocating cylinder seal assembly (10, 10) has an elastomeric seal, where separate inner (16, 16) and an outer (18, 18) valve seal retainers are located within the reciprocating cylinder seal assembly. The reciprocating cylinder seal assembly (10, 10) better controls radial run out than past seals in reciprocating cylinder engines. Further, the reciprocating cylinder seal assembly may have a scraper (42) that is in contact with the outer valve seal retainer (18).

An engine block for an opposed-piston engine 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 plurality of fastener bores. The second center section defines a second cylinder half bore having a second longitudinal axis and a second plurality of fastener bores that extend from a first end thereof to a second end thereof. The second center section is configured to abut the first center section such that: the first and second cylinder half bores are in fluid communication with one another to collectively form a single cylinder; the first and second longitudinal axes are offset from one another; and the first and second pluralities of fastener bores are aligned with one another for receiving a first plurality of fasteners to join the first and second center sections to one another.

A reciprocating cylinder seal assembly (10, 10) has an elastomeric seal, where separate inner (16, 16) and an outer (18, 18) valve seal retainers are located within the reciprocating cylinder seal assembly. The reciprocating cylinder seal assembly (10, 10) better controls radial run out than past seals in reciprocating cylinder engines. Further, the reciprocating cylinder seal assembly may have a scraper (42) that is in contact with the outer valve seal retainer (18).