Abstract: An opposed-piston engine has a cylinder block with a plurality of cylinders arranged inline, with each cylinder including an intake port longitudinally separated from an exhaust port. The engine's air handling system includes open intake and exhaust chambers in the cylinder block. The open chamber constructions eliminate the need for multi-pipe manifolds and smooth the flow of charge air.

Abstract: In a fuel injection spray pattern for an opposed piston engine, the individual spray plumes have both radial and tangential components with respect to an injection axis (102, 114, 121), which adds a swirl component to a spray pattern of fuel directly injected into the combustion chamber of the opposed piston engine.

Abstract: A strategy to cold-start an opposed-piston engine includes, before injecting fuel, preventing air flow through the engine while cranking the engine to heat air retained in the engine, followed by controlling mass air flow through and fuel injection into a cylinder of the engine according to cold-start schedules so as to create and preserve heat for stable engine firing and transition to an idling state of operation.

Abstract: A strategy to cold-start an opposed-piston engine includes, before injecting fuel, preventing air flow through the engine while cranking the engine to heat air retained in the engine, followed by controlling mass air flow through and fuel injection into a cylinder of the engine according to cold-start schedules so as to create and preserve heat for stable engine firing and transition to an idling state of operation.

Abstract: An opposed-piston internal combustion engine with one or more ported cylinders and uniflow scavenging includes fuel injectors supported at compound angles with respect to the cylinders in order to directly inject spray patterns of fuel in opposing directions through the side walls of the cylinders.

Abstract: Exhaust temperature management strategies for an opposed-piston, two-stroke engine with EGR are based on control of a ratio of the mass of fresh air and external EGR delivered to a cylinder to the mass of the trapped charge (density of the delivered charge multiplied by the trapped volume at port closing).

Abstract: A combustion chamber for an opposed-piston engine includes a squish zone defined between circumferential peripheral areas of opposing end surfaces of the pistons, a cavity defined by one or more bowls in the end surfaces, and at least one injection port that extends radially through the squish zone into the cavity. The cavity has a cross-sectional shape that imposes a tumbling motion on air flowing from the squish zone into the cavity.

Abstract: In an air handling system of a uniflow-scavenged, two-stroke cycle opposed-piston engine, one or more engine operating state parameters are sensed, numerical values of air handling parameters based on trapped conditions in a cylinder of the engine at the last port closing of an engine operating cycle are determined in response to the sensed parameters, the numerical values are evaluated, and one or more of the numerical values is adjusted in response to the evaluation. The adjusted numerical values are used to control charge air flow and EGR flow in the air handling system.

Abstract: The timing or phasing of port openings and closings during operation of an opposed-piston engine is varied in response to changing engine speeds and loads by changing crankshaft phasing.

Abstract: A combustion chamber for an opposed-piston engine includes a squish zone defined between circumferential peripheral areas of opposing end surfaces of the pistons, a cavity defined by one or more bowls in the end surfaces, and at least one injection port that extends radially through the squish zone into the cavity. The cavity has a cross-sectional shape that imposes a tumbling motion on air flowing from the squish zone into the cavity. Opposing spray patterns of fuel are injected into the combustion chamber. In some aspects, the opposing spray patterns are injected along a major axis of the combustion chamber.

Abstract: A combustion chamber for an opposed-piston engine includes a squish zone defined between circumferential peripheral areas of opposing end surfaces of the pistons, a cavity defined by one or more bowls in the end surfaces, and at least one injection port that extends radially through the squish zone into the cavity. The cavity has a cross-sectional shape that imposes a tumbling motion on air flowing from the squish zone into the cavity.

Abstract: In a two-stroke opposed-piston engine, a ported cylinder with a pair of opposed pistons is equipped with a decompression port including a valve and a passage with an opening through the cylinder wall that is located between the cylinder's intake and exhaust ports. The decompression port enables release of compressed air from the cylinder after the intake and exhaust ports are closed. The valve is opened to permit compressed air to be released from the cylinder through the passage, and closed to retain compressed air in the cylinder. Engine braking is supported by release of compressed air through the decompression port into an exhaust channel when the pistons are at or near top dead center positions as the cycle transitions from the intake/compression stroke to the power/exhaust stroke. Compression release from the cylinder after intake and exhaust port closure can also support other engine operations.

Abstract: An opposed-piston engine includes a ported cylinder and a pair of pistons disposed to reciprocate in the bore of the cylinder. A combustion chamber is defined by opposing shaped piston end surfaces as the pistons approach respective top dead center (TDC) locations in the bore. At the end of scavenging, the shaped end surfaces of the pistons interact with swirl to produce turbulence in the charge air motion in the combustion chamber; the additional bulk motions include tumble. Fuel is injected into the turbulent charge air motion along a major axis, of the combustion chamber.

Abstract: A two-stroke, opposed-piston engine with one or more ported cylinders and uniflow scavenging includes an exhaust gas recirculation (EGR) construction that provides a portion of the exhaust gasses produced by the engine for mixture with charge air to control the production of NOx during combustion.

Abstract: A combustion chamber construction for opposed-piston engines includes an elongated, bilaterally symmetrical shape referenced to a major axis and a pair of injection ports located on the major axis when the pistons are near respective top center positions. The combustion chamber is defined between a bowl in the end surface of a first piston of a pair of pistons and mirrored ridges protruding from the end surface of a second piston of the pair. Each ridge includes a central portion that curves toward a periphery of the end surface of the second piston and which transitions to flanking portions that curve away from the periphery. The ridge configuration imparts a substantially spherical configuration to a central portion of the combustion chamber where swirling motion of charge air is conserved.

Abstract: A two-stroke, opposed-piston engine with one or more ported cylinders and uniflow scavenging includes an exhaust gas recirculation (EGR) construction that provides a portion of the exhaust gasses produced by the engine for mixture with charge air to control the production of NOx during combustion.

Abstract: In a two-stroke opposed-piston engine, a ported cylinder with a pair of opposed pistons is equipped with a decompression port including a valve and a passage with an opening through the cylinder wall that is located between the cylinder's intake and exhaust ports. The decompression port enables release of compressed air from the cylinder after the intake and exhaust ports are closed. The valve is opened to permit compressed air to be released from the cylinder through the passage, and closed to retain compressed air in the cylinder. Engine braking is supported by release of compressed air through the decompression port into an exhaust channel when the pistons are at or near top dead center positions as the cycle transitions from the intake/compression stroke to the power/exhaust stroke. Compression release from the cylinder after intake and exhaust port closure can also support other engine operations.

Abstract: An opposed-piston internal combustion engine with one or more ported cylinders and uniflow scavenging includes fuel injectors supported at compound angles with respect to the cylinders in order to directly inject spray patterns of fuel in opposing directions through the side walls of the cylinders.

Abstract: A combustion chamber for an opposed-piston engine includes a squish zone defined between circumferential peripheral areas of opposing end surfaces of the pistons, a cavity defined by one or more bowls in the end surfaces, and at least one injection port that extends radially through the squish zone into the cavity. The cavity has a cross-sectional shape that imposes a tumbling motion on air flowing from the squish zone into the cavity. Opposing spray patterns of fuel are injected into the combustion chamber. In some aspects, the opposing spray patterns are injected along a major axis of the combustion chamber.

Abstract: An EGR system compensates for differing EGR flows and/or exhaust temperatures and can maintain the cooler exit temperature above the critical temperature, thereby reducing the possibility of EGR cooler fouling. A plurality of exhaust gas recirculation cooler modules is disposed between an exhaust gas passage and an air passage. The cooler modules receive exhaust gas from the exhaust gas passage and supply the received exhaust gas to the air passage for recirculation into an intake manifold. Each of the cooler modules includes a cooler portion, a bypass portion, and a flow control device. The cooler portion and the bypass portion are arranged such that fluid flowing through the cooler portion and the bypass portion flows therethrough without flowing through the other of the cooler portion and the bypass portion. The cooler portion reduces a temperature of the fluid flowing through the cooler portion.