Disclosed is a procedure to minimize NOx during varying engine loads in a 4-stroke diesel engine including at least one cylinder with a cylinder head, first piston on a connecting rod, one actuator mounted on the cylinder head and one of the actuator operated second piston lockable via a hydraulic circuit in various positions in a combustion chamber. The second piston, at the latest during the current compression stroke is actuated by the actuator and locked in the combustion chamber, where it by the first piston introduced air is compressed in a predetermined compression ratio to meet an existing engine load wherein the free operated inlet valve is brought to close the inlet stroke at a piston position where the volume of the combustion air as introduced at the end of the compression stroke gives the predetermined compression ratio and that the injector injects the stated amount of fuel.

Disclosed is a procedure to minimize NOx during varying engine loads in a 4-stroke diesel engine including at least one cylinder with a cylinder head, first piston on a connecting rod, one actuator mounted on the cylinder head and one of the actuator operated second piston lockable via a hydraulic circuit in various positions in a combustion chamber. The second piston, at the latest during the current compression stroke is actuated by the actuator and locked in the combustion chamber, where it by the first piston introduced air is compressed in a predetermined compression ratio to meet an existing engine load wherein the free operated inlet valve is brought to close the inlet stroke at a piston position where the volume of the combustion air as introduced at the end of the compression stroke gives the predetermined compression ratio and that the injector injects the stated amount of fuel.

An engine system includes a prechamber in fluid communication with a main chamber of an engine cylinder via a plurality of nozzles located along a first end of the prechamber. The engine system also includes a prechamber ignition device interfacing an interior of the prechamber, and a prechamber piston slidably disposed in the interior of the prechamber between the first end and a second end of the prechamber, wherein a variable volume is defined in the interior of the prechamber between the prechamber piston and the first end of the prechamber. The engine system further includes a spring positioned between the second end of the prechamber and the prechamber piston, wherein the spring is configured to exert a spring force on the prechamber piston.

An engine system includes a prechamber in fluid communication with a main chamber of an engine cylinder via a plurality of nozzles located along a first end of the prechamber. The engine system also includes a prechamber ignition device interfacing an interior of the prechamber, and a prechamber piston slidably disposed in the interior of the prechamber between the first end and a second end of the prechamber, wherein a variable volume is defined in the interior of the prechamber between the prechamber piston and the first end of the prechamber. The engine system further includes a spring positioned between the second end of the prechamber and the prechamber piston, wherein the spring is configured to exert a spring force on the prechamber piston.

An internal combustion engine includes a pre-chamber. In another aspect, pressure within a pre-chamber is equal to or greater than pressure within a main combustion chamber at least prior to ignition in the main combustion chamber. In yet another aspect, internal combustion engine control software automatically controls pressure within a turbulent jet ignition pre-chamber, controls a valve-actuator to admit a fuel-air charge into the pre-chamber, and causes an igniter to initiate combustion in the pressurized pre-chamber. This also permits the rate of combustion to be controlled in the primary chamber regardless of the air-fuel ratio or the diluent fraction in the main chamber. Another aspect employs a pre-chamber purge pump with separate air and fuel injection.

An internal combustion engine includes a pre-chamber. In another aspect, pressure within a pre-chamber is equal to or greater than pressure within a main combustion chamber at least prior to ignition in the main combustion chamber. In yet another aspect, internal combustion engine control software automatically controls pressure within a turbulent jet ignition pre-chamber, controls a valve-actuator to admit a fuel-air charge into the pre-chamber, and causes an igniter to initiate combustion in the pressurized pre-chamber. This also permits the rate of combustion to be controlled in the primary chamber regardless of the air-fuel ratio or the diluent fraction in the main chamber. Another aspect employs a pre-chamber purge pump with separate air and fuel injection.

Disclosed is a procedure to minimize NOx during varying engine loads in a 4-stroke diesel engine including at least one cylinder with a cylinder head, first piston on a connecting rod, one actuator mounted on the cylinder head and one of the actuator operated second piston lockable via a hydraulic circuit in various positions in a combustion chamber. The second piston, at the latest during the current compression stroke is actuated by the actuator and locked in the combustion chamber, where it by the first piston introduced air is compressed in a predetermined compression ratio to meet an existing engine load wherein the free operated inlet valve is brought to close the inlet stroke at a piston position where the volume of the combustion air as introduced at the end of the compression stroke gives the predetermined compression ratio and that the injector injects the stated amount of fuel.

An internal combustion engine includes a piston reciprocally moving in at least one cylinder. An intake valve controls the supply of fresh air into a power chamber defined within the cylinder by the moving piston. An ancillary chamber is fluidly connected with the power chamber via a flow-through valve. An auxiliary piston is reciprocally movable in the ancillary chamber and determines the volume of the ancillary chamber. A fuel supply valve introduces fuel into the ancillary chamber. The flow-through valve, the fuel supply valve and the auxiliary piston are moved such that no fresh air from the power chamber goes into the ancillary chamber and such that fuel is expelled from the ancillary chamber into the power chamber via the flow-through valve for combustion with fresh air compressed in the power chamber.

An internal combustion engine includes a piston reciprocally moving in at least one cylinder. An intake valve controls the supply of fresh air into a power chamber defined within the cylinder by the moving piston. An ancillary chamber is fluidly connected with the power chamber via a flow-through valve. An auxiliary piston is reciprocally movable in the ancillary chamber and determines the volume of the ancillary chamber. A fuel supply valve introduces fuel into the ancillary chamber. The flow-through valve, the fuel supply valve and the auxiliary piston are moved such that no fresh air from the power chamber goes into the ancillary chamber and such that fuel is expelled from the ancillary chamber into the power chamber via the flow-through valve for combustion with fresh air compressed in the power chamber.

An engine includes an engine housing defining a pair of cylinders, a pair of ignitor cylinders and a crankcase, a pair of cylinder heads connected to the engine housing and enclosing the pair of cylinders, a pair of spark plugs connected to the pair of cylinder heads and in communication with the pair of cylinders, a piston assembly in communication with the pair of cylinders, a rocker arm connected to the piston assembly, a connecting rod connected to the rocker arm, and a drive shaft disposed within the crankcase and connected to the connecting rod, a pair of ignitor cylinder plugs fit within the pair of ignitor cylinders, ignitor piston rod apertures formed though the engine housing, and rod aperture plugs fit within the piston rod apertures.