In one aspect, an engine ignition apparatus for a natural gas engine may include a housing including a drive piston, a floating piston, a controllable hydraulic fluid chamber located between the drive piston and the floating piston, and an ignition chamber acted on by the floating piston, the ignition chamber having an outlet formed by a plurality of orifices, the outlet being in direct communication with a combustion chamber of the engine. In another aspect, an engine ignition apparatus for a natural gas engine may include, among other features, a controllable valve connected to a hydraulic fluid chamber, and configured to open and release a hydraulic fluid from the hydraulic fluid chamber, and to close. In still another aspect, a method for controlling an engine ignition apparatus for an engine includes, among other features, controlling a volume of a hydraulic fluid chamber of an ignition apparatus.

Systems and methods are provided for a variable volume pre-chamber igniter, which may be coupled in an engine system. In one example, a method may include adjusting an internal volume of a pre-chamber igniter based on operating conditions by adjusting a position of a cap of the pre-chamber igniter, the pre-chamber igniter including a plurality of orifices fluidically coupling the pre-chamber igniter to a main combustion chamber of a cylinder of an engine. By adjusting a position of the cap, the internal volume of the pre-chamber igniter may be increased or decreased to provide reliable ignition to the cylinder across a wide range of operating conditions.

Systems and methods are provided for a variable volume pre-chamber igniter, which may be coupled in an engine system. In one example, a method may include adjusting an internal volume of a pre-chamber igniter based on operating conditions by adjusting a position of a cap of the pre-chamber igniter, the pre-chamber igniter including a plurality of orifices fluidically coupling the pre-chamber igniter to a main combustion chamber of a cylinder of an engine. By adjusting a position of the cap, the internal volume of the pre-chamber igniter may be increased or decreased to provide reliable ignition to the cylinder across a wide range of operating conditions.

In one aspect, an engine ignition apparatus for a natural gas engine may include a housing including a drive piston, a floating piston, a controllable hydraulic fluid chamber located between the drive piston and the floating piston, and an ignition chamber acted on by the floating piston, the ignition chamber having an outlet formed by a plurality of orifices, the outlet being in direct communication with a combustion chamber of the engine. In another aspect, an engine ignition apparatus for a natural gas engine may include, among other features, a controllable valve connected to a hydraulic fluid chamber, and configured to open and release a hydraulic fluid from the hydraulic fluid chamber, and to close. In still another aspect, a method for controlling an engine ignition apparatus for an engine includes, among other features, controlling a volume of a hydraulic fluid chamber of an ignition apparatus.

Operating an internal combustion engine system includes advancing a prechamber piston in a fuel delivery igniter to push a main charge of fuel from a prechamber into a cylinder, and advancing the prechamber piston to compression-ignite a pilot charge within the prechamber. Combustion gases of the pilot charge are conveyed into the cylinder to ignite the main charge. Operation of the engine system provides sparkless gaseous fuel ignition.

An ignition system for an internal combustion engine includes an igniter having an igniter housing with a combustion prechamber formed therein, and a piston movable within the igniter housing to increase a pressure of an ignition charge of fuel and air within the combustion prechamber to an autoignition threshold. The ignition system includes a hydraulic actuator to apply an actuating force to the piston. Related methodology is disclosed.

An ignition system for an internal combustion engine includes an igniter having an igniter housing with a combustion prechamber formed therein, and a piston movable within the igniter housing to increase a pressure of an ignition charge of fuel and air within the combustion prechamber to an autoignition threshold. The ignition system includes a hydraulic actuator to apply an actuating force to the piston. Related methodology is disclosed.

An ignition system for an internal combustion engine includes an igniter having an igniter housing with a combustion prechamber formed therein, and a piston movable within the igniter housing to increase a pressure of an ignition charge of fuel and air within the combustion prechamber to an autoignition threshold. The ignition system includes a hydraulic actuator to apply an actuating force to the piston. Related methodology is disclosed.

An ignition system for an internal combustion engine includes an igniter having an igniter housing with a combustion prechamber formed therein, and a piston movable within the igniter housing to increase a pressure of an ignition charge of fuel and air within the combustion prechamber to an autoignition threshold. The ignition system includes a hydraulic actuator to apply an actuating force to the piston. Related methodology is disclosed.

An ignition system for a gaseous fuel engine includes an igniter and an actuator structured to apply an actuating force to a piston within the igniter, to autoignite an ignition charge of fuel and air within the igniter. A housing of the igniter includes a gas orifice having a flow area that is increased between a combustion pre-chamber in the igniter and a main combustion chamber in the engine, to limit velocity of outgoing combustion gases to below a threshold velocity for engine mis-fire.