A method of assisting ignition of a dedicated exhaust gas recirculation (D-EGR) cylinder in a spark-ignited internal combustion engine. The spark igniter has an internal air passage that receives pressurized air and carries the pressurized air down to an exit port in the vicinity of the spark gap of the igniter.

A method of assisting ignition of a dedicated exhaust gas recirculation (D-EGR) cylinder in a spark-ignited internal combustion engine. The spark igniter has an internal air passage that receives pressurized air and carries the pressurized air down to an exit port in the vicinity of the spark gap of the igniter.

A prechamber sparkplug assembly includes a sparkplug, and a sparkplug housing having a prechamber tip. The sparkplug housing includes a plug bore centered on a longitudinal axis of the sparkplug housing and receiving the sparkplug, an inside radial wall extending around the plug bore, and an outside radial wall. A cooling cavity is formed between the inside radial wall and the outside radial wall. Coolant ports extend through the outside radial wall and fluidly connect to the cooling cavity to place the cooling cavity in fluid communication with a water jacket in a cylinder head.

A prechamber sparkplug assembly includes a sparkplug, and a sparkplug housing having a prechamber tip. The sparkplug housing includes a plug bore centered on a longitudinal axis of the sparkplug housing and receiving the sparkplug, an inside radial wall extending around the plug bore, and an outside radial wall. A cooling cavity is formed between the inside radial wall and the outside radial wall. Coolant ports extend through the outside radial wall and fluidly connect to the cooling cavity to place the cooling cavity in fluid communication with a water jacket in a cylinder head.

A fuel injector assembly for an internal combustion engine includes a proximal end portion, a distal end portion, and a fuel injector extending at least to the distal end portion, the fuel injector including a fuel opening. The fuel injector assembly also includes a chamber formed between the proximal and distal end portions, a flame passage extending from the chamber to the distal end portion, and an atomizer configured to provide atomization of liquid fuel injected into the chamber.

A fuel injector assembly for an internal combustion engine includes a proximal end portion, a distal end portion, and a fuel injector extending at least to the distal end portion, the fuel injector including a fuel opening. The fuel injector assembly also includes a chamber formed between the proximal and distal end portions, a flame passage extending from the chamber to the distal end portion, and an atomizer configured to provide atomization of liquid fuel injected into the chamber.

Methods and systems are provided for an engine, including an engine cylinder coupled to a cylinder head, and a pre-chamber. The pre-chamber includes a first end proximal to the cylinder head, a spark gap, and pre-chamber walls enclosing an internal volume including a dead volume. The dead volume includes all of the internal volume positioned between the first end and the spark gap. A moveable element is positioned in the internal volume and fluidly coupled to the dead volume, wherein moving the moveable element changes a ratio of the dead volume to the internal volume. In this way, combustion conditions may be enhanced at a plurality of engine conditions.

Methods and systems are provided for an engine, including an engine cylinder coupled to a cylinder head, and a pre-chamber. The pre-chamber includes a first end proximal to the cylinder head, a spark gap, and pre-chamber walls enclosing an internal volume including a dead volume. The dead volume includes all of the internal volume positioned between the first end and the spark gap. A moveable element is positioned in the internal volume and fluidly coupled to the dead volume, wherein moving the moveable element changes a ratio of the dead volume to the internal volume. In this way, combustion conditions may be enhanced at a plurality of engine conditions.

An ignition system has an ignition plug and an ignition control unit that controls the ignition plug. When an engine is in a predetermined operating state, the ignition control unit performs ignition control after top dead center to perform ignition after the compression top dead center. The ignition system has an airflow support structure that facilitates the flow of airflow through a discharge gap at least after the compression top dead center. The ignition system is configured such that due to the airflow support structure and the timing of the ignition, airflow at a flow rate of 5 m/s or more flows through the discharge gap during a spark period after top dead center, which is the generation period of the discharge spark in the ignition control after top dead center.

An object is to improve scavenging performance of a pre-combustion chamber connected to a main combustion chamber via an orifice and suppress reduction in combustion performance of an internal combustion engine. This control device for an internal combustion engine including a main combustion chamber and a pre-combustion chamber having at least one orifice between the pre-combustion chamber and the main combustion chamber, includes a first control device which controls operation of an ignition coil to generate spark discharge at a spark plug, thus combusting fuel gas, and a second control device which controls operation of the ignition coil at a timing other than the timing of combusting the fuel gas, to promote scavenging of the pre-combustion chamber.