A plasma jet plug includes: a tubular insulator having an axial hole; a center electrode disposed inside the axial hole; metal shell disposed on an outer circumference of the insulator; and an orifice electrode electrically connected to the metal shell and disposed on a front side of the insulator. A plasma generating cavity is formed by a surface of the center electrode, an inner surface of the insulator, and an inner surface of the orifice electrode. In the plasma jet plug, a shortest path length D1 of a surface path is greater than or equal to 5 times an aerial gap G, where the surface path extends, inside the cavity, from a surface of the center electrode via an inner surface of the insulator to an inner surface of the orifice electrode, and the aerial gap G is a shortest distance between the center electrode and the orifice electrode.

A sparkplug assembly having a prechamber volume is operatively associated with the combustion chamber of an internal combustion engine such that the prechamber volume is in fluid communication with the combustion chamber. To purge exhaust gasses from the prechamber volume prior to ignition, the sparkplug assembly is operatively associated with a high-pressure air/fuel source that directs a pressurized air/fuel purge charge to the prechamber volume. The pressurized air/fuel purge charge may be at stoichiometric conditions. The high-pressure air/fuel source is configured to direct the pressurized air/fuel purge charge during at least a portion of the compression stroke to maintain a largely stoichiometric mixture of air and fuel in the prechamber volume.

System and methods for an internal combustion engine are described. In one example, the internal combustion engine may be a boosted internal combustion engine that includes an igniter that is at least partially positioned in a cylinder of the internal combustion engine. The igniter includes an orifice that is configured to release exhaust from a pre-chamber of the igniter.

An internal combustion engine includes an cylinder block defining at least one cylinder, a cylinder head at least partially defining a combustion chamber for each cylinder of the cylinder block, and a spark plug bore formed in the cylinder head for each cylinder, the spark plug bore connecting to the combustion chamber and configured to receive a spark plug. A turbulent jet ignition (TJI) pre-chamber insert is press-fit into the spark plug bore, and defining an internal combustion pre-chamber in fluid communication with the combustion chamber.

A system for igniting a mixture in an internal combustion engine includes an elongate plug body generally residing around a center longitudinal axis and adapted to couple to the internal combustion engine. The system also includes a first ignition body residing about an end of the plug body and a second ignition body adjacent the first ignition body to define a flame kernel initiation gap between the second ignition body and the first ignition body. The system also includes a transversely extending cap at the end of the plug body that is longitudinally spaced from the plug body by a support comprising a leg that is radially offset from the center longitudinal axis, the support defining a peripheral opening around a perimeter of the cap where a total radially-facing area of the support is less than a total area of the peripheral opening.

In one embodiment, a combustion system for an engine is disclosed. The system includes a cylinder block that defines a cylinder bore and opposing pre-chambers located along a circumference of the cylinder bore. The system also includes a fuel injector located equidistant from the circumference of the cylinder bore that injects fuel in a direction perpendicular to a diameter of the cylinder bore. The system further includes spark plugs located within the pre-chambers that ignite at least a portion of the fuel from the fuel injector to direct ignition flames into the cylinder bore.

A prechamber system for an internal combustion engine has a prechamber, a fuel introduction device, a dead space which connects the fuel introduction device to the prechamber. A channel is provided which connects the prechamber to the dead space.

A system for igniting a mixture in an internal combustion engine includes an elongate plug body generally residing around a center longitudinal axis and adapted to couple to the internal combustion engine. The system also includes a first ignition body residing about an end of the plug body and a second ignition body adjacent the first ignition body to define a flame kernel initiation gap between the second ignition body and the first ignition body. The system also includes a transversely extending cap at the end of the plug body that is longitudinally spaced from the plug body by a support comprising a leg that is radially offset from the center longitudinal axis, the support defining a peripheral opening around a perimeter of the cap where a total radially-facing area of the support is less than a total area of the peripheral opening.

An engine includes a cylinder having an internal combustion chamber and extending longitudinally, a cylinder head coupled to the cylinder, and a fuel-fed pre-chamber positioned within a portion of the cylinder head. The pre-chamber includes a pre-chamber volume and plurality of nozzle holes extending from the pre-chamber volume. The engine also includes an ignition source positioned longitudinally above the pre-chamber volume and a locating member positioned on at least one of the pre-chamber and the cylinder head. The locating member is configured to position the pre-chamber in a predetermined orientation within the cylinder head.

A system for igniting a mixture in an internal combustion engine includes an elongate plug body generally residing around a center longitudinal axis and adapted to couple to the internal combustion engine. The system also includes a first ignition body residing about an end of the plug body and a second ignition body adjacent the first ignition body to define a flame kernel initiation gap between the second ignition body and the first ignition body. The system also includes a transversely extending cap at the end of the plug body that is longitudinally spaced from the plug body by a support comprising a leg that is radially offset from the center longitudinal axis, the support defining a peripheral opening around a perimeter of the cap where a total radially-facing area of the support is less than a total area of the peripheral opening.