Abstract: A prechamber sparkplug includes a sparkplug housing forming a prechamber, and an electrode within the prechamber and defining a spark gap with the sparkplug housing. The prechamber sparkplug further includes a valvular element such as a check, a valve, or a tesla valve, structured to preferentially permit ejection of fluids from the prechamber over admission of fluids to the prechamber. Varying relative restriction of fluids into versus out of the prechamber can limit a charge density within the prechamber extending sparkplug service life, particularly in high power density engine applications. Related apparatus and methodology is also disclosed.

Abstract: Operating a gaseous fuel engine system includes urging a mixture containing a gaseous hydrogen fuel and air into a pocket in an igniter fluidly connected to a cylinder to form an ignition charge, and igniting the ignition charge via a flame kernel formed by energizing spark electrodes of the igniter. The method further includes igniting a main charge containing the gaseous hydrogen fuel via a flame jet of the ignition charge from the igniter. The pocket is shielded from the cylinder sufficiently to form within the pocket a flow field protecting the flame kernel, while fluidly connected to the cylinder sufficiently to clear the pocket of residual combustion gases.

Abstract: A spark plug includes a central electrode member and an outer electrode member. The central electrode member includes a central base and a plurality of electrode prongs extending in an axial direction from the central base. The outer electrode member surrounds the central electrode member. The outer electrode member includes a wall that is radially spaced from the plurality of electrode prongs to allow a series of electric arcs to form between the wall and the plurality of electrode prongs. The outer electrode member and the central electrode member are sized and positioned relative to one another such that a first rate of wear of the outer electrode member, along a longitudinal axis of the spark plug, is substantially equal to a second rate of wear of the central electrode member along the longitudinal axis.

Abstract: Operating a gaseous fuel engine system includes urging a mixture containing a gaseous hydrogen fuel and air into a pocket in an igniter fluidly connected to a cylinder to form an ignition charge, and igniting the ignition charge via a flame kernel formed by energizing spark electrodes of the igniter. The method further includes igniting a main charge containing the gaseous hydrogen fuel via a flame jet of the ignition charge from the igniter. The pocket is shielded from the cylinder sufficiently to form within the pocket a flow field protecting the flame kernel, while fluidly connected to the cylinder sufficiently to clear the pocket of residual combustion gases.

Abstract: A spark plug includes a central electrode member and an outer electrode member. The central electrode member includes a central base and a plurality of electrode prongs extending in an axial direction from the central base. The outer electrode member surrounds the central electrode member. The outer electrode member includes a wall that is radially spaced from the plurality of electrode prongs to allow a series of electric arcs to form between the wall and the plurality of electrode prongs. The outer electrode member and the central electrode member are sized and positioned relative to one another such that a first rate of wear of the outer electrode member, along a longitudinal axis of the spark plug, is substantially equal to a second rate of wear of the central electrode member along the longitudinal axis.

Abstract: A spark plug includes a central electrode member and an outer electrode member. The central electrode member includes a central base and a plurality of electrode prongs extending in an axial direction from the central base. The outer electrode member surrounds the central electrode member. The outer electrode member includes a wall that is radially spaced from the plurality of electrode prongs to allow a series of electric arcs to form between the wall and the plurality of electrode prongs. The outer electrode member and the central electrode member are sized and positioned relative to one another such that a first rate of wear of the outer electrode member, along a longitudinal axis of the spark plug, is substantially equal to a second rate of wear of the central electrode member along the longitudinal axis.

Abstract: A spark plug includes a central electrode member and an outer electrode member. The central electrode member includes a central base and a plurality of electrode prongs extending in an axial direction from the central base. The outer electrode member surrounds the central electrode member. The outer electrode member includes a wall that is radially spaced from the plurality of electrode prongs to allow a series of electric arcs to form between the wall and the plurality of electrode prongs. The outer electrode member and the central electrode member are sized and positioned relative to one another such that a first rate of wear of the outer electrode member, along a longitudinal axis of the spark plug, is substantially equal to a second rate of wear of the central electrode member along the longitudinal axis.

Abstract: A spark plug includes a central electrode member and an outer electrode member. The central electrode member includes a central base and a plurality of electrode prongs extending in an axial direction from the central base. The outer electrode member surrounds the central electrode member. The outer electrode member includes a wall that is radially spaced from the plurality of electrode prongs to allow a series of electric arcs to form between the wall and the plurality of electrode prongs. The outer electrode member and the central electrode member are sized and positioned relative to one another such that a first rate of wear of the outer electrode member, along a longitudinal axis of the spark plug, is substantially equal to a second rate of wear of the central electrode member along the longitudinal axis.

Abstract: A spark plug includes a central electrode member and an outer electrode member. The central electrode member includes a central base and a plurality of electrode prongs extending in an axial direction from the central base. The outer electrode member surrounds the central electrode member. The outer electrode member includes a wall that is radially spaced from the plurality of electrode prongs to allow a series of electric arcs to form between the wall and the plurality of electrode prongs. The outer electrode member and the central electrode member are sized and positioned relative to one another such that a first rate of wear of the outer electrode member, along a longitudinal axis of the spark plug, is substantially equal to a second rate of wear of the central electrode member along the longitudinal axis.

Abstract: A spark plug includes a central electrode member and an outer electrode member. The central electrode member includes a central base and a plurality of electrode prongs extending in an axial direction from the central base. The outer electrode member surrounds the central electrode member. The outer electrode member includes a wall that is radially spaced from the plurality of electrode prongs to allow a series of electric arcs to form between the wall and the plurality of electrode prongs. The outer electrode member and the central electrode member are sized and positioned relative to one another such that a first rate of wear of the outer electrode member, along a longitudinal axis of the spark plug, is substantially equal to a second rate of wear of the central electrode member along the longitudinal axis.

Abstract: A spark plug includes a central electrode member and an outer electrode member. The central electrode member includes a central base and a plurality of electrode prongs extending in an axial direction from the central base. The outer electrode member surrounds the central electrode member. The outer electrode member includes a wall that is radially spaced from the plurality of electrode prongs to allow a series of electric arcs to form between the wall and the plurality of electrode prongs. The outer electrode member and the central electrode member are sized and positioned relative to one another such that a first rate of wear of the outer electrode member, along a longitudinal axis of the spark plug, is substantially equal to a second rate of wear of the central electrode member along the longitudinal axis.

Abstract: A prechamber sparkplug includes a housing having a nozzle with a prechamber formed therein, and each of a first set and a second set of electrode prongs within the prechamber. The second set of electrode prongs downwardly depend from attachment points to the housing, and form, together with the first set of electrode prongs, spark gaps within the prechamber. Each of the anode-cathode pairs formed by the sets of electrode prongs is spaced radially inward a clearance distance from the prechamber wall to position the spark gaps in a flow of swirled gases. The flow of swirled gases displaces a flame kernel formed at the spark gaps to inhibit quenching.

Abstract: 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.

Abstract: A prechamber sparkplug includes a housing having a nozzle with a prechamber formed therein, and each of a first set and a second set of electrode prongs within the prechamber. The second set of electrode prongs downwardly depend from attachment points to the housing, and form, together with the first set of electrode prongs, spark gaps within the prechamber. Each of the anode-cathode pairs formed by the sets of electrode prongs is spaced radially inward a clearance distance from the prechamber wall to position the spark gaps in a flow of swirled gases. The flow of swirled gases displaces a flame kernel formed at the spark gaps to inhibit quenching.

Abstract: An ignition system for an engine includes a sparkplug, ignition circuitry electrically connected to the sparkplug, and an ignition control unit structured to energize the ignition circuitry to fire the sparkplug at an ignition timing, detect a fault condition caused by an abnormal response of the sparkplug to the energizing, and to energize the ignition circuitry to dry fire the sparkplug at an offset timing such as during an exhaust, stroke based on the detection of the fault condition. Dry firing the sparkplug reduces a break down voltage required to subsequently fire the sparkplug and extends sparkplug service life.

Abstract: A spark plug includes a body of revolution defining a longitudinal axis. The body has a forward axial portion with external threads, and an intermediate axial collar portion defining an axially downwardly facing sealing surface. A first electrode and a second electrode extend from the forward axial portion and define a spark gap therebetween. A hex drive portion is disposed axially above the intermediate collar portion. A gasket crush limiter includes a wall that extends axially downwardly from the intermediate axial collar portion, defining an annular pocket formed by the wall and the forward axial portion.

Abstract: A prechamber sparkplug includes a housing having a nozzle with a prechamber formed therein, and each of a first set and a second set of electrode prongs within the prechamber. The second set of electrode prongs downwardly depend from attachment points to the housing, and form, together with the first set of electrode prongs, spark gaps within the prechamber. Each of the anode-cathode pairs formed by the sets of electrode prongs is spaced radially inward a clearance distance from the prechamber wall to position the spark gaps in a flow of swirled gases. The flow of swirled gases displaces a flame kernel formed at the spark gaps to inhibit quenching.

Abstract: A crankshaft and method for manufacturing the same are disclosed. The crankshaft may comprise a web and a rod journal disposed adjacent to the web. The rod journal includes a fillet disposed proximal to the web. The fillet includes a tapered undercut having a concave shape with a graduated depth. The undercut is defined by a sweep angle and an offset angle.

Abstract: A crankshaft and method for manufacturing the same are disclosed. The crankshaft may comprise a web and a rod journal disposed adjacent to the web. The rod journal includes a fillet disposed proximal to the web. The fillet includes a tapered undercut having a concave shape with a graduated depth. The undercut is defined by a sweep angle and an offset angle.

Abstract: A gas preheater (10) that includes an exit plate (20) having first and second sides (22, 24) and a plurality of through holes (26) and at least one body (34) mounted adjacent the first side (22), the at least one body (34) having a first end (36) and a second end (38), the second end (38) located between the body first end (36) and the exit plate first side (22), at least one sidewall (40) connecting the first and second ends (36, 38), a body opening (42) in the first end (36) extending into the body (34) and defining a body inner wall (44), and a plurality of passages (46) extending between the at least one sidewall (40) and the body inner wall (44).