Abstract: An annular notch is provided in the body seat associated with the nozzle valve of an ALCO-type diesel injector. The notch extends from (i) an upper edge that is on the seat and is above the imaginary edge that would have been the sac inlet edge had the notch not been provided to (ii) a lower edge below such imaginary edge. The notch has a lowest wall that, at least at the portion of its length where such lowest wall approaches such lower edge, has a given angle-to-vertical of less than 60°.

Abstract: An annular notch is provided in the body seat associated with the nozzle valve of an ALCO-type diesel injector. The notch extends from (i) an upper edge that is on the seat and is above the imaginary edge that would have been the sac inlet edge had the notch not been provided to (ii) a lower edge below such imaginary edge. The notch has a lowest wall that, at least at the portion of its length where such lowest wall approaches such lower edge, has a given angle-to-vertical of less than 60°.

Abstract: An EMD-type injector is provided with a spring seat in which the juncture between the head and the stem of the spring seat is formed as an undercut groove within specified shape parameters.

Abstract: A diesel injector is provided with a variable-volume flow-subtraction chamber containing a spring-loaded flow-subtraction piston. The chamber is connected to the pump chamber or related lines by passages that include a flow-subtraction control orifice. A space behind the piston is vented to fuel supply ducting that is associated with the system. A flow-subtraction control orifice controls the subtractive flow of fluid into the flow-subtraction chamber in predefined proportion to the flow of fluid through the combined nozzle orifices, such proportion being that between the cross-sectional area of the control orifice and the combined cross-sectional areas of the nozzle orifices. Such proportion of flow is maintained until the subtractive flow ends as the piston reaches a stop at its fully open position, whereupon the reduced-rate-of-injection phase ends and the main injection phase then occurs.

Abstract: A groove having a helix angle of zero or more is formed in the plunger of a diesel injector pump, the groove extending along and in association with the port-closing edge of the plunger and along at least a portion of the length of such port-closing edge. The groove interacts with the port that is associated with the port-closing edge to provide, in each of a succession of plunger strokes, initial fuel injection at feed rates lower than those which would obtain in the absence of the groove but without any loss of initial injection pressure, or without substantial loss of such pressure.

Abstract: A diesel unit injector of the END type is provided with a sac whose center of volume is located below the center of radius of the sac bottom. The bottom-most parts of the annular cavity which is above the seat for the nozzle valve are shaped to provide compensatory structural reinforcement.

Abstract: A diesel fuel injector is provided with a secondary spill aperture operable to increase to a maximum value and then decrease to zero during an early part of the injection portion of the stroke of the injector pump plunger in a manner to maintain injection pressure at relatively high levels at the beginning of such injection portion of the plunger stroke whereas the rate of injection is lower during such early part of such injection portion than it would be in the absence of said secondary spill aperture.

Abstract: The conical nozzle valve seat of a diesel injection nozzle is shaped to form a notch extending down from an annular upper notch boundary on the bottom face (seat) of the valve. The notch boundary is of a greater diameter than the annular entry edge of the sac and the minimum cross-sectional flow area of the valve is greater than that associated with an otherwise identical valve that does not have such annular notching.

Abstract: A diesel unit injector of the EMD type is provided with a tip whose radius is centered below the center of radius of the sac which it encloses, and the sac volume is minimized. The lower face of the nozzle body of the injector is faired in such a manner as to maintain a strong wall cross-section. A system utilizing a set of potential substitute spring seats is used to reset the opening pressure, as upon rebuilding, within narrow tolerances. The nozzle body is shortened and the check valve cage correspondingly lengthened to reduce the length of the injector valve proper. Trapped volume is reduced consistently with fuel flow requirements.

Abstract: A fuel injection nozzle of the outwardly opening poppet pintle type for use with internal combustion engines is provided which is economical to fabricate, assemble and recondition and which, at the same time, is capable of improved delivery and dispersion of fuel for optimum engine functioning even when the engine is intended to be operated at high speeds. The nozzle utilizes a nozzle holder which includes a separable holder body and holder body tip, both formed with an axial fuel passageway therethrough, and having aligned enlarged counterbores forming a chamber in which the upper end of a pintle valve is suspended by attachment to a slidable cup-shaped combination upper spring seat and valve hanger. The lower spring seat is also cup-shaped and is seated in the counterbore of the holder body tip to align the enlarged counterbores.