A fuel injector includes an injector housing defining a longitudinal axis, and including a body piece having formed therein a fuel inlet defining a transverse axis intersecting the longitudinal axis. The injector housing further includes a nozzle having formed therein a plurality of spray outlets, and including a nozzle terminal tip. The injector housing further includes a locating surface axially inward of the nozzle terminal tip and extending circumferentially around the nozzle. A first axial distance (AD) is defined between an intersection of the transverse axis and the longitudinal axis, and the nozzle terminal tip. An exposed tip length axial distance (TL) is defined between the locating surface and the nozzle terminal tip. A ratio of AD to TL is from 8.06 to 8.34.

A fuel injector includes an injector housing having a fuel connector, and an outer housing surface extending around a longitudinal axis of the injector housing. The outer housing surface includes a cylindrical upper section, a cylindrical lower section, and a middle section. The fuel connector defines a connector axis oriented normal to a longitudinal axis of the injector housing and extending between a first connector end attached to the middle section, and a terminal connector end radially outward of the outer housing surface and having therein a fuel inlet. The fuel connector includes an outer connector surface having an unthreaded base section, and an externally threaded end section adjacent to the terminal connector end.

A fuel injector includes an injector housing having a fuel connector, and an outer housing surface extending around a longitudinal axis of the injector housing. The outer housing surface includes a cylindrical upper section, a cylindrical lower section, and a middle section. The fuel connector defines a connector axis oriented normal to a longitudinal axis of the injector housing and extending between a first connector end attached to the middle section, and a terminal connector end radially outward of the outer housing surface and having therein a fuel inlet. The fuel connector includes an outer connector surface having an unthreaded base section, and an externally threaded end section adjacent to the terminal connector end.

A fuel injector includes an injector housing defining a longitudinal axis extending between a first axial injector end and a second axial injector end. The injector housing includes an upper body piece forming the first axial injector end and including a fuel connector defining a connector axis intersecting the longitudinal axis. The injector housing further includes a nozzle having formed therein a plurality of spray outlets, and including a nozzle terminal tip. An injector full diameter (FD) is defined by the upper body piece. An axial distance (AD) is defined between an intersection of the connector axis and the longitudinal axis, and the nozzle terminal tip. A ratio of AD to FD is from 4.8 to 5.1.

A fuel injector includes an injector housing defining a longitudinal axis extending between a first axial injector end and a second axial injector end. The injector housing includes an upper body piece forming the first axial injector end and including a fuel connector defining a connector axis intersecting the longitudinal axis. The injector housing further includes a nozzle having formed therein a plurality of spray outlets, and including a nozzle terminal tip. An injector full diameter (FD) is defined by the upper body piece. An axial distance (AD) is defined between an intersection of the connector axis and the longitudinal axis, and the nozzle terminal tip. A ratio of AD to FD is from 4.8 to 5.1.

Systems and methods regarding a ducted fuel injection (DFI) combustion system for an internal combustion engine can control an injection timing of a fuel injector to output fuel injections through at least one duct and into a combustion chamber of the internal combustion engine. The injection timing can include one or more pilot injections according to a predetermined range before top dead center (BTDC) for a combustion cycle; and a main injection into the combustion chamber for the combustion cycle after all of the one or more pilot injections. A first amount of the fuel injected for the main injection can be greater than a second amount of fuel injected for the one or more pilot injections. The predetermined range before top dead center (BTDC) of the one or more pilot injections can be from 85 to 40 degrees BTDC.

Apparatuses for immobilizing fuel injection apparatuses are disclosed. A coupling member couples a fuel injection apparatus with an injector body of an engine. The coupling member includes a top surface, a bottom surface, a side surface, and an opening extending from the top surface to the bottom surface. The opening receives the fuel injection apparatus. The coupling member also includes a protruding portion extending from the bottom surface or the side surface which comes into contact with the injector body to prevent rotational movement of the fuel injection apparatus.

Apparatuses for immobilizing fuel injection apparatuses are disclosed. A coupling member couples a fuel injection apparatus with an injector body of an engine. The coupling member includes a top surface, a bottom surface, a side surface, and an opening extending from the top surface to the bottom surface. The opening receives the fuel injection apparatus. The coupling member also includes a protruding portion extending from the bottom surface or the side surface which comes into contact with the injector body to prevent rotational movement of the fuel injection apparatus.

Methods and systems are provided for a fuel injector of an internal combustion engine. In one example, a fuel injector includes a body having a flange shaped to seat within a shoulder of a passage of a cylinder head. The shoulder is positioned at an inner side of the cylinder head such that the fuel injector is coupled to the cylinder head at the inner side by the flange.

Methods and systems are provided for a fuel injector of an internal combustion engine. In one example, a fuel injector includes a body having a flange shaped to seat within a shoulder of a passage of a cylinder head. The shoulder is positioned at an inner side of the cylinder head such that the fuel injector is coupled to the cylinder head at the inner side by the flange.