Apparatus and systems relating to fuel injectors and fuel passages in gas turbine engines

A combustor casing fuel injector in a combustor of a combustion turbine engine, the combustor including a combustor casing (114) that encloses internal structure of the combustor, wherein the combustor casing fuel injector includes a fuel manifold (162) adjacent to an outer surface of the combustor casing. In certain embodiments, the combustor casing fuel injector includes a fuel injector (166); wherein the fuel injector (166) extends through the combustor casing (114) from a position within the fuel manifold (162) to a predetermined fuel injection location; and wherein the fuel injector (166) includes a protruding injector inlet (171) within the fuel manifold (162).