A rotary needle fuel injector having a housing including a wall having a plurality of non-circular apertures extending through the wall and a rotatable rod inside the housing and having a bore through which fuel is supplied. The rotatable rod has a plurality of apertures communicating with the bore and in selective communication with the non-circular apertures in the housing wall. The non-circular apertures also include an axis of symmetry extending along a direction of rotation of the rotatable rod and an axis of asymmetry perpendicular to the axis of symmetry.