A roller lifter for an internal combustion engine includes a cylindrical lifter body having a first end, a second end and a roller rotatably attached to the first end. The first end has a first diameter and the second end has a second diameter greater than the first diameter and a flat surface configured to engage a corresponding flat surface on an adjacent roller lifter and to prevent axial rotation of the roller lifter while in use. The roller lifter may further include a recess extending along a longitudinal axis from the second end toward the first end.