A method for forming a rotor for an induction motor includes providing a rotor core including a plurality of conductor bar grooves having first and second ends corresponding to first and second ends of the rotor core wherein the conductor bar grooves are progressively larger closer to the ends of the conductor bar grooves. The rotor core is placed into a casting mold, and molten metal is introduced into a first end of the casting mold. The molten metal flows from the first end of the casting mold through the plurality of conductor bar grooves to a second end of the casting mold. The molten metal solidifies to form conductor bars in the plurality of conductor bar grooves and to form shorting rings across exterior portions of the end elements within the first and second ends of the casting mold.