The molten metal injector system includes a holder furnace containing a supply of molten metal. A casting mold is supported above the holder furnace. The mold defines a mold cavity for receiving molten metal from the holder furnace. One or more molten metal injectors is supported from the bottom side of the mold. The injector is in fluid communication with the mold cavity and includes a reciprocating piston for pumping molten metal upward from the holder furnace and injecting the molten metal into the mold cavity. The injector is partially submerged in molten metal when the holder furnace contains molten metal. The injector includes a molten metal intake for receiving molten metal into the injector. The molten metal intake is located below the surface of the molten metal in the holder furnace.
 The subject matter of this application was made with United States government support under Contract No. 86X-SU545C awarded by the Department of Energy. The United States government has certain rights to this invention.