An injection molding machine having a first mold portion and a second mold portion. The second mold portion being movable relative to the first mold portion and together defining a mold cavity. The injection molding machine includes a fluid path extending through the first mold portion. The fluid path has an inlet and a radially continuous, downwardly-extending, circumferential outlet in fluid communication with the mold cavity. The injection molding machine further having a valve ring movably coupled in the first mold portion. The valve ring includes a downwardly extending rim portion substantially disposed within the fluid path. The valve ring is positionable in a closed position where the rim portion engages the circumferential outlet to obstruct flow of the molding material from the fluid path to the mold cavity and an opened position where the rim portion is spaced apart from the circumferential outlet to permit flow of the molding material from the fluid path to the mold cavity. The injection molding machine further includes a heating assembly in thermal communication with at least a portion of the fluid path to maintain the molding material in an uncured state for thermoset rubbers and plastics, and in a molten state for thermoplastics.