Abstract: The forming of a wax or sacrificial pattern for investment castings in which the interior ceramic reinforced passageway forming elements are reinforced with a metallic wire, and sheathed in a quartz material is disclosed. Thereafter the wire and quartz serve as a reinforced core around which the ceramic is molded to the configuration of the passageway, and in addition containing the positioning elements for mating engagement with the wax injection die at each end of the passage forming part. The method of forming the pattern for injection molding involves the steps of first determining the passage locations, and thereafter forming a reinforced passage ceramic forming member to be positioned interiorly of the pattern. The wax injection die is formed with mating elements to support the ceramic passage forming members. Thereafter the mold is filled with sequential layers of ceramic, and fired.