Abstract: Disclosed is a mold for casting multiple castings in sand including a flaskless mold and a core assembly. The core assembly is within the flaskless mold with the sand surrounding the core assembly. The core assembly can have a central axis, a plurality of window cores and at least two splitter cores. The plurality of window cores and the at least two splitter cores are alternately stacked to form a plurality of casting cavities along the central axis. In some instances, two of the plurality of window cores are mirror-image oriented with respect to each other along the central axis and two of the plurality of window cores are oriented the same with respect to each other along the central axis.