Abstract: A cast piston having a metal insert that includes a cooling gallery and defines a piston ring groove. The piston insert includes an annular base having an annular cavity formed therein and an annular ring which extends radially outward from the base. A cast piston is fabricated by positioning the piston insert in a piston mold and casting a piston. After the piston is cast, the piston groove ring is machined in a portion of the annular ring and at least one channel is formed between the annular cavity and a bottom portion of the piston. In use, a cooling fluid is directed through the at least one channel and into the annular cavity.