Green sand molding is the process used to make LS3 crankshaft molds. In simple terms, sand and water comprise the mold material. The actual recipe is more complex. The green sand’s ingredients include Western and Southern Bentanite clay, cob flour, water, and sea coal, which serves as a repellent to prevent 2,600-degree metal from penetrating the sand grains. Green sand isn’t really colored green; rather, like green wood, it gets its name because it’s wet.