Pattern for the lost foam casting process including a pouring-basin-forming portion, a sprue-forming portion, a runner-forming portion, a gate-forming portion, and an inline-riser-forming portion. The runners formed by the pattern each have an inline riser through which melt flows between an inlet to and outlet from the riser during pouring, and in which melt is stored to feed the casting with melt during cooling/shrinkage of the casting. A sand dam surrounds the mouth of each gate and traps particulates from a liquid styrene layer that precedes the melt front in the riser.