The objective of this thesis investigation was to design an experiment to investigate superheat effect on gate velocities pressurized and unpressurized gating system each having two gates, and to analyze statistically any interrelationship between these variables in CO₂ molds. A discussion on metal flow through different parts of a gating system, with a minimum of turbulence and gas aspiration, and a discussion of hydrodynamic principles relating to gating systems were given. The realization of these conditions is desirable because it results in improved casting, fewer rejects, and greater economy in a casting production. This was followed by a discussion on metal flow variables. Principle and use of instrumentation used in the experiment was discussed. Split-split-plot type of statistical design was used. Statistical analysis of results were made. The author concluded that, the type of gating system (pressurized or unpressurized) and individual gate location have significant effect, whereas superheat (100-300°F.) has no significant effect on gate velocities of aluminum - 12 percent silicon in CO₂ molds. Also, all the there variables are independent of each other. / Master of Science