Process parameters of lost foam casting were studied experimentally on a commercial scale for two casting techniques: conventional and vacuum assisted gravity castings. The paper presents the results of the foundry experiments focused on the time and spatial dependent aspects of mold filling of a commercial pattern (Disconnect). A small-scale commercial model was designed and fabricated to conduct the experiments to study the thermo- and hydrodynamics of the mold filling characteristics. A high sensitivity linear output capacitive sensor was used to record the rate of sand flow and compaction in flask while horizontal and/or vertical vibrations were applied. A computer aided thermometric technique was used to study the heat-related processes in the counter-gravity lost foam vacuum casting. A complete pattern of vacuum/pressure fluctuations is obtained during counter-gravity vacuum casting using bi-directional vacuum/pressure transducer. Tolerance analyses were performed for styrofoam patterns and their cast products produced by the conventional and vacuum assisted casting procedures.