Casting simulation has become a powerful tool to visualize mold arrangements, filling, solidification and cooling, and to predict the location of internal defects such as sand inclusion, shrinkage porosity, and cold shuts. It can be used for avoid existing casting process defects, and for developing new castings without shop floor trials. With the help of simulation efficiency and quality of casting product is improving. It needs only planning, accuracy, and quality of knowledge for simulation. The simulation of chilled cast iron tappet depends on factors like Carbon, Silicon, Manganese, and pouring temperature. These factors help in improvising the mechanical strength of tappet. MAGMASoft5.2 is used for simulation based on parameters i.e. C-3.2 to 3.6, Mn-0.4 to 0.7, Si-2.0 to 2.4 and T-1450°C to 1550 °C. These factors improve the chilled depth value during phase transformation. © 2006-2016 Asian Research Publishing Network (ARPN).