Sand casting is reputed for the manufacture of engine components as a result of its ease of operation.An assemblage of process parameters at optimal conditions leads to enhanced mechanical properties of automobile engine components. The Response Surface Methodology Design of experiment created an experimental layout for the sand casting process parameters and the various levels as applied in the production of engine pistons at the foundry. The Box-Behnken Design provided a matrix of 27 experiments to be conducted. Multiple linear Regression technique was employed to develop a mathematical model for the hardness of the aluminium alloy. The developed model was inputted into the evolutionary Genetic Algorithm tool box as an objective model. The optimal levels determined from the Genetic algorithm were used to carry out actual experiment in the foundry and the result was similar to the predicted hardness value of the developed model. Statistical ANOVA test conducted showed that the mathematical model was adequate with a R 2 value of 81.02% and R 2 (adjusted) value of 60.07%. The developed model has a p-value of 0.016 which indicates that the model was significant. The optimal values obtained for pouring temperature, vibration frequency, vibration time and runner size are 700 o C, 31.52Hz, 59.998sec and 469.69mm 2 respectively.

Piston is an important internal combustion engine component that works with other engine components to withstand severe stresses and high temperature that are generated in the combustion chambers. Pistons are subjected to a very high mechanical and thermal load which results from extreme pressure cycles and huge forces of inertia caused by extremely high acceleration during the reciprocating motion. The 0.67hp generator piston designed had the values of parameters to be: 51.00mm Piston stroke; 48.85mm piston bore diameter; 3.66kw brake power; 4.87kw indicated power; 11.63Nm engine torque; 3.22mm piston thickness and 9.44cm3 clearance volume. The piston parameter values calculated were found to be in accordance with the recommended range of values in the design and operating data for internal combustion engines. Keywords: Piston design, machine parameters and internal combustion engines.

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A profound engineering design and modeling of fatigue strength machine for testing the failure which occurs when a metallic material is subjected to cyclic stresses is presented. The main goal is developing a locally made fatigue strength machine that can be used in material science laboratory. A major direction in this development of the machine is the ability to thread on the path of technology transfer and dominance by concentrating on the building of indigenous capacity. In carrying out the machine development, engineering design formulae were applied and Computer Aided Design modeling was developed. The developed fatigue strength testing machine had a designed machine capacity of 18875Nmm that sustained a motor power of 5.93kw.The machine shaft diameter determined to be 9.88mm developed an equivalent torque and bending moment of 45799.8Nmm and 40890Nmm respectively. The machine designed critical speed of 23.52rad/s had belt tensions on the tight and slack sides to be 139.02N and 44.65N respectively. The fabricated machine has the ability to record low and high fatigue cycles.