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India is considered to have one of the maximum two wheeler density in the world. Hence, all the scooter and motorcycle manufacturers are striving to keep their market share by quickly bringing quality products with high mileage at a cheap price tag. As emission norms are becoming stringent day by day, these OEMs have to take care of every detail in the engine that is driving their vehicles. So today's engineers are obliged to refine and improve the technologies they use, faster and with greater accuracy than ever before. This paper focuses on reducing Cylinder Bore deformation for a two wheeler engine through CAE simulation. In standard testing conditions this deformation was observed to cause engine seizure. Bore deformation is of great significance to the overall performance of an engine. It can increase oil consumption, blowby and emissions and may influence piston dynamics to a great extent.

When a scooter is put on main stand, it keeps the vehicle from falling as it rests against the engine crankcase. As the main stand is operated it transmits a large amount of load to the crankcase, thus creating a necessity to check the durability of the later. Practical tests showed that continuous application of the main stand resulted in the failure of its pivot area on the crankcase. This raised questions not just on the feasibility of the crankcase design in terms of durability, but also on the main stand design in terms of a load transmitting member. However, as the project was at its later stage, crankcase design could not be altered; thus it asked for a main stand design optimization. The base main stand model was thus taken for MBD simulation and loads were generated for further FEA analysis. The meshed crankcase model was taken in a commercially available FEA code for checking its durability.

With ride comfort in a motorcycle gaining significance, it is important to minimize vibration levels at the customer touch points. The reciprocating piston imparts rotary motion to the crankshaft which in turn induces unbalance forces and produces vibration in the vehicle, thus influencing the ride quality. Generally, the primary inertial forces are balanced by a combination of balancer body and crank web. However, being a commuter bike, a balancer body could not be accommodated due to cost and space constraints. In such scenario, the first order unbalance force cannot be completely eliminated but can only be redistributed by adding counterweight to the crankshaft. Proper distribution of these forces is required for optimum vibration levels at motorcycle touch sensitive points (TSP) such as handle bar, footrest etc.