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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.

Piston is a critical component of the engine as it exposed to high inertial and thermal loads. With the advent of high performance engines, the requirement of the piston to perform in extreme conditions have become quintessential. Piston scuffing is a common engine problem where there is a significant material loss at the piston and the liner, which could drastically affect the performance and the longevity of the components. This detrimental phenomenon would occur if the piston is not properly designed taking into consideration the thermal and structural intricacies of the engine. A water-cooled gasoline engine which had significant wear pattern on its piston skirt and liner was considered for this study. The engine block was made of aluminum alloy with a cast iron sleeve acting as liner. The piston-liner system was simulated through a commercially available numerical code which could capture the piston's primary and secondary motion.

An inadequate sealing of the combustion chamber gasket interface may have severe consequences on both the performance & emission of an engine. In this investigation, both the distribution of the contact pressure on the gasket and the stresses of the cylinder head at different loading conditions are explored and improved by modifying the design. A single cylinder gasoline engine cylinder head assembly has been analyzed by means of an uncoupled FEM simulation to find the sealing pressure of the multi-layer steel (MLS) gasket, strength & deformation of the components involved. The thermal loads are computed separately from CFD simulations of cylinder head assembly. The cylinder head assembly consisting of head, blocks, liner, cam shaft holder, bolts, gaskets, valve guides & valve seats, is one of the most complicated sub-assembly of an IC engine.

Engine designers today are faced with two paramount obstacles viz. rising demand for fuel efficient vehicles and stricter emission control norms. In this regard, the piston liner interface is a very important part of the engine, as it is the source of almost half of the frictional loss of an engine and defines the blowby, lubrication oil consumption and to some extent influences the hydrocarbon emission. A single cylinder 4-stroke 110cc gasoline engine is taken up for study. A commercially available numerical code is used to simulate the piston and ring dynamics of the engine. The analytical FMEP results are correlated with the experimental FMEP found out by conducting a tear down motoring test on the engine. The blowby of the simulation model is validated with experimentally measured value of the fired engine. The effect of bore clearance and design of the piston rings on friction, oil consumption and blowby is studied.