Relation of motion resistance torque and friction torque in the four stroke engine

Friction resistance identification is indispensable to determine the results of engine modifications which goal was to improve the engine mechanical efficiency. Unfortunately measurement of the friction torque is very difficult to realize because in the total motion resistance torque of the combustion engine the friction torque is only a small part. Resistance torque connected with compression of working medium and also at higher engine speeds with inertia resistance is much higher than friction torque. As a result of research made on the engine test bed the course of resistance connected with realization of the thermodynamic cycle were defined. Sufficient accuracy of these courses allows making an attempt to evolve friction resistance signal from global resistance signal. In the paper comparison of the total motion resistance with results of friction resistance computer simulations for hydrodynamic lubrication of piston-cylinder liner kinematic assembly will be made. It is worth to emphasize that movement resistance researches were made at the serial engine with only slight modifications, which considerably restricts the possibility of diversified engine working conditions influence in relation to the actual engine. Further researches on complete movement resistance simulation of the combustion engine are intended to be realized in order to determine the realizability and probable range of desirable friction losses reduction. Promising results will allow designing the competitive engine relative to present tendencies of "ECOMATIC" engine operation system which was proposed for the first time by Volskswagen.