Variable mass crankshaft for general car performance improvement: acceleration, fuel economy and emissions

A passenger car variable mass crankshaft is here reported. This particular device consists of an auxiliary flywheel with a high moment of inertia. It spins freely at above 1500 rpm, thanks to centrifugal masses which disengaged it from the crankshaft. The flywheel is connected once again to the crankshaft, when the engine speed reduces to under 1400 rpm. In this way, the mass of the crankshaft is increase at low engine speed (e.g. idle condition) and the magnitude of rotational fluctuations are consequently lowered. On the contrary, the extra mass is unnecessary and undesirable above certain engine speed and is therefore reduced, so improving both the vehicle acceleration, engine braking performance and fuel economy. He variable mass crankshaft device has been mounted onto a passenger car, in order to determine fuel consumption and acceleration performance, both though theoretical investigations and by means of experimental tests on roller-type bench.