Modified aspirated internal combustion engine

摘要

A crankshaft eccentrically mounted to the engine block bearings of an internal combustion engine for providing improved volumetric efficiency. A modified crankshaft journal and engine block bearing structure is provided at each crankshaft support location so that the connecting rod bearings rotate about an eccentric centerline (ECL). Eccentricity is achieved by off-setting the crankshaft journals a predetermined distance above the original true centerline (TCL) of the crankshaft, preferably on the order of about one-quarter to one-half inch. The top dead center (TDC) of each piston remains the same relative to its cylinder, but the bottom dead center (BDC) of each piston relative to its cylinder is lowered by the amount of the off-set because the engine block bearings are lowered with respect to the true centerline of the crankshaft by the amount of the off-set on the crankshaft journals. The crankshaft is forged with the eccentric off-set, then is machined to provide the precise tolerance needed for fitting into the engine block bearings and is harmonically balanced as needed. The engine block bearings are enlarged over the original specification, and are lowered the same predetermined eccentric off-set distance. The crankshaft is then installed in the engine block.