Method and apparatus for determining the compression ratio of an engine cylinder

摘要

A method of determining the compression ratio of a cylinder of an internal combustion engine. While the engine is being driven by a prime mover a PV curve is developed which is stored in the memory of a microprocessor. The unswept volume of the cylinder is determined by trying various values of unswept volume in the function PVn=C and determining which value of unswept volume causes the curve developed by this function to best fit the stored curve. Compression ratio is determined after the unswept volume is determined.