The primary input needed for engine performance, mechanical design analysis and combustion evaluation is the dynamic cylinder pressure data. The development of an engine analyzer is herein presented. The system is based on a PC, a 500,000 samples per second A to D data acquisition system, and EngineTech Series of software. Both combustion performance and mechanical analysis can be evaluated while the engine is running. Features and assumptions used in cycle analysis and combustion software are discussed, and the available functions and results are described in this paper.