Effect on the Performance of a Small Air-Cooled Compression-Ignition Engine of Variations in the Ambient Atmospheric Conditions

In this paper consideration is given to the effect upon the performance of small compression-ignition engines of variations in ambient atmospheric conditions. The validity of some correction and derating formulae when applied to such engines is discussed, and an experimental investigation is described in which two small air-cooled compression-ignition engines were run at constant speed in atmospheric conditions which could be controlled at values ranging from the normal to those widely different from normal conditions. Some conclusions relating to corrections for deviation from standard conditions are drawn from these test results and a comparison is given of the correction of experimental results by a number of correction or derating formulae, which are described in Appendix I