This report provides an update on axial engines with variable compression ratios, since a previous report at FISITA 1974. Details are provided on bench tests conducted on a modified Renault. Fuel utilized was of two extremes of octane, ordinary gasoline of low octane, and methanol.Test results were satisfactory under various compression ratios from 7.5/1 to 9/1. There were no starting or idling problems. Plans are now underway for the development of a prototype engine, with a simplified construction.Studies are also planned on diesel engine and Stirling engine applications.