FIELD: mechanical engineering; internal combustion engines. SUBSTANCE: according to proposed method working charge is taken into engine delivery cylinder, is compressed and then bypassed into combustion chamber for combustion in constant volume with subsequent expansion of combustion products in engine expanding cylinder and discharge of exhaust gases. Compressed charge is passed into heat-insulated combustion chamber formed by piston, head and walls of expanding cylinder. Combustion of fuel takes place when piston of expanding cylinder stops in top dead center. Compression ratio, volume of compression chamber of delivery cylinder and volume of combustion chamber of expanding cylinder are adjusted, depending on kid of fuel used and load of engine, by changing position of piston top dead centers. Invention contains description of engine implementing this method. EFFECT: increased efficiency of fuel combustion process. 6 cl, 7 dwg
