FIELD: mechanical engineering; internal combustion engines. SUBSTANCE: pyramidal two cylinder piston is used in internal combustion engine. Working piston has reduced diameter and is placed in cylinder of reduced working volume, half of which is less than volume of combustion chamber. Engine uses for its operation a new method of compression of air-fuel mixture and high pressure hot gases. According to this method, compression of air-fuel mixture in combustion chamber is provided by compressor and by working piston located in cylinder with working volume half of which is less than volume of combustion chamber, and high-pressure hot gases act onto working piston in reduced diameter cylinder with working volume half of which is less than volume of combustion chamber. EFFECT: provision of fuel economy. 2 cl, 2 dwg
