 With a production run of at least 900 engines, the most-produced aviation diesel engine in history was probably the Junkers Jumo 205.Similar developments from the Junkers Motorenwerke and licence-built versions of the Jumo 204 and Jumo 205, boosted German diesel aero-engine production to at least 1000 examples, the vast majority of which were liquid-cooled, opposed-piston, two-stroke engines.In the Soviet Union significant progress towards practical diesel aero-engines was made by the TsIAM ("Tsentral'nyy Institut Aviatsionnovo Motorostroyeniya" – central institute of aviation motors) and particularly by A.D. Charomskiy, who nursed the Charomskiy ACh-30 into production and limited operational use.