This engine by Rudolf Diesel was completed in 1897 and is considered the first diesel engine.
The construction of this engine was preceded by two test engines in 1892/93 and 1894, which, however, did not work satisfactorily. Acceptance tests in February 1897 showed that the diesel engine now had a good level of efficiency: the fuel consumption for the horsepower-hour was 238 g, which means that 26.2 per cent of the heat contained in the fuel was converted into useful work. Soon after, the same engine achieved an efficiency of 27 percent. Even today, the diesel engine is the combustion engine with the most favourable efficiency. (Source: Allwang 2012)
1 cylinder, four-stroke, water cooling, air injection of fuel
power output: 14.7 kW (20 hp)
speed: 172 min-1
displacement: 19.6 l
bore: 250 mm
stroke: 400 mm