Junkers Jumo 223

The Junkers Jumo 223 was an experimental 24-cylinder aircraft engine based on the Jumo 205, and like the Jumo 205 it was an opposed-piston two-stroke diesel. It had four banks of six cylinders in a rhomboid arrangement, with four crankshafts, one at each vertex of the rhombus, and 48 pistons. It was designed for 2,500 horsepower at 4,400 rpm and weighed around 2,370 kg. Only one example is known to have been built, and it is rumoured to have been taken to Moscow at the end of the Second World War. In 1942 the 223 was abandoned in favour of the even larger Jumo 224, intended to produce 4,500 horsepower.