Junkers Jumo 223
The Junkers Jumo 223 was an experimental 24-cylinder aircraft engine based on the Junkers Jumo 205. Like the Jumo 205, it was an opposed piston two-stroke diesel engine. It had four banks of six cylinders in a rhomboid configuration, with four crankshafts one at each vertex of the rhombus, and 48 pistons. It was designed for a power of 2,500 horsepower at 4,400 rpm, and weighed around 2,370 kg.
In 1942 the 223 was abandoned in favour of an even larger engine, the Jumo 224 with an intended output power of 4,500 horsepower.