HOW MAD IS THIS?!

[Greybeard]

The Napier Nomad stands out as possibly the most complex aircraft engine ever constructed. It combines a two-stroke diesel with a gas turbine. The Nomad is what's known as a turbo-compound engine, which extracts unused energy from exhaust gasses with a turbine. Via a mechanical link, the turbine sends this energy back to the engine's crankshaft to be used for work. While this can increase power, Napier's engineers were more interested in improving efficiency. By reducing the amount of energy wasted through the exhaust, less fuel was needed to achieve the same output. This helped to increase range. It made 4,000 hp, but the engine was competing with jet engines and there was no interest in it. This example is located at the Smithsonian National Air and Space Museum. https://planehistoria.com/napier-nomad/