It was a step too far, and too late for the Japanese. The Ki-83 was powered by 2 x 18 cyl Mitsubishi Ha 43 Model 11 engines (Ha 211 Ru), each producing 2,200HP. The engine was fuel injected, fan cooled and turbo-supercharged.
But the engine was new, and unproven, and when put into operation, it was unreliable. It would've taken another year or two to get the engine even moderately reliable, and even then it was an enormously complex engine.
The aircraft itself shows a lot of similarities to a Mosquito in its aerodynamics and profile.
Mitsubishi Ha 43 Model 11 (Ha 211 Ru), Radial 18 Engine | National Air and Space Museum
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Type: Reciprocating, 18 cylinders, 2 rows, radial, air-cooled, turbosuperchargedPower rating: 1,641 kW (2,200 hp) at 2,900 rpmDisplacement: 41.7 L (2,546 cu in.)Bore and Stroke: 140 mm (5.5...