Selection of a powerplant was dictated by the Japanese Navy which requested that Aichi design the aircraft around the 1,360 kW (1,825 hp) Nakajima NK9C "Homare" 12 18-cylinder two-row air-cooled radial engine. This was expected to become the Navy's standard aircraft engine in the 1,340 kW (1,800 hp) to 1,641 kW (2,200 hp) range. One production model B7A2 was later fitted with a 1,491 kW (2,000 hp) Nakajima "Homare" 23 radial engine and plans were also made to fit the 1,641 kW (2,200 hp) Mitsubishi MK9 radial to an advanced version of the "Ryusei" (designated B7A3 "Ryusei Kai") but the latter effort never came to fruition.