 At 1,260 mm in diameter, the Ha-41 was 126 mm larger in diameter than the 1,144 mm Nakajima Sakae (used in the Mitsubishi A6M "Zero" and Nakajima Ki-43 "Hayabusa").However, the Sakae was only 27.8L in displacement and 1,000 hp, while the Ha-41 was 37.5L and made 1,260 hp (1,440 in the later Ha-109 version).In any case, since the Sakae wasn't powerful enough, the only alternative available was the Mitsubishi Kinsei, which was slightly smaller than the Ha-41 in diameter, five liters smaller in displacement, and was less powerful.