@@elvispresley4649 This model is a liquid-cooled to air-cooled engine conversion model of the Type 3 fighter “Hien”. Although a slight reduction in maximum speed was observed due to the increase in air resistance caused by the conversion of the engine, the power output was improved, resulting in an increase in operational speed in actual combat, and the stability of the aircraft was dramatically improved due to the familiar air-cooled engine. Excerpt from Japanese Wikipedia