In 1934, the Japanese Navy began development of an 18-cylinder, W-type engine known as the 671 kW (900 shp) Model 94, likely a derivative of the French Lorraine aircraft engine. Later, more powerful versions of this engine were undertaken, including the YE2A, which started development around 1937-38.
The YE2A was designed for remote installation within an aircraft fuselage, the purpose being aircraft streamlining and speed. Designed for a pusher installation, the engine was experimentally tested, but probably never test flown.
This Nakajima engine resembles the YE2A, but was designed for tractor installation. It also resembles a version of a Hispano-Suiza engine, which had been studied by the Yokosuka Naval Air Arsenal. Mitsubishi had acquired a license in 1935 for Hispano-Suiza engines, further suggesting how the Japanese might have acquired these engines. The intended airframe application for the engine is unknown.
Along with other Japanese engines, this artifact was collected for the purpose of technical evaluation.
This object is not on display at the National Air and Space Museum. It is either on loan or in storage.