From the markings on this artifact, it was built by the Warner Aircraft Corporation of Detroit, Michigan, but designed by Ole Fahlin. Warner built four models of similar radial air-cooled engines. The company existed from 1927 until 1950 when its assets were sold to the Clinton Machine Corporation.
Ole Fahlin was a Swedish born aviation enthusiast who learned to fly in Germany, was a pilot in the Swedish Royal Air service, and came to the U.S. following World War I. Frustrated with the propeller on a surplus Curtiss Jenny he barnstormed with in the Midwest U.S., he designed his own and achieved improved performance. With a well-known reputation as a propeller designer, he began a manufacturing business in Minnesota. He later moved the company to Marshall, Missouri when offered a larger property allowing greater production during World War II. He moved to California in 1962 where he later consulted for Lockheed Aircraft.
This object is not on display at the National Air and Space Museum. It is either on loan or in storage.