Leonard Wallenberg’s Szekely running on his Curtiss Wright Junior. My guess is that this would be 657v, serial 1039
Running a 1931 Szekely airplane engine at Grand Haven, Michigan airport at the EAA Chapter 211 Picnic, August 22, 2009.
1929 Szekely 3 cylinder radial air cooled airplane engine – built in Holland, Michigan. Presentation by Phil Michmerhuizen.