All Aero

A Duthiel-Chalmers six-cylinder horizontal engine of 128 mm. (5.04 in.) bore, 130 mm. (5.12 in.) stroke, and 612.84 cu. in. total displacement, was rated 72.5 h.p. at 1200 r.p.m. The dry weight was reported to be 385 lbs., or 5.3 lbs. per rated h.p.