The aircraft in question is the "Wonga" - the solitary prototype high-wing aircraft designed and built in 1930 by Australia's first qualified aeronautical engineer, Leslie John Roberts Jones.
The aircraft was originally powered by a Curtiss, but the engine fitted in the photo is a replacement for the original Curtiss - it is a "Harkness Hornet", another Australian-design aircraft engine, produced by Harkness & Hillier in 1929.
This engine powered only two models of aircraft, the "Wonga" and the Genairco biplane. Unfortunately, the Harkness aero engine was not a commercial success.
ANU - Biography - Leslie John Roberts Jones
Ed Coates collection - VH-ULZ - the Jones "Wonga"
The Harkness Hornet aero engine