The first Austro-Daimler six-cylinder engine was designed by Dr-Ing Ferdinand Porsche to be an aircraft engine from the outset. Of high quality manufacture the Austro-Daimler was modestly rated at relatively low rpm, which gave the engine family a reputation for robustness and reliability.
Features of the Austro-Daimler included welded steel water jackets, (originally copper), seven main bearings and large diameter inclined inlet and exhaust valves opened by dual action push-pull rods and closed by spring pressure.
The Austro-Daimler inspired many imitators such as the Mercedes D.II, Benz Bz.IV, Beardmore, and Hiero 6. Modest availability of the Austro-Daimler engines forced some aircraft manufacturers to substitute Mercedes (the German Daimler company) engines in their aircraft, due to greater availability.