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. ==Variants==