Piaggio & C. Soc. An.-Genoa, Italy 1933
The engine company Piaggio serially produces engines P VII, P IX, P X, P XI, P XII, P XVI, P XIX, all water cooled star models. On the beginning, the production of Piaggio aeronautic engines was mainly based on the growth of projects born thanks to the technical co-operation with the French company Gnome-Rhône. In fact the Italian engine company had purchased by Gnome-Rhône, more than an actual licence, the right to copy matters it thought as suitable. This right was similar to the one that in due time Gnome had made with the British engine company Bristol for Jupiter engines. The model Stella P IX R, a 9 cylinder model (cylinders are star arranged) is derived from Gnome-Rhône 9K, made in 3 versions, the last of which had a 2-speed compressor and a reducing unit.
The engine was largely used by the Italian Air Forces for bombers and scouts, manufactured between 1935 and 1940. The Piaggio Stella P IX R, complete with reducing unit, was mainly installed on seaplanes Fiat MF 4.