A Brief History of the Italian Marque
Italian engineer Vincenzo Azzariti anticipated Ducati with his desmodromic 173cc OHC single of 1930, developed for Benelli who housed it in a prototype.
This was followed in 1934 by a 348cc bevel-drive DOHC desmo 350 twin with 360 degree crank. This remarkable engine had a bore and stroke of 62 x 57 mm and displaced 344cc.
Sources: Henshaw, desmodromology.nl, MC Storico Conti