The engine cowling used for the 1350-1500 hp series of italian radials, or the later 1700 hp series (that of the Cant Z-1018 were two Alfa Romeo 135 RC.32, but the Piaggio P.XII RC35 of the Cant 1015 posted below have an almost identical cowling) is very interesting to me. It seems that, despite the increase of power, they requires much less cooling respect to the early 850-1000 hp series, whit a great aerodynamic advantage.
It could be intresting to see an IMAM RO-57, like that of my signature, equipped with them.