The R 1340 also has a circle of 9 cylinders, but they are considerably elongated by comparison and there is no 2nd row.
These are the WWII airplanes which could have carried that kind of engine:
Convair CV-240 family
Curtiss C-46 Commando
Interesting to see how the safety wiring has held up after so many years!
Edited by Bluehawk, 16 December 2010 - 04:56 PM.