An unusual cylinder layout: a multi-row radial engine, where inline cylinder banks are shared between rows. Many of these engines are liquid-cooled, which is otherwise rare and difficult to achieve for the usual radial engine, with staggered banks.
Many of these engines are liquid-cooled, which is rare and difficult to achieve satisfactorily for radial engine. Air-cooled multi-bank engines, such as the Armstrong-Siddeley Hyena and Deerhound had difficulties cooling the rear cylinders of each bank.