Paper Tiger
Sorry to disillusion you but US engines are designated by capacity and type
P& W R-985- is a Pratt&Whitney Radial of 985 cu.ins capacity. It is also a single - row 9 cylinder.
A Wright R3350 is an 18 cylinder Radial of 3350 cu.ins capacity.double -row(2 x 9).
A Packard V-1650 is a licence built Merlin.
A P&W R-4360 IS A 28 CYL, 4- row radial( 4x7).
The USA system for designating engines is based around capacity,whereas our system is more HP based,and capacity in litres.(conversion factor for cu.ins - ltrs = x16.38)
As a guess you can probably guesstimate the number of cylinders by dividing capacity by 110 for small engines and 140-155 for larger one s.
Lu Z will probably to put me straight if i`m talking bO*****S.
