Falcon II (Rolls-Royce 190 hp Mk II) (1917), 253 hp, carburettor size increased. 250 built at Derby. Falcon III (Rolls-Royce 190 hp Mk III) (1917-1927), 285 hp, increased compression ratio (5.3:1), twin carburettors replaced with four Rolls-Royce/Claudel-Hobson units.