Introduced in 1929 as the successor to the New Phantom, retrospectively known as the Phantom I, the Phantom II marked a significant evolution with deliveries commencing in September of that year. Diverging from its predecessor, which inherited its underpinnings from the preceding 40/50hp model, the Silver Ghost, the Phantom II featured an entirely new chassis.
Available in two wheelbase lengths—144″ and 150″—the new low-slung frame, with a radiator set well back, provided a platform for coachbuilders to craft sleeker, more modern designs compared to the upright styles of the past.
Extensive revisions were made to the engine as well. While maintaining the Phantom I’s cylinder dimensions and basic layout, which included two blocks of three cylinders with a common aluminum cylinder head, the combustion chambers underwent redesign. The cylinder head transitioned to a cross-flow type, featuring inlet and exhaust manifolds on opposite sides.
The magneto/coil dual ignition system, consistent with the Phantom I, was retained. These engine modifications resulted in a substantial improvement in performance, showcasing the Phantom II’s enhanced capabilities. 
Source: Bonhams Cars
