Rolls-Royce Phantom 1
Phantom I. 1925 – 1929
The replacement for the Silver Ghost was initially called the New Phantom, but became known as the Phantom I after the introduction of the Phantom II. A little larger and naturally more modern car than its predecessor, the chassis and engine design were similar to the Ghost but with a detachable cylinder head. This was equipped with pushrod-operated overhead valves. The gearbox remained a separate unit but now with a plate clutch instead of the earlier cone type.
Production numbers: 2212
Technical Specification
Engine: 6 cylinders, capacity 7668cc. Pushrod-operated overhead valves. Twin cylinder blocks on an aluminium 2–piece crankcase. 7 bearing crankshaft with vibration damper. Single detachable 12-plug cylinder head, initially cast iron (CR 4:1) with all plugs on the nearside; aluminium from 1928 with 6 plugs per side (CR 4.2:1). Pressure fed lubrication by gear type pump. Oil capacity 12 pints.
Carburation: R-R 2-jet type with automatic air valve and starting carburettor.
Ignition: Independent magneto and coil, each firing 6 plugs.
Cooling system: Vertical radiator shutters operated by hand. Fan and centrifugal water pump.
Fuel system: 18-gallon rear tank and Autovac. Direct-acting gauge on tank superseded in 1927 by a Hobson Teleguage on the dashboard.
Transmission: Separate unit 4-speed gearbox with a single plate clutch. Torque tube. Right hand gearchange. Rear axle ratio 3.47:1 (from 1927 optional 3.25:1)
Suspension: Leaf springs. Semi- elliptic front and cantilever rear. Friction shock absorbers initially, changed to hydraulic at the front 1926 and the rear 1927.
Brakes: Internal expanding 4–wheel operation with independent handbrake on the rear wheels. Mechanical servo driven from the gearbox.
Steering box: Worm and nut.
Chassis lubrication: By oil gun.
