Rolls-Royce 25/30

25/30 1936 - 1938

A development of the 20/25, the engine capacity was increased to 4 ¼ litres and for the first time the Rolls-Royce carburettor was replaced with a proprietary Solex instrument.
The 20/25 was also available for sale in 1936.

Production numbers: 1201

Technical Specifications:

Engine: 6 cylinders, capacity 4257cc. Separate cast iron block and two-piece aluminium crankcase with detachable cast iron 6-plug head, deturbulated from 1937. Overhead pushrod operated valves. 7-bearing crankshaft with vibration damper. Pressure fed lubrication with relief valve feeding rocker shaft and timing gears. Oil capacity 14 pints.

Ignition system: Coil ignition system with standby coil mounted together. Centrifugal advance with hand override.

Cooling system: Engine driven water pump and fan. Thermostatically controlled radiator shutters.

Carburation: \Stromberg downdraught carburettor with accelerator pump. Exhaust heated inlet manifold.

Fuel: 18 gallon rear tank with double SU electric fuel pumps. Electric gauge. Low fuel warning light.

Transmission: 4-speed gearbox in unit with engine. Synchromesh 3rd and top. Right hand gearchange. Clutch, Borg and Beck type. Open drive propeller shaft.

Suspension: Semi-elliptic leaf springs front and rear. Hydraulic shock dampers equipped with Ride Control.

Brakes: Internal expanding 4 – wheel operation with independent handbrake on the rear wheels. Mechanical brake servo motor driven from the gearbox.

Steering: Marles cam and roller

Chassis lubrication: ‘One-Shot’ centralised lubrication system.