The Rolls-Royce 25/30 HP Wraith Sedan by Park Ward & Co from 1939, 4257 cc, max. speed 121 km/h

The Rolls-Royce 25/30 built between 1936 and 1938 is an updated version of the 20/25 with larger engine to provide more power, as over-large bodies had often been fitted to the earlier model leading to complaints about its performance.

The in-line 6-cylinder, overhead-valve 25/30 hp engine is similar to that used in the 20/25 but increased in capacity to 4,257 cc (259.8 cu in) by increasing the bore from 3.25 inches (8.3 cm) to 3.5 inches (8.9 cm), with the stroke remaining at 4.5 inches (114.3 mm).

The compression ratio is 6:1. A single proprietary Stromberg downdraught carburettor replaced the Rolls-Royce one, and magneto ignition was no longer fitted, but a standby coil was provided.

The four-speed gearbox is mounted in unit with the engine, and a traditional right-hand change used. Synchromesh is fitted to third and top gears.

The riveted chassis has rigid front and rear axles suspended by half-elliptic springs with hydraulic dampers. Braking is on all four wheels assisted by a mechanical servo, famously under licence of Hispano-Suiza. Separate rear brakes are fitted for the handbrake. The traditional Rolls-Royce radiator with triangular top was used with vertical louvres, the opening angle of which is controlled thermostatically to control engine cooling.

Park Ward was a British coachbuilder founded in 1919 which operated from Willesden in North London. In the 1930s, backed by Rolls-Royce Limited, it made technical advances which enabled the building of all-steel bodies to Rolls-Royce’s high standards. Bought by Rolls-Royce in 1939, it merged with H. J. Mulliner & Co. in 1961 to form Mulliner Park Ward.

Park Ward was founded in 1919 by William MacDonald Park and Charles Ward; they had worked together at F.W. Berwick Limited, the makers of Sizaire-Berwick cars. They built their first Rolls-Royce body in 1920. After producing bodies for a variety of cars in the early 1920s, Park Ward became particularly associated with W O Bentley’s new business, manufacturing their chassis nearby at Cricklewood.

Read more: Technologies, transport and equipment ...