Rolls-Royce. 25-30. 1938. 6/4255cc.

The Rolls-Royce 25/30 built between 1936 and 1938 in an updated version of the 20/25 with larger engine to provide more power; as often, bodies on sized is placed on the early models causing complaints about its performance.²

Engineering

The engine 6-cylinder in-line, valve-superior is similar to that used in the 20/25 but increased in capacity to 4257 cc by increasing the cylinder diameter of 3.25 inches (82,6 mm) to 3.5 inches (88.9 mm), with one race remaining 4.5 inches (114.3 mm). The compression ratio is 6:1. A single carburetor Stromberg of downward current of air replaced the engine Rolls-Royce, and magneto ignition was no longer fitted, but that it provided a coil on standby.¹ Use the gearbox a four-speed in unit with the engine, and a manual change of the right hand traditional. It is equipped with synchronizers for gear third and higher.

The chassis riveting has the rigid front and rear axles suspended by suspensions of leaf spring semi-elliptical with hydraulic shock absorbers. The brakes are assisted on all four wheels by a servo-mechanical, famously under license by Hispano-Suiza. It is equipped with brakes, split rear for the hand brake. The traditional radiator cap triangular Rolls-Royce was used with vertical slats, whose angle is controlled by using a thermostat to control the cooling of the engine.