In 1945, British Racing Motors (BRM) was formed. It raced from 1950 to 1977, winning 17 of the 197 Grand Prix's they contested. One of their earliest projects was an ambitious one, a 1.5-liter supercharged V16. The project never lived up to expectations, and by the time all of its short-comings had been resolved, the V16 was no longer eligible for Grand Prix events.
In late 1955, BRM introduced the P25. It was powered by a twin-cam 2.5-liter four-cylinder engine designed by Stuart Tressillian It was given two twin-choke weber carburetors and installed in a steel spaceframe chassis. Suspension with comprised of wishbones and coil springs in the front and a DeDion setup with a transverse leaf spring in the rear. Also in the back was a single disc brake which slowed both back wheels. In the front were Lockheed discs in the conventional fashion. The car was quick, but it had handling and reliability issues. Dirt and oil would collect on the rear disc, hindering its stopping ability. The engine with its large valves proved to be another problem area for the car.
The 1956 and 1957 were also disappointing years for BRM. For 1958, they enhanced, modernized, and improved the P25 even further. The front suspension was changed to coil springs which seemed to help with the vehicles handling. The engine still had issues though; having switched from alcohol-based fuels to pump gasoline, the engine often overheated.
For 1959, BRM had resolved the overheating issues and the Lockheed disc brakes were replaced by Dunlop brakes. In the back was still the single rear disc. Finally, the P25 had been transformed into a true contender. The first Grand Prix victory for BRM was at Zandvoort with Jo Bonnier at the wheel.
Just as the P25 was starting to win, Cooper changed the playing-field by introducing their mid-engine racer, basically making the front-engined cars obsolete.
BRM quickly made a mid-engine version of the P25. Other than the layout, the mechanical components of the P25 and P48 were nearly identical. In late 1959, the P48s made their debut.
For 1960, several changes were made, such as replacing the single disc brake with two discs. This would also be the final year for the four-cylinder BRM's as rule changes for 1961 limited displacement size to 1.5 liters.
For 1962, the BRM team introduced the Tony Rudd designed V8-engined BRM P57.
In total, there were seven examples of the BRM P48 produced. By Daniel Vaughan | Jul 2012