BRM P261

Chassis BRM P261, showing the distinctive, barrel-shaped engine cowling Colin Chapman's monocoque Lotus 25 of had put the writing on the wall for older spaceframe chassis designs, and most other Formula One constructors hurriedly started work on their own monocoque cars. The BRM P261 was British Racing Motors's first fully monocoque chassis. Its prototype, the one-off P61 introduced in , pioneered many of BRM's monocoque elements, but used a tubular subframe for its rear engine mounting. As its name suggests, with the P261 (or P61 Mark II) designer Tony Rudd simply built upon the P61's structure, rather than introducing a completely new car. To emphasize this continuity, the P261 chassis numeration continues the P61 sequence, with the first P261 chassis being numbered 2612. BRM had some previous experience of stressed skin construction with the BRM P25, so Rudd was in a good position to be able to exploit the new technology to the full. This previous experience meant that Rudd's use of the monocoque was somewhat different from the pioneering Lotus's frame. Where the 25 had been a channel-section frame with an open top, within which the driver sat, the P261 chassis was a slim tubular-section, into which a hole was cut to allow the driver to gain access. It was further uprated to 2.0 litres as the season progressed. For the P261's 1967 trip to the Antipodes the engine capacity was stretched yet further, providing the ultimate version, which also saw service in a few Formula One races later in the year. In an attempt to keep the P261 competitive into 1968, the fifth chassis was fitted with the new, 3-litre V12 BRM engine, but without success. Ancillaries Fully independent double wishbone suspension was employed at all four corners. Another significant change made from the P61 design was to move the suspension shock absorber components outboard at the rear. This switch was initially made to accommodate the extra cam-cover space needed to employ the 32-valve motor, but though that unit was shelved the suspension geometry was retained. At the front, the coil spring and damper units were retained within the monocoque skin, resulting in a clean, aerodynamic profile around the car's nose-cone. Braking was by outboard-mounted, Dunlop disc brakes all round. A total of six BRM P261 cars were constructed, with both the first and last chassis built being written off during their careers and rebuilt by the factory. All six survive. ==Competition history==

1964 The BRM P261 made its race debut at the non-Championship Daily Mirror Trophy race, at Snetterton on 14 March 1964. Only one car was ready at the time, and it was entered for long-serving works driver Graham Hill. The car immediately showed its promise, as Hill took second place in qualifying, beaten only by newly crowned World Champion Jim Clark's Lotus 25. Unfortunately for Hill, in the race itself he retired following an accident on only the seventh lap. The early season shakedown races continued well for the BRM team; Hill set fastest lap at Goodwood on 30 March, and was only prevented from winning when the car's rotor arm dropped off two laps from the end. Hill added a further two second-place finishes, at the Aintree 200 and BRDC International Trophy races, before the first race of the World Championship season. (in the pale duffel coat) oversees BRM mechanics pushing driver Graham Hill out on to the track, during testing of a BRM P261 Despite the rather interim nature of its engine and chassis configuration, on its World Championship debut at the 1964 Monaco Grand Prix the BRM P261 had the best of starts. Although Hill and team-mate Richie Ginther only managed to qualify in third and eighth places, respectively, in the race Hill set fastest lap, and the two P261s finished first and second. It was the second of Hill's five victories on the Côte d'Azure. Hill continued to perform well throughout the first half of the season, and took a string of three back-to-back second places in France, Britain and Germany. Ironically, it was with the introduction of the proper, high-exhaust version of the engine in Italy that the car's reliability began to falter. At Monza Hill qualified on the front row of the grid, but as he sat waiting for the flag to drop his clutch seized open, and his car sat stationary as the rest of the field streamed past him. Hill bounced back to win in the United States, but finished out of the points at the season finale in Mexico following a collision with Bandini. With reasonable results from Ginther, BRM finished the season second in the Constructors' Championship, with Hill also second in the Drivers' Championship. 1965 in his BRM P261, leading in the early laps of the 1965 Dutch Grand Prix. He had started in pole position, but finished the race in fourth. BRM's new driver signing for the 1965 Formula One season was promising young Scot Jackie Stewart. In his very first race meeting for the team, the 1965 Race of Champions at Brands Hatch, Stewart used his P261 to immediately make his mark, taking second place in the overall aggregate positions after two heats. Stewart took his first outright race win in that year's International Trophy race. Fortunately for BRM, the car's late season lack of reliability had been cured by the time that the 1965 World Championship season began, and of the BRM P261's twenty Grand Prix starts only four did not result in a points-scoring finish. Hill again won in Monaco and the USA, while Stewart eventually took a closely contested Italian Grand Prix, his first ever World Championship race win in only his first Formula One season, wiping out memories of the previous year's humiliation at Monza. Again BRM took second spot in the constructors' standings at the season's end, with Hill and Stewart taking second and third, respectively, in the Drivers' Championship. 1966 Following the end of the 1965 World Championship season, BRM fitted two of their chassis with the enlarged, 1.9-litre version of the V8 engine, and shipped them to Australia and New Zealand to compete in the Tasman Series. Hill and Stewart accompanied them, along with substitute driver Richard Attwood, and immediately set about dominating the championship, despite the P261 giving away over half a litre to the older Climax-engined cars. World Championship results (key) (results in bold indicate pole position) This total includes points scored by BRM P83 cars Non-championship results (key) (results in bold indicate pole position; results in italics indicate fastest lap) Tasman Series results (key) (Races in bold indicate pole position; results in italics indicate fastest lap) ==References==