The BRM P261 was an evolution of the previous year's experiment with monocoque construction, pioneered by Lotus. 1963's one-off P61 suffered from excessive chassis flex and only ran in two races. In contrast, the BRM P261 was introduced in 1964, and was still being entered in Formula One Championship events right up until 1968.
The chassis design was very much a continuing development of the P61, and since designer Tony Rudd had some previous experience of stressed skin construction with the BRM P25, he was in a good position to be able to exploit the new technology to the full.
The P261 was designed to use the P56 engine, introduced in 1962. However the exhaust pipes were intended to have a different configuration, exiting through the channel in the middle of the V of the engine, on top of the car. Unfortunately the new configuration wasn't ready at the start of the season, and some modifications had to be made to the body to allow the use of the older version of the engine.
A Good Start
The 1964 Formula One season proved to be fiercely competive, with the Drivers' Championship being decided by a single point. Last year's Champions Lotus continued with Clark and the 25, Ferrari returned to a competitive level with Surtees driving the new 158, and of course BRM brought their new car the P261 to the championship, with Hill at the wheel.
BRM started perfectly with a 1-2 finish in Monaco, with Graham Hill leading home Richie Ginther. But then Lotus fought back with Jim Clark taking three wins out of the next four, before reliability problems started to plague the team. John Surtees joined the fray with two wins in the second half of the season, and Hill took his second victory in the penultimate race.
Going into the final race, Hill lead the championship, but Surtees and Clark were still in with a chance.
Mexican Grand Prix
Clark led for most of the race, and he was in a position to take the championship right up until the final stages, when an oil line failed and his engine seized just as he was starting his last lap.
Hill had been backended by Bandini and was down on power, but with Clark's retirement he could still win the championship.
But realising that Surtees could now win the title if he finished second, the Ferrari team manager frantically signalled his team mate Bandini to slow down and handover the place. Bandini complied, and John Surtees won the Drivers' Championship by just one point from Hill.
Ferrari also won the Constructors' Championship, with BRM again second.
As it happens, Hill had actually scored more points than Surtees over the season, but because only the best six results counted towards the Championship, Hill lost out.
1964 BRM P261
The 1965 season was not nearly so exciting, though fans of Jim Clark would no doubt have enjoyed his complete dominance.
Clark took six wins in the first seven races of the season, missing out on Monaco as he was away winning the Indianapolis 500.
In a season of ten races, and a points system that only allowed the best six results to count towards the championship, the winner was certain long before the end.
BRM didn't do too badly, with Graham Hill taking second place in the championship for the third year in succession, and new signing Jackie Stewart taking third place on his debut.
But Jim Clark and Lotus were dominant, and his reliability problems at the end of the season were of no real consequence.