BRM P578

Author

admin

X-ray spec

Keith Howard probes the secrets of the car which ended BRM’s drought with Tony Rudd, the man who turned a lost team into World Champions

When Sir Alfred Owen, whose eponymous Owen Organisation had bought BRM in 1952, summoned Tony Rudd into his presence in autumn 1961, he had good news and bad. The good news was that he proposed to put Rudd in overall charge of the team, thereby sidelining BRM co-founders Peter Berthon and Raymond Mays.

The bad news was that Owen had done what nobody with an expensive pastime should ever do: count the cost. The figures showed that BRM had consumed over £1m to date, for which it had delivered — in scant compensation for the public ridicule it had attracted — a solitary world championship victory, at Zandvoort in 1959.

Not prepared to throw good money after bad, Owen issued Rudd an ultimatum: either the 1962 season was to be more successful or he would pull the plug. When, with an engineer’s desire for precision, Rudd asked what would constitute sufficient success, the two men agreed that two world championship wins — twice what the team had achieved over the years to date — would be the benchmark.

In the event Rudd and his team did rather better: four wins, the constructors’ title and the world championship for Graham Hill.

The car which prevented the curtain falling at Boume was the Type 57 — officially designated the Type 578 when fitted with BRM’s V8 engine rather than the previous Climax four — although to a generation of racegoers it would become known as the Stackpipe’ BRM because of the early car’s upswept exhausts. It began life as a product of BRM’s bizarre fiefdoms, with design of the engine jealously guarded by Peter Berthon, and that of the chassis and suspension falling to Rudd.

Both ingredients would make important contributions to victory in 1962, but the development path, particularly for the engine, was long and rock-strewn. Only after August 1962, when Shell had helped cure its high-speed combustion problems, did the V8 finally behave as intended. “We took the revised engines straight to Monza,” recalls Rudd, “and Graham and Richie Ginther just drove away from everyone.”

Yet this was the engine which infamously had a list of 26 things wrong with it when first assembled, including major items like the camshafts not fitting, the mandated starter motor being omitted and the compression ratio being 8.2:1 instead of 12:1. The engine which, it would eventually emerge, had Imperial (2in diameter) big-ends on the V16-derived conrods, married to metric (50mm) journals on the crankshaft! Plus big-end bolts incapable of sustaining the stresses incurred running to its envisaged 12,000rpm maximum, and incorrect crankshaft balance weights.

I put it to Tony Rudd that, in Bourne’s engine department at least, the design process at that time appears to have been decidedly hit or miss: “Well, a certain amount of missing went on. There were a lot of stupid mistakes.” None of which, due largely to an untiring if fraught development programme, prevented Sir Alfred being mollified and BRM surviving.

X-ray spec: BRM P578

A special short-nose version of the car was made for Monaco but the modification was not a success. Rudd: “The idea was that you didn’t get the nose crumpled when you ran into the car in front! But we found that, although we’d cut the nose off, the cars actually ran hotter. The shape of the inside of the standard nose slowed the air down and dispersed it all over the radiator core. With the short nose we only used the middle of the rad, so we overheated.”

Though Rudd is self-deprecating about his suspension design ability, the Type 57’s all-round double-wishbone system made it one of the fastest-cornering cars of 1962: “I was considered to be a bit of an amateur in this department and I used to get lots of fire from the Owen Organisation about it. I had this profound theory about lots and lots of wheel movement. The snag is, if you have lots of wheel movement you get lots of camber change. What this picture doesn’t show is that the bottom rear wishbones have a common inboard pivot — there is one large bolt attaching them to the car — so that they are as long as possible, to minimise camber change at the driven wheels.”

BRM placed a premium on chassis torsional stiffness and, unlike other teams who paid lip-service to it, actually took the trouble to measure it rather than plucking optimistic guesstimates from the air. Without access to his records (which are with Doug Nye for his BRM magnum opus) Rudd recalls that his spaceframe for the Type 57 achieved substantially over 3000lb ft per degree: “We had some lengths of extruded Duralumin that were actually main spars from the defunct Bristol Brabazon airliner, which we initially used for loading ramps. Each car had an Austin Loadstar transporter and the steel ramps we had used to buckle because the old V16 weighed well over a ton. The Brabazon spars did not buckle! For torsional testing we’d put one of them across the shop floor and bolt the car to it through its front suspension mountings, then fasten the rear of the car down at the pivot point and attach a six-foot lever to the rear suspension mountings, with a block-and-tackle and a spring balance at the lever’s far end. With 300lb on the balance we put 1800lb ft of torque into the chassis.”

One of BRM’s advantages for much of 1962 was that it had exclusive use of the Lucas shuttle-valve fuel injection system. This gave significantly more top-end power than the quad twin-choke Webers on customer engines, but according to Autocar at the time, the carburettors gave more power below 9750rpm. Rudd demurs: “I suspect that was Harry Mundy guesswork because I made bloody sure no power figures got out. We were in dreadful trouble with our customers because the carburettor engine was hard-pressed to give much over 180hp and they were complaining that the works cars, with over 190bhp, were so much quicker. But Graham used to say the carbs had better throttle pick-up.”

The first F1 engine to use slide throttles, the BRM V8 actually gained this feature by default when the original throttle butterflies proved sticky. Rudd: “It was the Lucas injection man, Eric Downing, who suggested we try slide throttles because he knew from Jaguar’s Le Mans programme that they worked. It was also his idea to try upstream injection — against the airflow —which made the engine much less sensitive to mixture. Our slide throttle was too good initially—when you shut the throttle the engine would suck on the slides and you couldn’t move them. We came up with a small bleed hole to cure this, enough to break the suction without upsetting the mixture. On the dyno the slides gave us 5 to 7bhp more.”

The first V8 refused to run over 9750rpm without misfiring. This was traced to the transistorised ignition system when Rudd tried V16 magnetos instead and the engine sailed happily up to the 10,500rpm maximum of Bourne’s dyno. The Lucas designers scratched their heads and eventually produced a revised design that could provide the 700-plus sparks per second needed at 11,000rpm

The ‘stackpipe’ exhausts were replaced by low primary pipes and a flattened expansion chamber, as shown here: “One time the megaphones fell off the stacks; Graham tried revving it higher and found he recouped power. That was a bit of inspiration.”

This car is fitted with the BRM five-speed gearbox, but has the rear ‘horse collar’ that could also accommodate the six-speed Colotti, which weighed less and, according to Graham Hill, was a dream to drive. But it had to be sidelined following repeated seizures. “It wasn’t Colotti’s fault,” says Rudd. “Nobody had told them that we were going to rev the engine to 11,000rpm. The oil pump was fitted on the inlet shaft and it cavitated, aerating the oil. Actually, the Colotti was a clever design that solved a lot of gearbox problems of the time.”