BRM Tyred and exhausted
The Brltlsh team sought Dunlop’s help after lts three star drlvers all suffered worrylng tyre fallures at the 1953 Albl GP
Enthusiast Hein de Groot always introduces himself as ‘The Dutch BRM Fanatic’. I was pretty familiar with much of Hein’s stuff, but he can always produce surprises, and one brandished at the Goodwood Revival was a copy of a Dunlop report detailing ‘Tyre Test on the BRM at Folkingham Aerodrome, conducted on July 24, 1953’.
They were not so much testing the car’s Dunlop tyres as investigating the degree to which hot exhaust gases from the V16’s side exhaust pipes might affect the car’s massive rear covers. This followed their recent nearcatastrophe in the non-championship F1 Albi Grand Prix on the very fast Les Planques country-road circuit in southern France.
That non-championship GP had been run on May 30, 1953, with all three BRM V16s present, to be driven by Fangio, Froilan Gonzalez and Ken Wharton. The entry combined Formula 1 and 2 cars, and a preliminary 10-lap heat was run for the nine F2 cars, then another for the 10 F1s. The combined entry then contested an 18-lap final.
It was hot, and the road surface was abrasive. After seven practice laps, Gonzalez had a 17-inch rear tyre burst. Next day, 18-inch rear wheels and tyres were tried, but 17-inch were preferred for the race. In the F1 heat Gonzalez’s left-rear Dunlop shed its entire tread and much of the sidewall rubber. Justifiably concerned, BRM fitted 18-inch wheels and tyres for the longer final, inflated to 701bs psi instead of 45. By lap seven the three dark green, supercharged V16s were again removing the earwax from the Albigeois in fabulous formation — 1-2-3. But then both Wharton and Fangio had left-rear Dunlops strip. Fangio really pressed on despite the stripped tyre, but recalled: “Now I don’t know why I did it, but something about braking into the previous corner must have felt strange, because I pressed the brake pedal in the middle of the straight and it flopped straight to the floor —I had no brakes at all. If I had not tested the brakes I would next have needed them entering the final tight right-hander before the pits, and the trees on the outside there… whooo!”
His car’s left-rear brake caliper was found to be packed with tyre debris, and the hub was cracked. Gonzalez then led from Rosier and Wharton until lap 12 — when his right-rear tyre stripped — and Ken was missing…
He had crashed violently approaching St Juery village, running wide in a 140mph curve and somersaulting off the roadside bank into a wall. Amazingly, he escaped with shock and bruising, while Gonzalez finished second behind Rosier’s Ferrari.
Wharton’s crash had not been caused by another tyre failure. All four were found intact at — or near — the scene. The subsequent temperature tests at Silverstone and Folkingham investigated ‘the temperature conditions in the air stream around the rear tyres, as part of an investigation into the causes of the tread stripping at Albi’. There, the side-exhaust outlets had been just three inches ahead of the rear tyres. For Silverstone testing eight-inchshorter pipes were tried. Hein’s report states dryly: ‘This was the first running made on the cars since Albi, and although the BRM were (sic) cooperative, much testing time was lost due to mechanical troubles on the car’.
They found airstream temperature over the rear tyres was raised 10-60deg C above ambient. Using tyres with 4-6mm tread thickness running at 421bs psi, and averaging 90-95mph for nine minutes, tyre tread temperature was 65deg C. Dunlop recommended `…the exhaust outlet should be moved to the rear of the tyres, without further delay, certainly before the car is run at Monza’ — as then planned. Air temperature between exhaust outlet and tyre with the Silverstone exhaust was found to be 80deg C — 61 above ambient. Short stub pipes were then tried, eliminating the extreme local temperature, but still raising the airstream temp 10deg C. An extension pipe was then fitted in the Silverstone exhaust’s angled outlet, and in tests at Folkingham this reduced temperatures around the rear tyre to only 10-25deg C above ambient.
Today multiple electronic sensors infest every F1 car. The 2009-2010 McLarenMercedes MP4-24s and 25s have carried temperature sensors monitoring engine oil, gearbox oil, hydraulic fluid, water, KERS oil, exhaust gas, the rear suspension links inboard ends (eight of them, vulnerable to engine and gearbox heat), brake calipers, brake discs, tyre temperatures both internal and surface, a dozen or more electrical ‘boxes’, bodywork in the exhaust stream, gearbox casing, intake air and fuel within the tank. In testing they sometimes add other specific sensors in areas of concern or interest. Modern sensors are tiny, but while infra-red sensors are used for the brake discs and tyre surface temperatures, sometimes — only in practice — thermal cameras capture a more complete picture (literally). So tyre temperatures are now monitored continuously in motion, to help with set-up and tyre durability, and also to help warming tyres to the correct level for starts and re-starts after a safetycar period. Which isn’t something that ever troubled the V16 BRMs…
Back in 1953 Dunlop obtained its data using steel bulb vapour-pressure thermometers, `…the steel bulbs fastened to fabricated rigs positioned in the tyre air stream, as close as safe to the tyre. The indicator dials were fixed in the cockpit so that the driver could read them during the run. The highest readings (at Folkingham) were noted on the 1.1-mile straight’.
A rather rueful note adds: ‘Maximumreading thermometers, fitted in metal tubes, were tried. These were soon damaged by stones…’
Some 500bhp, with a delivery curve resembling the Matterhorn, transmitted through seven-inch-wide iron-hard tyres to a crumbling track surface was never going to prove very much, beyond the dimensions of the drivers’ cojones — or their IQ. So when you hear current F1 stars being exhorted to “watch your tyre temperatures” just sit back, and think of the V16 BRMs at Albi in 1953.
A punch-start for ‘deaf’ Hill
Former Le Mans Jaguar exponent Peter Lumsden of ‘Lumsden/Sargent’ fame, vividly recalled from so many middle-of-the-night Raymond Baxter radio commentaries in more recent years created a wonderful hotel and restaurant named The Old Tollgate in Bramber, near Steyning, Sussex. Regular BRDC area lunches take place there and for their Christmas bash I took along Phil Hill’s son Derek erstwhile Formula 3000 driver and a really good guy (who endured my slithery-sliding our way down there in deep snow in the Land Rover).
Who should we bump into as we walked through the door but former Cooper mechanics Mike Barney and Terry Kitson, who had worked with Phil during his albeit unhappy period as a Cooper works driver in 1964. In fact both Mike and Terry got along well with Phil, and classical music buff Terry the team’s specialist welder vividly recalled the 1961 World Champion demonstrating a brand-new hi-fl set he’d just acquired, in his room at the Nurburgring Sporthotel during the German GP meeting. Terry recalled Phil insisting they appreciate and savour the full tonal range from those brandnew speakers as he cranked up the volume fit to burst: “It was great we were there for hours, Phil really loved his music…”
Mike and Terry also recalled an incident on the starting grid for the Belgian Grand Prix at Spa. Phil had qualified way back 15th in fact and then had trouble starting his car’s Climax V8 engine on the signal. The Cooper lads realised he was trying to start the thing in gear but in the general heat of the moment and the flurry of Formula 1 engines starting up all around him, he didn’t seem to notice. “Phil!” they were bawling. “Knock it out of gear!” Wearing his car plugs and crash helmet he simply didn’t hear them. But just huffing the starter buffon in the firmly chocked car wasn’t working. It seems that Hughie Frankland, the South African mechanic on Phil’s car, then wasted no more time. “He just took the biggest spanner from his tool kit,” Mike recalled, “and whacked Phil across the crash helmet. That got his full affention…”
As well it might. Not sure it would be received today in the helpful spirit intended…