Decad’s heroes
BMW’S late engine guru Paul Rosche turned an 80bhp Neue Klasse 1500 motor into the 1400bhp monster that powered Gordon Murrary’s brilliant Brabham BT52
I’ve been thinking a great deal recently about engine designers over the ages, from the three dubbed ‘the Charlatans’, who devised the first dual-overhead-cam units for Peugeot’s pre-ww1 Grand Prix cars, through to Keith Duckworth and his Cosworth solutions for F2 and F1 in the late ’60s. There is one name that often pops up in my studies, however, and that’s the late, remarkable Paul Rosche. Born in Munich in 1934, he graduated from his polytechnic and was immediately hired by a struggling BMW in ’57.
When Rosche came along, his ability to calculate profiles was much in need and would earn him the nickname ‘Nocken-paul’ (camshaft Paul). He was soon promoted by Alex von Falkenhausen to the performance engines division, where his cam work instantly improved the 507. Rosche had an innate understanding of how important the opening and closing of valves was to the power stroke. His breathing on that V8 turned it into a torquey, easy-to-use motor.
Rosche was heavily involved with the fourcylinder M10 unit for the Neue Klasse 1500. That morphed into the 1800TI and the 2002ti, which, when powered by the turbocharged M31, won the ’69 European Touring Car Championship.
Next was the F2 programme that BMW was running with March Engineering. With the Cosworth FVA in the ascendency, Rosche was able to produce the only engine that ever beat it. By 1973, he was head of the advanced development /racing department. The straight-sixes used by the Etcc-winning CSLS and the legendary ‘Batmobiles’ were expertly breathed upon by Rosche. Toine Hezemans won the title in 1973, followed by CSL victories every year from 1975’79. Try finding one of those cars today!
Rosche has perhaps become most famous for the M12 turbo engine that was used to great effect by the Brabham BT52 F1 cars designed by his great friend Gordon Murray. Utilising the cast-iron block from a 1500, Rosche worked up the power curve, increasing the boost – having developed fuels formulated to prevent detonation – until in 1982 the motor won its first race, the Canadian GP, with Nelson Piquet in a BT50.
By the time Piquet clinched the F1 title in ’83,
the M12 in the BT52 made so much power in qualifying trim that the dyno couldn’t measure it because it only went up to 1280bhp! I happened to be in the Monaco tunnel that year when Piquet came barrelling through on full boost in practice. It scared me white… as close as I ever want to get to Armageddon.
Mindful of the M12 block’s reliability, Rosche used it as the basis of the S14 engine for the hastily conceived E30 M3. That 2.3-litre, 16-valve unit was designed in 14 days flat – hence S14 – and the M3 became one of the most successful racing cars ever, with 1500-plus wins to its credit. For me, though, Rosche’s finest work is contained in the S70/2 V12 motor that powered the world’s all-time greatest car. When the vehicle’s designer sat me in it for the first time, he said: “Are you holding tight? Are you ready for this?” Then he floored it; I was pressed into my seat as if a gorilla had thumped me on the back. Gordon Murray’s Mclaren F1: it makes a Patek Philippe watch look like a cuckoo clock. When the F1 won at Le Mans in 1995 – straight out of the box – it’s the only time that I can think of when a car had its aero package and its motor detuned to comply with the rules.
BMW used that engine in its 1999 Le Manswinning V12 LMR prototype, which was a collaboration with the Williams GP team. Rosche retired that year, and died in November 2016, leaving a legacy that BMW has thrived upon – going onwards and upwards, and doing precisely what he would have wished for.