SLIDESHOW Road car engines that powered famous competition cars he origins of many great motorsport engines can be traced back to a road car, and often an entirely unremarkable one. Some were developed with a specific series in mind, others went on to power many and varied competition cars and several were transformed beyond recognition. Here are our picks of the best engines that went from road to race.
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Audi straight five Audi’s development of four-wheel drive from a military truck to rally stages is well documented, but the Quattro’s 2.1-litre five-cylinder engine had more prosaic beginnings, starting life in Audi saloons with 170bhp. For the rally coupé, it gained a further 30bhp, giving 0-60mph in 7.1sec and 137mph in 10-valve form. To qualify for the World Rally Championship, it had to be reduced in capacity from its normal 2144cc to 2133cc, but it gained four valves per cylinder and a KKK K27 turbo for 300bhp at 6700rpm. The later A1 and A2 versions produced 350bhp, while the Sport had 444bhp. Its final fling came with the 473bhp S1 E2 Quattro that arrived just ahead of the Group B class being banned after a series of fatal crashes.
ALISDAIR SUTTIE
BMW M10/M12
Ford Kent
Austin A-series
When BMW launched the Neue Klasse saloon in 1962, survival rather than sport was on its mind. But it succeeded, and BMW then enjoyed many wins with its engine in the 1800ti, 2002 and first 3 Series, as well as in F2 with more than 300bhp. However, 1983 was the real turning point. Brabham needed a new F1 engine, so BMW created a 1.5-litre turbo derivative of the M10 .Compact and reliable, the M12 eventually hit 1400bhp. F1 banning turbos in 1989 ended its racing career.
The Kent is arguably the most successful engine ever in motorsport, having powered thousands of victories around the world, yet it all started with the lowly 1959 Ford Anglia. It showed a willingness for being tuned and was quickly adopted for use in cars like the Lotus 7. Lotus also used it as a base for the DOHC unit that powered its Elan, Cortina and Escort Twin Cam. Then the Kent became the standard unit in the Formula Ford racers that are still hugely popular, as well as in Formula 2 and 3.
The A-series arrived in 1951 and quickly achieved competition success in the likes of the A35 and Sprite. However, it was the agile Mini that proved the catalyst for its huge successes. It started with the 1961 launch of the Cooper, with the engine’s 848cc and 34bhp raised to 998cc and 55bhp. Then came the 70bhp Cooper S, which did well on track and stage. And finally the 1275S, which was capable of 115bhp – enough to win the Monte Carlo Rally three times between 1964 and 1967.
Porsche flat six
Rover V8
Volvo straight five
It didn’t take long after the 911 arrived for Porsche to start rallying the 1991cc model, which enjoyed plenty of success as capacity grew to 2195cc. Its focus switched to track with the 210bhp Carrera 2.7 RS, and then Porsche went Group 4 racing with 300bhp. This was followed by the 3.0 RSR racer and then the RSR Turbo in 1974. Out of this came the twin-turbo 3.3-litre Group 5 935, which made up to 845bhp – enough for 70 IMSA wins.
Rover was slow to realise the racing potential of the V8 it inherited from Buick. The Triumph TR7 was the first works car to adapt it for competition; it raced in the TransAm and IMSA series in the US, while here it went rallying. The 3.5-litre engine gained four downdraught carbs and dry-sump lubrication to make 260bhp (eventually 300bhp). Rover also used the V8 for the SD1 touring car, built with help from TWR, that scored many wins.
Perhaps uniquely, TWR reduced the capacity and removed the turbo of an engine yet gained power, cunningly turning Volvo’s 240bhp 2319cc five into a 325bhp 1999cc to meet the BTCC Super Touring rules. Now sitting much lower and farther back in the 850’s chassis, the engine revved to 8500rpm and drove via a six-speed sequential gearbox. The estate wasn’t the quickest 1994 BTCC racer, but it more than did the job of changing Volvo’s image.
82 AUTOCAR.CO.UK 13 APRIL 2022
