Keith Duckworth

David Keith Duckworth, engineer: born Blackburn, Lancashire 10 August 1933; married first Ursula Cassal (one son, one daughter; marriage dissolved), second 1987 Gill Reeve; died Northampton 19 December 2005.

British motorsport will forever owe a huge debt to the engineer Keith Duckworth. With Mike Costin, with whom he had co-founded Cosworth Engineering, Duckworth designed the Ford Cosworth DFV V8 engine, which first appeared in 1967 and went on to win 155 grands prix and 23 world championships for British teams such as Lotus, Tyrrell, McLaren, Williams and Brabham, and drivers such as Graham Hill, Jackie Stewart and James Hunt. Without the DFV, Britain would not have been able to maintain the domination it had enjoyed from 1962 to 1965 with Coventry Climax's engines under the 1.5-litre Formula One.

Duckworth was born in Blackburn, Lancashire in 1933, and educated at Giggleswick School in Yorkshire. He studied engineering at Imperial College, London from 1952, upon completion of his National Service with the RAF, and decided on a career in engineering after toying with the idea of being a commercial pilot.

In 1957, he joined the emergent Lotus founder Colin Chapman as a transmission specialist, but two geniuses in one camp was one too many and in 1958 Duckworth and Costin famously put their names together to form Cosworth. Initially they ran their no-frills operation out of Shaftesbury Mews in London - "We thought it must be possible to make an interesting living messing about with racing cars and engines," Duckworth said - before moving via Friern Barnet to bespoke premises in Northampton.

Initially, they developed Climax engines and Ford roadcar units, until in autumn 1965 they were commissioned by Walter Hayes, the former journalist who was by then head of motorsport at Ford, to design and build two racing engines. The first was a 1.6-litre, four-cylinder Formula Two engine, the FVA, the second a 3-litre Formula One V8. Both were hugely successful. The DFV won on its début in June 1967 in the Dutch Grand Prix, in the back of Jim Clark's Lotus, and went on to become the mainstay of grand prix racing in the Seventies.

"That engine was literally done by Keith, and he designed all the test rigs for it, too," Hayes recalled in 1997.

And he allowed me to spend Ford's £100,000 in instalments . . . I think we should recognise it as a kind of foundation point when we established this country - in an international fashion - as the place where you go to have motor-racing cars and engines made.

The Cosworth DFV (the letters stood for Double Four Valve) came at a time when British manufacturers desperately needed a new proprietary engine, following the withdrawal at the end of 1965 of Coventry Climax. In 1966, the first year of the new 3-litre Formula One, only one of the British-based teams was well placed, and that was Brabham, with Australian Oldsmobile- derived single-cam V8 Repco engines. As Ferrari, Honda, BRM and Cooper struggled with heavy and underpowered engines, Lotus had to make do with underpowered 2-litre versions of the Climax V8 or BRM's hideously complex and overweight H16.

The arrival of the Cosworth DFV changed everything. It was a triumph of design that in one imperious stroke redefined Formula One's parameters, and bequeathed a dramatic legacy, with 400 bhp and super-lightweight. All of a sudden, aspiring owners such as Ken Tyrrell could once again put a Formula One team together around the engine which was not just the best but which, crucially, was available commercially to anyone.

It paved the way for teams such as Williams to gain their first footholds on the mountain, and made winners of less well-known outfits such as Hesketh, March, Penske, Shadow and Wolf. Later, in DFX guise, the engine and its derivatives enjoyed fresh success in turbocharged form in American IndyCar racing, winning the famed Indianapolis 500 on several occasions.

Eventually, Duckworth and Costin sold Cosworth, which subsequently changed hands several times. In 1973, a heart attack forced Duckworth to relinquish his helicopter licence, but he oversaw Cosworth's racing activities in Formula One's turbo era in the Eighties until heart surgery obliged him to retire as chairman of the company in 1987.

David Tremayne