KEITH DUCKWORTH, the ebullient race engine designer, was a founder of the Cosworth concern. Along with his colleague and friend, Mike Costin, he had set up Cosworth Engineering in 1958, and guided it to worldwide fame in the field of high-performance automotive engineering. Among many famous power units, he designed the legendary Ford-Cosworth DFV V8 Formula One engine, which, with 155 victories, is the most successful engine to be used in Grand Prix racing.

David Keith Duckworth was born in Blackburn, Lancashire, in 1933, into a family with roots in the cotton weaving industry. Having spent eight years at Giggleswick School, he then studied engineering at Imperial College, London, where, as he always cheerfully admitted: “I just scraped through with a pass. No way was I going to get honours.”

For his first job, he became a development engineer at Lotus, where he met Costin, and forged a lifelong friendship with the man who was to become his business partner.

After only one year, he left Lotus. Along with Costin, they then set up Cosworth Engineering, originally with an authorised capital of £100. Working alone at first (Costin’s contract at Lotus could not be broken until 1962), and using borrowed premises in Kensington, he set out on a career defined by his famous aphorism that: “It must be possible to make an interesting living, messing about with racing cars and engines.”

After moving to the Railway Tavern, Friern Barnet, in 1959, he developed Cosworth’s first Ford-based Formula Junior engine, which was supreme and won hundreds of races. After that, Cosworth’s expansion was swift, necessitating a move to Edmonton in 1962, and finally to a new factory on a green-field site in Northampton in 1964, where it remains to this day.

Once Costin had become the chief development engineer, Duckworth concentrated on the design of a series of fine race car engines, including the SCA F2 power unit. Then, in 1965, came the famous link up with Ford, which gave birth to two outstanding power units — the FVA F2 engine, and the 3-litre DFV V8 F1 engine. Having spent months on these projects, Duckworth perfected the use of the narrow angle/four-valves-per-cylinder/twin-overhead-camshaft cylinder head layout, which the rest of the industry made haste to copy.

Duckworth’s dedication to these projects almost caused him a health breakdown, for he suffered serious eye strain and later commented that: “I deliberately went on a diet, which seemed to consist largely of steak and cabbage, and as a result I lost 40 lb.”

Although Duckworth always protested that Cosworth expanded without encouragement from him, this came because of the demand for the products that poured out of the company in the 1960s and 1970s. Those not actually designed by him were always influenced by his thinking, his discussion of all features and by his constant attention to detail.

Once described as “multitalented, super-confident, deep-thinking, forthright, stubborn, often combative, dismissive of fools, gregarious in company, but dangerous in argument . . . a one-off in every respect”, he was an unforgettable character.

It was often said that it was never wise to start a brief discussion or phone conversation with Duckworth, as these were simply not possible. Every problem, and every opportunity, would be argued in great detail; it was not until he was totally satisfied that any meeting would be brought to a close.

Although he was the founder, main shareholder and chief engineer of Cosworth, he never truly enjoyed the management of the business itself. From 1980, therefore, he sold his company to United Engineering Industries, though remaining as chairman. Later Cosworth became a leading supplier of high-performance road car engines to Ford, Mercedes-Benz and General Motors. He inspired the birth of the turbocharged 120-deg V6 1½-litre Ford F1 engine: this eventually produced 1,000bhp — which was, and still is, the most powerful engine produced by Cosworth.

In the 1980s the Cosworth business grew so large that he could no longer control its engineering as closely as he would have liked, so in August 1988 (when he was still only 55 years old), he stepped down from the chair in favour of Mike Costin. After Carlton Communications took over UEI in 1989 and planned to sell off Cosworth to the Vickers Group, he tired of business, handed over his remaining engineering responsibilities, and retired to his hill-top house, close to Northampton.

Having been chairman and chief engineer for so many years, he stayed closely in touch with the company for years after that, regularly attending reunions and the launch of new products. In later years he could always be relied upon to upset an otherwise tranquil discussion with one incisive comment.

During the 1960s, when he had little time to relax, he made the most of it, by buying a small helicopter, and learnt to fly it himself. Other helicopters followed in later years: it was not until doctors warned him off after a heart scare that he reluctantly hired a pilot to chauffeur him around the country.

His first marriage, to Ursula Cassal, ended in divorce. There were a son and daughter. His second marriage, to Gill Reeve, was in 1987. She and his children, survive him.

Keith Duckworth, founder, chairman and chief engineer of Cosworth Engineering, was born on August 10, 1933. He died on 19 December 2005, aged 72.