I knew him from the time I joined the Bentley company as an apprentice in 1928 where "Wally" Hassan was a fitter in the chassis erecting shop. He had started there in 1920, first as a hand, then as a fitter's mate, then as a fitter in the engine shop before moving into the chassis shop and eventually to road testing. This was before the time when fitters were only concerned with engines or chassis, so Wally Hassan had complete experience of the three-litre Bentley cars which were being produced at the time.
From the first he was an exceptional man. He had no burning ambition but a determination to know and understand every item on the cars he was building. His father's business was a clothing shop in London, but Wally's interest was always in mechanical things. After a few years at Bentley's he took an evening course of automobile engineering at the Regent Street Polytechnic in London.
At Bentley's he worked closely with the company's professional racing driver, Frank Clement, who recommended that he be attached to the racing mechanics for the team cars at Brooklands and Le Mans; as he was soon established as the best Bentley mechanic he was allocated to the top driver, Woolf Barnato, who was also the company's financier and chairman.
Barnato and Hassan established a close friendship which lasted until Barnato died in the 1970s. When Barnato retired from racing he employed Hassan to prepare his racing cars to be driven by others. The most successful of these cars was known as "old No 1", the speed six with which Barnato had won at Le Mans in 1929 and 1930. That car ran its last race in 1931, when it won the 500-mile race at Brooklands driven by Jack Dunfee and Cyril Paul. After the race the car was broken up and the six-and-a-half- litre engine sold to another driver who put it into another Bentley chassis - in this way the history of famous racing cars gets muddled, and causes confusion.
In 1931 Hassan built up a new Hassan Bentley Special which Barnato entered for another 500-mile race in which Clive Dunfee (Jack Dunfee's youngest brother) was tragically killed.
Hassan built up two other special Bentley racing cars for Brooklands. The Pacey Hassan and the Jackson Bentley Special were the fastest outer circuit racing cars at the time, very nearly approaching the speed of John Cobb's Napier Railton which held the Brooklands lap record.
Wally's next move was to the ERA (English Racing Automobiles Ltd) at Bourne in Lincolnshire where he worked on the development of the ERA engine with Peter Berthon before returning to the south to Thompson and Taylor at Brooklands, where they designed the ERA chassis. A few years later he went north again, and joined Bill Lyons at the SS Jaguar Cars company at Coventry. There he worked with Bill Heynes developing a new overhead valve engine.
At the outbreak of the Second World War Hassan joined the Bristol company on aircraft production. Lord Brabazon of Tara, the Minister of Aircraft Production, reported that Hassan should be given every opportunity to use his special skills and ability on engine development. After the war Hassan returned to Jaguar at Coventry helping Bill Haynes develop the great XK engine.
When I was racing a Jaguar-engined special and Hassan took me to an event in his XJ saloon, I noticed the great acceleration of that car. Hassan said: "It is not what you think," and then showed me the engine, which was a new Jaguar V8 unit. Hassan said: "I really like working for Jaguar because their organisation is so good that they can make any engine just as an experiment," and in fact no V8 Jaguar engine was ever produced. He then went on to join an old friend Harry Mundy at Coventry-Climax where they were engine specialists.
In the 1950s Hassan and Mundy worked with Claude Bailey on new Formula One racing engines for Colin Chapman at Lotus. These engines were a tremendous success, several times bringing the world championship to Jim Clarke and Lotus.
All this time Hassan kept in close contact with Bill Heynes at Jaguar, and when Jaguar took over Coventry-Climax in 1963 they had the strongest team in the motor industry: Mundy, Hassan, Bailey and Heynes who together developed new V12 engines, not only for the luxury Jaguar road cars but also for sports car racing at Le Mans when they twice won the 24-hour race where Hassan had first tasted success with Bentley's.
Wally Hassan continued to develop the V12 Jaguar engine until his retirement in 1972, but even after that he was a leading consultant on engine design. He was always a family man, with a devoted wife and three sons and a daughter, and after the death of his wife he lived with his son Bill at Kenilworth before moving into the Motor Industries Benevolent home.
It is difficult to assess Wally Hassan extraordinary engineering ability which was certainly helped by his amazing memory. Frank Clement once said that Hassan was the only mechanic who knew every inch and nut and bolt on the Bentley cars, and 60 years later he retained the same detailed memory of all the engines with which he had been concerned. Today's motoring enthusiasts remember him because of the V12 Jaguar engine, but his fame was just as great as a result of the Coventry-Climax Formula One racing engines and the Bentleys at Le Mans.
Walter Thomas Frederick Hassan, automobile engineer: born London 25 April 1905; OBE 1971; married (wife deceased; three sons, one daughter and one son deceased); died Easenhall, Warwickshire 12 July 1996.