- Chassis No.
The undoubted masterpiece from that great design genius Vittorio Jano was the eight cylinder, twin camshaft, supercharged Alfa Romeo engine which made its dramatic first appearance in April 1931, debuting in the Mille Miglia Race that year. This engine was to power both the sports and racing cars from Alfa Romeo and in motoring history took its place between the dominance of Bugatti in competition in the 1920’s and the arrival of the Silver Arrows from Mercedes towards the end of the fourth decade of the last century.
Vittorio Jano had been tempted to join Alfa Romeo from Fiat in 1923 by the opportunity to head his own department, sweetened by a substantial salary increase. The brilliant Jano joined the racing department in Milan in the Autumn of that year. His first major project was the six cylinder P2 racing car, winner of the 1924 European Grand Prix at Lyon and AIACR World Championship winning Grand Prix car in 1925, no mean achievement for the “new boy” from Fiat. Jano had been briefed in the Autumn of 1924 to develop a medium capacity light car with brilliant performance and by the time of the Milan Salon in 1925 the new 6C 1500, then designated the NR, was displayed in chassis form. This was soon followed by a more powerful twin camshaft model, the 1500 Sport, and this in turn by the landmark 6C 1750, a milestone car in Alfa Romeo history. Here was a truly great car that was to dominate its class in competition from 1929 to 1935 and yet was also a most desirable road car for the more touring minded sporting motorist.
It was however the introduction of the supercharged straight eight 2.3 litre engine in 1931 that set Jano at the peak of his profession, his sheer genius producing an engine that was so versatile that it was adopted for the company’s sporting touring cars as well as their out-and-out Grand Prix racers. It shared the cylinder dimensions of the hugely successful 1750 and in standard form developed a massive 142bhp at 5,000rpm. The engine was constructed in mirrored blocks of four with the camshaft drive gears amidships. The crankshaft was carried in ten plain white metalled bearings and the supercharger, water and oil pumps were driven from helical gears from each crankshaft. The new engine featured detachable, alloy cylinder heads and the engine throughout was designed for lightness, even the camshafts being hollow to reduce weight. Jano had first used dry sump lubrication in the P2 models in the 1920’s and reverted to this principle for the eight cylinder cars. The favoured supercharger was a Roots type and on the standard production engine produced 9 ¼ lb boost. The new car was available in two standard chassis lengths, which wheelbases of 9ft and 10ft 2 ins and the longer wheelbase cars were generally selected for touring purposes and the more luxuriously appointed coachwork of the drophead coupés and four seater tourers.
Favoured coachbuilders for the eight cylinder cars were Touring of Milan, Zagato and Castagna. Castagna in particular were noted for a particularly high quality of build with stylish interior wooden furnishings being notable features. This car would almost certainly have been styled at the drawing board of Emilio Castagna himself, who headed the design team until 1933. This particular Castagna drophead coupé typifies the expensive Gran Turismo car of the 1930’s with long flowing wings, raked windscreen, small but practical luggage trunk and a rear mounted spare wheel.