In November 1904, the Marquis de Dion addressed a gathering of the French motoring industry, held at the Automobile Club de France in Paris. He reflected on the contribution that France had made to the technical development of the motorised passenger vehicle, and the role of his own company in particular. As for the future, he was convinced that the future prosperity of the company lay in small vehicles and trucks. Given the evident success and prosperity that had been gained from producing small-engined vehicles, this approach was simply a matter of building on already strong foundations.
By the end of 1905, however, this strategy was already unravelling, and in 1906 a range of motor buses was launched that rapidly became a familiar sight on the streets of Paris, London and New York. Twin cylinder car production came to a halt in 1908 (only to be re-kindled in 1911), the first V-8 engine was displayed at the Turin Motor Show in 1909, and by 1911 the bulk of the company’s production was four cylinder vehicles with various engine configurations: small cars had engines of 10/12hp; mid-sized cars were equipped with 14/18hp power units, and the top of the range vehicles had 25/30hp options, entirely adequate for formal Landaulet coachwork. The growth of the commercial vehicle business, for trucks and buses, for which the larger engines were necessary, was becoming very significant, and so the overall approach offered rather better economies of scale. There were other considerations too: by 1909 the huge number of competitors had ensured that margins on single and twin engined cars had been tightly squeezed.
Robust though the strategy was around the manufacture of four cylinder engined vehicles, many manufacturers in Europe and North America were focused on achieving the optimum balance of power, smooth running and quietness from their engines, and in this respect four cylinder engines had their limitations. The development of a six-cylinder engine was an obvious next step. Georgano reported that by 1908/9 some 62 makes of six cylinder cars were on sale in Great Britain, and a small number of French manufacturers including Darracq, Delaunay-Belleville and Renault had produced six cylinder engines, but difficulties persisted. Six cylinder cars had the theoretical advantage over their smaller relations of increased torque and the attractive necessity for fewer gear changes, but the longer crankshaft, of lighter construction to save weight, inevitably led to torsional vibration, with broken crankshafts and engine failure as the final outcome.
Quite apart from work on six-cylinder engines, there had also been development of eight-cylinder power units. The earliest development work on eight-cylinder engines had taken place in France as early as 1903 with the straight-eight of CGV and the V-8 designed by Clement Ader; the former never went into full production and the latter was created with the 1903 Paris-Madrid Race in mind, and was never offered for sale. Rolls-Royce made three ‘Legalimit’ V-8 cars in 1905, and in the same year Darracq produced a 22.5-litre V-8 that took the Land Speed Record at the end of the same year. The French Antoinette company designed a V-8 engine in 1906 that was declared suitable for airplanes or motorcars.
De Dion Bouton had an interest in the V-8 engine, but it was not confined to motor car application. In 1908 work also started on the design and development of aircraft engines, and there were distinct synergistic benefits to be had in the technical development and production of both. The first indication that the company was seriously considering this particular opportunity was the patenting by De Dion Bouton in 1908 of the fork and blade arrangement of connecting rods, enabling the location of pairs of cylinders on the same vertical axis, which in turn required a shorter crankshaft and the potential for one camshaft. When combined with a twin throat carburettor, one throat for each range of cylinders, the end result was a power unit with effortless torque and smoothness, entirely suitable for the most substantial coachwork.
Next week, we will publish part 2 of this article. Michael Edwards is preparing a volume on De Dion Bouton motor cars from 1905 – 1914, and would welcome any information on the whereabouts of any examples of these elusive V-8 vehicles, as well as the larger engined, 25/30hp four-cylinder vehicles from the period. If you have any information on these cars, please send us an email and we will forward it to Michael: office@prewarcar.com Special thanks to the De Dion Bouton club of the UK for their contribution in this research. |
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The Launch and Decline of the V-8; part 1
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