The Type 10 Bugatti
By E. K. H. Karslake
The history of Bugatti has for long been so assiduously studied by erudite specialists that I have considered it a subject best avoided by amateurs like myself. If I am tempted now to make a foolish incursion into this perilous field, it is because there is one small detail of the story which I cannot remember having seen adequately discussed.
In 1908 Ettore Bugatti, who some years previously had been commissioned to design cars for the De Dietrich Company, built a car in his works at Cologne with a small overhead-camshaft 4-cylinder engine, which is usually known as the Type 10 and which so closely resembled the Isotta-Fraschinis which ran in the Grand Prix des Voiturettes earlier that year that many people, myself included, were tempted to suppose that Bugatti had also designed these Isotta-Fraschinis. Our erroneous conclusion was reinforced by the fact that in 1907 De Dietrich had acquired financial control of Isotta-Fraschini and it seemed probable enough that they had commissioned Bugatti to design a racing voiturette for their Italian associate. We know better now. We have Iearnt that the designer of the Isotta-Fraschinis was Cattaneo, who categorically declared that Bugatti had nothing to do with them. How then to explain the close similarity to them of the Type 10 Bugatti? It has stuck in the gullets of Bugatti enthusiasts to suppose that the great man was a copyist but they are happy to admit that he himself was the first to recognise the value of “observation”. Accordingly, or so I believe, the orthodox view is that Bugatti, only admiring what he could see of the little Isotta-Fraschinis, resolved to go home and himself build something very like them, which finally materialised as the Type 10. I might be able to believe this were it not for the fact that its engine dimensions were 62 x 100 mm. , When the organiser of the Coupe de / Auto decided to make provision for the use of 4-cylinder engines in their 1908 event, they fixed a bore limit for them of 65 mm. At this point, however, the ACF decided to get in on the act, with the organisation earlier in the year of a Grand Prix des Voiturettes, and for this, they decided, the bore limit for 4-cylinder engines should be not 65 mm but 62 mm. Why they reached this decision is obscure, since even a bore of 65 min was generally regarded as so small as to present special engineering problems, and by contrast with present-day practice whereby cylinder dimensions are apt to wander off into several places of decimals, it was unusual in the Edwardian period (although there are exceptions which prove the rule) to adjust them by intervals of less 5 min unless designers were forced to do so by the formula governing race entries. (The dimensions, for instance, so popular a few years later, for a 3-litre 4-cylinder engine of 80 x 149 mm would almost certainly have been 80 x 150 mm had not this minimally longer stroke not taken the capacity just over the limit.) Anyhow, for better or worse, entrants for the Grand Prix des Voiturettes had to be content with a bore of 62 mm, and the dimensions of the Isotta-Fraschini engines designed for it were 62 x 100 mm. It can hardly be a coincidence, surely, that the Type 10 Bugatti also used this curious bore. Nor can this similarity be readily explained by “observation” in the ordinary sense! Even to the eye of a Bugatti, I imagine, an engine would look much the same from the outside if the bore were, say, 60 mm, 62 mm or 65 mm. Nor, again, is there any evidence that Bugatti had any personal penchant for a figure of 62 mm when, a couple of years later, his Type 13 appeared as a development of the Type 10, the stroke remained at 100 mm but the bore was tidied up to 65 mm. I am personally forced to the conclusion, therefore, that when he built the Type 10, Bugatti was working trom Cattaneo’s drawings.
I do not think that, if this conclusion is accepted, Bugatti’s admirers ought to be unduly put out by it. The Isotta-Fraschini racing voiturettes had not been a great success. One of them managed eighth place in the ACF race, the first of the four-cylinder cars to finish, but none of these could keep up with the powerful single-cylinder racers which dominated the event. In the circumstances of the time this was hardly surprising. The only advantage that the four-cylinder engines could have had was their ability, deriving from a shorter stroke and lighter moving parts, to attain relatively high crankshaft speeds. But as at the time no crankshaft could be trusted at more than say 2,400 rpm, which could be attained by the single-cylinder Sizaire-Naudin, the potential advantage in this respect of the multi-cylinder engine remained purely theoretical. In consequence Isotta-Fraschini were discouraged and gave up motor racing. This was a pity, because if they had persevered until 1910 they, rather than Hispano-Suiza, might have been the first to win the Coupe de l’Auto with a four-cylinder engine and in any case it would have been interesting to see how their overhead camshaft design compared with the T-head layout used by the Spanish constructors. But if the Isotta-Fraschinis had failed as racing cars, there might be other applications for Cattaneo’s concept. In 1908 the motor industry was in the throes of a depression. Customers seemed to be unable to find the money for a large car of conventional type and manufacturers were forced to the conclusion that their only chance of survival lay in the ability to offer them a much cheaper voiturette. Small cars with hefty single-cylinder engines like the Sizaire-Naudin, however, were not everybody’s cup of tea. Starting these engines, for one thing, was something of a he-man’s job. By contrast swinging a small four-cylinder unit fitted with a decent starting-handle carried in proper bearings, was, at least by comparison, not much more trouble than winding a clock. If Isotta-Fraschini had lost interest in racing voiturettes, De Dietrich may well have wondered whether Cattaneo’s design might not be suitable for a handy little run-about. But the voiturette racers, like all proper racing cars, had presumably been built regardless of cost. What I believe Bugatti was doing when he built the Type 10 was seeing whether he could produce it at a price which would make it a commercial proposition. Perhaps the results were not too encouraging, if only because the engine was unnecessarily complicated for a cheap little run-about! At any rate De Dietrich, even if they had ever had a mind to pursue the matter, seem to have decided against it. Bugatti, on the other hand, went ahead on his own, and by the time he had perfected the Type 13 had done something much more original than perhaps he had in mind when he started: he had invented the small sports car. At the same time the idea of the run-about evidently stayed in his mind and finally took shape in the much simpler design, with a side-valve engine, used for the pre-1914 Bebe Peugeot, which may be regarded as the prototype of the post-war Quadriletto, the Austin Seven, the 5 CV Citroen and a host of other small cars. If Bugatti copied Cattaneo in 1908, he himself was to find plenty of imitators in later years. — Kent Karslake