by Kent Karslake
Two Single-Cylinder De Dion Boutons
I never miss a Vintage Sports Car Club event if I can help it. But on April 23rd last, I was what we call locally “down the country,” and the Minister of Fuel and Power, apparently, found that it would not fit in with his plans if I paid a flying visit to the Midlands. In consequence, the first I knew of what had happened at the Club’s Silverstone Speed Trials was when I read through the results, and I was correspondingly surprised to see that Mr. C. R. Abbott’s 1904 Mercédès was alleged to have made slowest time of the day, a performance which is by no means typical of that almost indecently skittish “ancestor.” The explanation, however, was an intriguing one. The Mercédès having proved at the last minute to be not available, Mr. Abbott had obtained permission to substitute for it a single-cylinder de Dion Bouton, and a time which had appeared on the sluggardly side for the Mercédès, immediately took on a very different complexion. Even if it was the slowest time of the day, it was obviously a very good time indeed for any single-cylinder motor car in existence, with the exception of some of these 1/2-litre projectiles which in any case are not eligible to run in the Edwardian class.
Knowing the sort of way in which Mr. Abbott is apt to renovate and turn out his cars, I conceived a lively desire to see this addition to his stable, and my ambition was realised at the beginning of July, when I attended the V.S.C.C. Rally at Madresfield. Mr. Abbott had driven down from London on his “single,” a distance of more than 100 miles; he was engaged, that afternoon, in performing on it some extraordinarily complicated evolutions designed by the organisers to perplex competitors; and he was proposing to drive back to London that evening, a proposition, I may add, which he duly solved with consummate address. As a motorist I was immensely intrigued by the obvious efficiency of this single-cylinder motor car; as a journalist I became avid to include it in the “Veteran Types” series in Motor Sport. When, moreover, the Editor suggested to me that I might combine a description of Mr. Abbott’s car with one of another single-cylinder de Dion of comparable age, belonging to Mr. A. F. Carlisle, my enthusiasm redoubled.
Considering the difficulty of finding a summer afternoon when several motoring enthusiasts are all free for an informal meeting, the necessary arrangements were concluded with a despatch that bore witness to the enthusiasm of the journalists concerned and the kindness of the owners of the cars. The plot was that I was to motor down with Mr. Abbott from his works near London to Mr. Carlisle’s house near Maidenhead, in the vicinity of which we could compare at our leisure the appearance, specification and performance of the two de Dions. The scheme worked to perfection, and in due course, on a rather sultry afternoon of late July, these two exceedingly intriguing veterans stood side by side for the delectation of the party and the Motor Sport photographer.
De Dion Bouton were, of course, not only among the pioneers of the single-cylinder engine, but the inventors, in this form, of the high-speed engine. Indeed, it was the experiments in this direction of M. Bouton, under the encouragement of the Comte de Dion, during the early nineties of the last century, which led to the rupture with their partner, M. Trépardoux, who was, first and last, an enthusiast for steamers. “To fight against steam is to fight against ourselves,” declared the intransigent Trépardoux, who thereupon walked out of the firm — and out of history. But de Dion and Bouton persisted; by 1895 they were making 3/4-h.p. single-cylinder petrol engines for tricycles, which ran at the absurd speed of 1,800 r.p.m., and before the end of the century they were making a 3 1/2-h.p. single-cylinder voiturette. By 1900 this had grown into a 4 1/2-h.p., by 1901 into a 6-h.p., and by 1902 into an 8-h.p., with the engine in front, instead of at the back under the seat. From a little runabout 3 1/2-h.p. two-seater, suitable for the marvellously dressed and highly emancipated chauffeuses of the nineteenth century, the single-cylinder de Dion had become quite a fast car. I presume, though I cannot exactly vouch for it, that it was this type of engine that powered the 9-h.p. de Dions which started in the voiturette class of Paris-Madrid. If so, these cars must have been among the fastest “singles” yet produced, for on one of them Holley averaged no less than 40.8 m.p.h. for the 342 miles from Paris to Bordeaux.
Moreover, from its very early days the firm had been prepared to manufacture engines for use by other people, and from the beginning of the century makers like Renault and Corre had been carrying all before them in the voiturette racing class with the help of the de Dion Banton single-cylinder engine. With the coming of the Coupe de l’Auto in 1905 the process was continued, and in the early events of the series, an enormous number of the competitors relied on de Dion engines. The development of the “single” proceeded apace. In 1907, automatic inlet valves, which hitherto had worked far better than they should, in view of the high crankshaft speeds attained, gave place to mechanical operation; and, the bore of single-cylinder engines being limited by the rules of the competition to 100 mm., the stroke was progressively increased, until in 1910 the long-stroke “single” reached its apotheosis with the de Dion engine of 100 by 300 mm. fitted to Collomb’s racing Corre.
By 1908 the process had reached the point where the stroke of the 100-mm. “single” was 160 mm., and de Dion Bouton decided to fit this powerful engine, with a capacity of 1,260-c.c., into a sporting chassis known as the “Type de Course.” As befitted this type of chassis, the bodywork usually provided was designed more with an eye to its racy appearance than to weather protection, and it is hardly surprising, therefore, that as these chassis, which retained their typical de Dion characteristics of longevity and economy, passed out of the hands of their original enthusiastic owners into those of the average soulless motorist, there was a tendency to scrap the original bodywork in favour of something a trifle cosier. As a crowning indignity, one of these chassis was burdened with a Morris-Cowley body before being relegated to a Hampshire scrap-heap; whence it was rescued by Mr. Carlisle, who must, one feels, have a particularly fine eye for a thoroughbred when he sees one. The Morris-Cowley body was thereupon returned where it belonged, and, with the aid of contemporary photographs, the new owner proceeded to reconstruct as pretty a sports two-seater of 1908 as any enthusiast could desire.
Apart from sowing their one wild oat in Paris-Madrid, Messrs. de Dion Bouton had never been very keen themselves about racing since the demise of the powerful steamers so keenly lamented by M. Trépardoux. As far as their small cars were concerned, the accent had always been on economy rather than speed, and I fancy that they may have been a trifle embarrassed about the raciness of the “‘Type de Course.” In any case, after making its debut in 1908, it seems to have disappeared from the market in about 1910. In the meantime, however, the long-stroke era was having its effect also on the 6-h.p. 90 mm. bore engine. Originally introduced in 1901, this was revived in 1905, with dimensions of 90 by 110 mm. It seems to have disappeared again in 1907, but in 1911 it reappeared, although now called 8 h.p., and while the bore was still 90 mm., the stroke had now grown to 150 mm., making the capacity 955-c.c. In a sense, I suppose, this long-stroke engine replaced that of the “Type de Course” — the stroke-bore ratio, at 1.66 to 1, was actually slightly greater — although it seems to have been used, believe it or not, among other things, to power Paris taxis. It was, in any case, the final flowering of the single-cylinder de Dion engine, of which the story had started soon after 1890. It lingered on into 1912, but by the end of that year, in the company’s own words, “public demand had changed entirely to the multi-cylinder engine type of car. Hence the single-cylinder models on which the fame of de Dion-Bouton vehicles had been built were absent from the 1913 catalogue . . . “
It was a chassis of this latter type, as my readers may have guessed, that Mr. Abbott had come across. As with the “Type de Course,” the bodywork he found on it was valueless, and, like Mr. Carlisle, he set about constructing a two-seater body which should combine a reasonable degree of gaiety with the spirit of 1911. As will be seen from the illustration, he succeeded to a remarkable degree, although his solution and Mr. Carlisle’s remain extraordinarily different. Mr. Abbott’s car is not a “Type de Course”; but apart from its performance, with which I propose to deal presently, its appearance, at once justifies our calling it a “Type de Sport.”
Having got the two de Dions lined up side-by-side we started with avidity to compare the details of their specifications. Both are painted French blue, but the “Type de Course” is a shade lighter than the “Type de Sport,” and the former has varnished, instead of painted, wooden wheels. When, in 1902, de Dion Bouton moved the engine to the front of their car, they enclosed it in what has come to be known as a Renault-type bonnet, a real bonnet, that is, hinged at the back, while the radiator tubes were ranged below it. On some models this arrangement lasted at least until 1906, but by that date it had already become the firm’s more general practice to enclose the radiator tubes in a shell forming the front of the bonnet, and this familiarly-shaped shell, in gleaming brass, is, of course, a feature of both the cars now in question. But while on the “Type de Course” the gilled tubes in it are arranged horizontally, on the “Type de Sport” they are vertical. Externally, the two engines do not vary greatly in appearance, although the “Type de Course” is just noticeably the larger. I suppose that if a manufacturer who was accustomed to multi-cylinder engines had decided to build a “single” with an L-head, he would probably have placed the valves on one side or the other. But de Dion Bouton started from the other end — with a “single” — and in the earlier examples the exhaust valve was placed at the front of the engine where it was in the most favourable position to keep cool, with the automatic inlet valve directly above it. When the latter came to be mechanically operated, it was placed by the side of the exhaust valve, and the single cam, mounted on the back of the half-time pinion, was made to operate both valves through rockers.
There is, however, an interesting point of difference between the two engines which does not immediately catch the eye, in that while the “Type de Course” has forced-feed lubrication, the “Type de Sport” has not. The surprise in this matter centres entirely on the “Type de Sport.” De Dion Bouton introduced forced-feed lubrication on their engines in 1903 and were exceedingly proud of the fact. Its presence on the “Type de Course,” is, therefore, just what you would expect. Why it was omitted from the “Type de Sport” is something of a mystery. According to my “Catalogue des Catalogues” the 90 by 150 mm. engine was fitted to two different chassis in 1911, the Type CW, which is called the “chassis fiacre,” and the Type CP, of which Mr. Abbott’s car is an example. Type CW, remarks the “Catalogue,” had forced-feed lubrication; with regard to Type CP, it is silent, which confirms that Type CP had not, and could thus be distinguished from Type CW. But why forced-feed lubrication should have been considered necessary on a taxi, used to chug about the streets of Paris, and not on a touring chassis, which might well be set to hare along the French routes nationales passes my comprehension. However, it seems to get on extremely well without it.
The early de Dion voiturettes were fitted, as a most characteristic feature, with a gearbox having constant-mesh pinions engaged, according to the speed required, by clutches. In 1905, however, when the firm started to build four-cylinder cars, this gearbox, which presumably proved to have disadvantages when more power was put through it, was abandoned except for the small cars, and in 1907, at the same time as automatic inlet valves were finally given up, sliding-pinion gearboxes were fitted to all models, with metal-to-metal clutches. They are fitted, therefore, to both our veterans; but whereas the “Type de Course” has two “baladeurs,” and a gear-lever working in a vertical gate, the “Type de Sport” has a single “baladeur,” and its gem-lever works on a quadrant.
It was, however, behind, or, to be quite accurate, beside, the gearbox that resided the most interesting feature of all of the early de Dion transmission. At least, that is the way it strikes one to-day, although the “de Dion drive” would appear as the merest curiosity, if it had not been revived on the racing Mercédès and thus forced into the forefront of contemporary thought. Mr. Laurence Pomeroy in another place (actually in two other places) has credited me with the suggestion that the so-called de Dion drive may really have owed its origin less to de Dion, or even Bouton, than to Trépardoux. As a matter of fact I did make this suggestion. I made it rather late at night; if it had been earlier in the day, I might have kept my own counsel, in the hope of a journalistic scoop. But although I had reached my conclusion after what seemed to me to be pretty profound inferential reasoning, I did not reach it as a result of such deep technical erudition as that which Mr. Pomeroy has been kind enough to attribute to me. Be that as it may, the “de Dion drive” was used on the nineteenth century steamers, and for many years it was exclusively used on the petrol cars as well. By about 1905, the firm had quite a number of imitators, including designers who played slight variations on this original theme; but after a short time these imitators gave up the idea, and everyone else seemed to think that it was so much better to have an unsprung final drive assembly that even de Dion Bouton began to waver. In 1911, for the first time, “de Dion drive” was abandoned on some models in favour of the more conventional system, and among these models was the single-cylinder, which, traditionally, should have been the last to retain it. Actually it was on the larger models that the firm stuck to it, right up to 1914 and even beyond, the latest recorded use of it being in 1916 on the Type GS, which was an eight-cylinder military chassis used for towing.
It can, therefore, still be seen in all its pristine elegance on the “Type de Course.” The principle on which it operates, at one time almost forgotten, is nowadays, probably, again pretty well known. Briefly, however, one may recall that the casing containing the gearbox, bevel gear and differential is rigidly bolted to a cross-member of the frame between the rear wheels, which are carried on a “dead” tubular axle curving round behind the gear casing. From the latter, the drive is taken to each back wheel by a transverse, double universally-jointed cardan shaft. Unsprung weight was thus reduced to a minimum, and about the only disadvantage of the system, I suppose, was that, like a good many other things that are good, it was relatively expensive. In any case, by the time the firm came to make the “Type de Sport,” the “de Dion drive” had been abandoned, and I must say that when it came to substituting a live axle for it, the makers made pretty heavy weather of it. The axle casing, to judge by outward appearances, would do justice to a lorry, and looks absurdly heavy for a single-cylinder voiturette. Moreover, the designer was obviously alarmed by the new problems with which he was confronted. In the “Type de Course,” and all earlier cars, he had successfully disposed of the torque problem by bolting the final drive assembly firmly to the frame. Now that it was, so to speak, floating about in midair, he felt that he must take adequate steps to see that it did not turn over backwards, and accordingly, at the expense of more weight, he enclosed the propellor-shaft in a torque tube. But for some reason he felt that this tube should serve the purpose which its name implies, and none other, so that he refrained from putting the thrust through it. On the “Type de Course,” the back springs are shackled at their rear ends only, and the drive is taken through the front half. This was all very well when the springs had only to take care of the wheels and the “dead” axle tube, but with an unsprung live rear axle this was evidently felt to be improper, the rear springs of the “Type de Sport” were shackled at both ends, and the drive taken through a hefty system of triangulated radius rods. This last arrangement, however, was too much for Mr. Abbott, who, when reconstructing the car, discarded the radius rods and substituted pivots for the forward shackles so that the drive now goes through the springs. To judge by results, Mr. Abbott has shown that M. Bouton, or whoever it was, with his radius rods, was making much ado about nothing.
It is time, in any case, that we started to do a bit of judging by results, and closed this dissertation on the history of de Dion Bouton and the specifications of the cars. Mr. Abbott drove me down in his car from Acton to Maidenhead, and I thus first made the acquaintance of the “Type de Sport.” In view of the splash lubrication, we started by giving the crankcase rather a liberal supply of oil. This operation, which is performed by the passenger, consists of drawing on the handle of a plunger pump situated on the floor under the scuttle, turning the handle through 90 degrees, and depressing it again. If, after that, the engine does not smoke, you repeat the process. Perhaps we repeated it when the engine did smoke; but that had nothing to do with the fact that, five minutes after the start, with a bang that I thought was merely a backfire, one of the back tyres blew off the rim. Fortunately, as it was a hot afternoon, the tyre had chosen to burst at a convenient spot, where we could draw the car off the road and into the grateful shade under a tree. Even so, the insertion of another tube and its inflation with a foot pump took some time. We moved on to a garage, where we took on some more air under ready-made pressure, and then the plug, tired of all this stopping and starting with an overfull sump, decided to oil up. Mr. Abbott was inclined to be critical, saying that no such fickleness had been shown on the journey to Madresfield and back. With a clean plug, the engine restarted and the “Type de Sport” went like a bird for the rest of the afternoon; but by this time we were late, and I dissuaded Mr. Abbott, during the run to Maidenhead, from relinquishing the wheel to a less competent driver.
Thus it was that the “Type de Course” was the first of the two cars that I drove; and hardly had Mr. Carlisle handed it over to me on a private road near his house, than I fell completely in love with it. For first speed, you press the gear-lever down through the vertical gate, and pull it back towards you; if you keep it pressed down, and push it forward, you select reverse. If, on the other hand, you push it forward out of first without depressing the top of it, it springs upwards when it reaches the gate, and, on the upper selector, goes forward into second. For top, of course, you pull it straight back. In practice, I found this gearchange quite delightful. The clutch does drag a bit, and in spite of an extemporary clutch-stop devised by the owner, it is not easy either to engage first silently, or to make clean upward changes. But the change down from top to second is delightful, and the single-cylinder engine, in spite of its heavy flywheel, is responsive enough to the throttle to enable the change to be made in the modern, rather than the contemporary, manner.
The high-geared steering is as satisfactory as the gear-change, and, with the fairly high seating position, low scuttle and bonnet and absence of valances, one can not only see both front wings but both front wheels. The added pleasure that this ability imparts to driving is something of which the average motorist nowadays probably has no conception. Indeed, those persons who style themselves enthusiasts and write to the motor papers with eulogies of present-day cars, should really be made to drive something like the “Type de Course” in order just to show them how little they know about their subject. Moreover, I do not think that it is just imagination — because one knows that the de Dion drive is there — which inspires the conviction that the car has marked directional stability. It handles in such a fashion that one feels that it would be entirely satisfactory as a high-speed motor car. The only possible disappointment with regard to it is that there is really no scope for putting the matter to the test; for the “Type de Course” is hardly as fast as its type-name would seem to suggest. Its cruising speed, in its present tune, is in the thirties, and about 40 m.p.h. appears to be its comfortable maximum. On June 26th, 1909, the Autocar published some impressions of the “Type de Course” by its well-known contributor “Runabout,” who declared that “1,800 revolutions per minute is a very conservative estimate of its engine speed, and at that speed, with a seventeen-tooth bevel driving a fifty-eight-tooth crown wheel, it does over seventy kilometres an hour”; and he went on to say that the car had a maximum speed of “at least eighty kilometres an hour.”
I can well believe it. But on Mr. Carlisle’s car, a fifteen-tooth bevel drives a sixty-one-tooth crown wheel, so that, at 1,800 r.p.m., instead of doing 70 k.p.h. (43.5 m.p.h.) it is doing 58.6 k.p.h. (36.5 m.p.h.); and the equivalent of a maximum of 80 k.p.h. (50 m.p.h.) is say 42 m.p.h. Clearly, in fact, though it hardly feels undergeared when one is driving it, Mr. Carlisle’s car would pull an appreciably higher top — and should apparently do it quite comfortably, as in 1909 “Runabout’s” car “managed about half of Fitzjohn’s Avenue in top, before calling for a change.” But in the meantime, it is perhaps just as pleasant to handle a machine with the feel of a racing car at 35 m.p.h., as it would be if it cruised 10 miles an hour faster.
Driving Mr. Abbott’s car on the way back from Maidenhead provided a most interesting contrast. After the “Type de Course,” one rather missed, I must admit, the vertical gate, for the gearchange quadrant is not even provided with notches to mark the several speeds, so that one has to “feel one’s gears” with a certain skill. Indeed, after moving off the first time, I ham-handedly went from first straight through second into top, which was a tribute to my (quite fortuitous) timing of the change, and a reproof to my handling of it. This improved with a little practice, but, apart from this first fluke, I found that, as with most gear-changes of this type and date, it was easier to get satisfactory results when changing down than up.
Like the “Type de Course,” the “Type de Sport” has delightfully high-geared and accurate steering, but it needs rather more holding to the desired direction than does the “Type de Course,” which may be due to the live axle or to the rather shorter wheelbase 6 ft. 10 1/2 in., against 7 ft. 5 1/2 in. Indeed, it gives one the impression of being a tiny little car, and, unlike the “Type de Course,” one sits in, rather than on it, a fact which we appreciated to the full on the way down to Maidenhead, when we ran into a shower of rain, and found that little more than our heads and shoulders were getting wet.
But the outstanding feature of the “Type de Sport” is the bomb-like manner of its going. In the number of Motor Sport for August, 1946, “Baladeur” quoted at some length from an article on single-cylinder engines by M. Salomon, which was published in the French paper Omnia, in 1925. In this article M. Salomon declared that a single-cylinder engine of 940 c.c., running at 1,800 r.p.m. would give 11 h.p., and drive a voiturette at 50 k.p.h. (say, 32 m.p.h.); but that if you wanted 50 m.p.h., you must either have 1,900 c.c., or much higher engine speed, in either of which cases, with a single-cylinder engine, “the trepidations would be excessive.” With all due respect to M. Salomon, the “Type de Sport” seems to me to have effectively disposed of this thesis. In so doing it has, I suppose, perhaps owed more to Mr. Abbott than to either the Marquis de Dion or M. Bouton. Mr. Abbott has encouraged his engine to rev, by considerably advancing the ignition, and has enabled it to respond to such encouragement by giving it an aluminium piston. As a result the car will cruise happily at a genuine 40 m.p.h., and must have a maximum of very close to 50 m.p.h. — the owner himself puts it at about 47 m.p.h. At this road speed, with a top-gear ratio of 4.2 to 1 and 760 by 90mm. tyres, the crankshaft speed must be well up in the two thousands. But while the single-cylinder engine gives some pleasantly hearty thumps when under heavy load, as when accelerating, there are quite definitely no “excessive trepidations” either when it is idling, or when it is running at its comfortable cruising speed. At 40 m.p.h. one must listen quite attentively to the exhaust in order to realise that there is a single-cylinder engine under the bonnet.
Comparisons are proverbially odious, but sometimes, nevertheless, instructive; and it seems particularly interesting to compare the “Type de Sport” with the nearly contemporary four-cylinder 850-c.c. Bébé Peugeot, and even with the 750-c.c. Austin Seven of a decade later. The de Dion engine is obviously simpler and at least as economical; it provides approximately the same cruising speed; and its extra power “low down” would make up, for many people, for what it lacks in smoothness under load. Indeed, after driving these two delectable “singles,” one is forced to the conclusion that when, in 1912, “public demand changed entirely to the multi-cylinder engine type of car,” the public showed itself to be just as wrong in its opinions as the public usually is.
Photographs appearing in this article are Motor Sport copyright.