By ” BALADEUR.”
DURING September, 1934, a procession of motor cars, all at least thirty years old, might have been theca] n tem d traversing the road from Paris to licitien. They were celebrating, actually, no less an anniversary than the fortieth of the modern motor car. For in July, 1894, was organised the first competition for horseless carriages over this same road along the valley of the Seine.
I do not propose on the present occasion to describe the events of that epoch making original run. Its anniversary has passed almost unnoticed in England, where, forty years ago, the difference between a motor car and a traction engine was not appreciated ; and lest the fact that 1934 was an anniversary be altogether forgotten in this country, I propose to lay bare to von the history of the motor car during these four decades. The Editor, however, informs me that he cannot include an over-size hook in one numbsr of Morois Samar, and thus instead of a narrative I shall fall bock on a series of four tableaux, consisting of the racing cars of 1894, 1904, 1914 and 1924.
The first prizta in the ” Concours des Voitures sans Chevaux ” which consisted of the run from Paris to Rouen, was divided between the firms of Peugeot and Panhard et Lt.VASSOT. The latter firm had run four cars, which represented the result of years of research. They were fitted with the Daimler engine, which, invented by the famous German engineer, had first been applied to the motor car by Messieurs Panhard et Levassor. This engine had Iwo cylinders, arranged in a narrow V. at an angle of 15° to each other. In the case of two of the cars the engine had a bore and stroke of 75 by 120 mm., giving a capacity of 1,058 c.c. ; while the other two cars, which were driven by MM. Panhard and Levassor themselves, had engines of a more recent type, with a bore and stroke of 75 by 140 mm. (1,23.5 c.c.). What was then regarded as the outstanding feature of the Daimler engine was the phenomenal speed at which it ran ; it developed 3i h.p. at no less than 750 r.p.m.
At first sight it is striking that when the internal combustion engine as applied to a vehicle first appears in history it should have been so small. The power developed, however, was presumably considered ample, although by the time it was delivered at the road wheels it could not have replaced very many horses. Nevertheless, the cars fitted with it averaged about 10 m.p.h. for the 80 miles, which by horse-drawn standards was good going. What is in reality more surprising is the bore-stroke ratio. It is very curious that this high-speed engine should have been given such a long stroke. The piston speed was undoubtedly i)lienomenal compared with that of the contemporary Benz engine, which, although it (nth, ran at Me spans was a ” square ” single, with a bore and stroke of 110 in ins.
But to return to our Panhard. The connecting rods of the two pistons had their big ends on the same throw of the crankshaft, the webs of which acted as flywheels. The inlet valves were situated in the head and were suction operated. The exhaust valves, immediately below them, were operated by rods, the lower ends of
which ran alternatively in two grooves cut in one of the flywheels. One of these grooves was concentric with the crankshaft, and the rod when running in it, missed the tappet of the exhaust valve. At the end of the revolution, however, the rod passed into the second, and eccentric groove by which it Was lifted Sufficiently to hit the tappet.
Such things as two-to-one wheels and camshafts are NOT essentials of a poppet valve engine !
A centrifugal governor, once the engine exceeded a certain speed, operated on a lever, which bore against the exhaust valve operating rods and caused them to miss the valves. On three of the cars the carburettors were of the surface type, as patented by Gottlieb Daimler himself in 1885,in which a float kept the petrol at the correct level at the bottom of a chimney, down which the air rushed, bubbled through the petrol and into the induction pipe. LeYassor’s car, however, had a, jet carburettor, patented by Daimler’s great collaborator, Wilhelm Maybach.
In the case of all the cars ignition was by means. of platinum tubes, of which the open ends were screwed into the cylinder, and the closed ends were heated by petrol burners. On each compression stroke gas was forted into these tubes and ignited on reaching their red-het ends.
From the engine the drive was through a double cone clutch to the. change speed gear—hardly a gear-box, for it was not enclosed—but which worked on the sliding pinion principle, which is not yet quite dead. Behind this :gearing was a bevel gear driving a countershaft, final drive being by side chains to the largo back wheels, which were shod with iron tyres. The front wheels were smaller, had solid rubber tyres, and were steered on the Ackerman principle, controlled by a singlegrip tiller. Drums on the back wheels carried brake bands operated by a pedal, while a lever worked spoon brakes on the back tyres. The cars were slung on semielliptic springs all round, and the engines were Cooled by water, which, however, passed through no form of radiator.
Famous Panhard et Levassor of 1894, you sound a bit crude to the modern critic, but yon are hilly recognisable as the ancestor of the motor .car of to-day!
The curtain falls, and is again rung up, ten years later. The racing car of 1904 is the 80 lap. Richard Brasier, which, with Leon Thery as its driver, won the Gordon Bennett race in Germany. Alas 1 have met enthusiastic motorists of to-day who have never heard of the marque—sic transit ! I must confess that I do not know myself what has become of the ChaigneauBrasier which carried on one-half of the tradition. But I am convinced that everyone of my readers has travelled in a Georges Richard though, low be it spoken, they only realised that it was a Unic taxi-cab !
That, however, is by the way. Our racer of 1904 was rated at 80 h.p., or nearly 23 times as much as the 1894 Panhard et Levassor. In those ten years the power of the most successful racing car had advanced as follows :-1895, 4 h.p. ; 1896, 8 h.p. ; 1897, 6 h.p. ; 1898, 8 h.p. ; 1899, 16 h.p. ; 1900, 24 h.p. ; 1901, 60 h.p. ; 1902, 16 h.p. ; 1903, 70 h.p. The result had been achieved largely by increasing the size Of the engine. The RichardBrasier, in the. first place, had four cylinders instead of two, the increase in the number having been introduced successfully in 1898. Since then, by slow degrees, the size of the cylinders had been increased until our Richard-Brasier had a bore and stroke of 150 by 140 mm. (9,896 c.c.). One may note in passing that engine speed had by now been pushed up to about 1,500 r,p.m., and the stroke remained the same as in the DaimlerPanhard engine of 1904, while the bore had been doubled, The power developed was about 110 lap.
Both the inlet and the exhaust valves were now mechanically operated, although the automatic inlet valve had not disappeared even from racing cars in 1904, and were placed at the side of the vertical cylinders. There was an ordinary camshaft, taking the place of all that ingenuity of grooves in the flywheel. The engine was still fitted with a• centrifugal governor, but the carburettor, of course, was of the jet type. Most important change of all, perhaps, as far as the engine was concerned, ignition was new by means of a magneto — or a ” magneto-electric machine ” as it might still have been called without undue pedantry. It was only since the turn of the century that the accumulator and coil form of electric ignition had really ousted the platinum tube from popular favour, although Benz had used the former since the earliest times. In 1900 Panhard et Levassor had used electric ignition on their racing cars for the first time, but still kept the oldfashioned well-proved burners and tubes as a stand-by. It was only in this year 1904 that the coil was being generally abandoned on racing cars, although Mors racers had been fitted with low-tension magnetos since the early days of 1897.
From the engine, which Was where
Levassor had originally placed it, at the front of the chassis, the drive was still through a leather cone clutch, which, however, was now fitted with locking pins to :stand up to the tremendous torque of 80 lap. In its essentials the gearbox was unchanged from M. Levassor’s original design, although it was now enclosed in an actual ” box.” The Richard-Brasier of 1904 had three speeds ; in 1894 two of the Panhards also had three, the ethers four. Behind the gearbox was still a countershaft, with final drive by side chains, still generally considered essential for a powerful racing car. The wheels were now of equal sizes, and, all-important change, shod with pneumatic tyres. Not for nothing had the Michelin brothers, picking their way to avoid sharp stones, driven their car, equipped with the lunatic new invention, in the race from Paris to Bordeaux in 1895. A couple of years
later pneumatic tyres had become an essential of anything which laid claim to being a fast car.
Steering was still on the same principle, but Thery gripped a wheel where Levassor had clung to a tiller. It was the death of the latter in 1897, as a result of an accident the year before, when the tiller of his car had been wrenched from his hands, which had sounded the death-knell of this form of steering. The brakes were still on drums on the back wheels in 1904, but the old tyre brakes, of course, had gone. Springs, still semi-elliptic, but now, as a great innovation, controlled by shockabsorbers. The idea had been first applied to racing cars by Mors in 1902, but it had not been generally adopted, and much of the success of the Richard-Brasier may be ascribed to this feature.
Finally, the cooling water for the engine now passed through a gilled-tube radiator. It was in 1897 that the Panhard et Levassors had first featured this fitting, but then it was hung below the body at the back of the car. Now it wasp fitted in the ” conventional” position at the front.
The Richard-Brasier of 1904, which was capable of about 90 m.p.h., certainly displayed many advances on the Panhard et Levassor of 1894. What would the next decade bring forth ?
Another Ten Years.
In 1914 the French Grand Prix at Lyons, then the race of the year, was won by a Mercedes. It is not this car which I propose now to describe, however, for the Peugeot which fought with it so epic a battle, was in the light of later knowledge, in many ways more advanced in design. The Peugeot’s engine was still a 4-cylinder, but the rules for the race now limited its capacity to 41 litres. Its dimensions, therefore, were 96 by 168 mm., and the capacity 4,464 c.c., or considerably less than half that of the Richard-Brasier. Observe, however, what has happened. The bore has been decreased from 150 to 92 mm., but the stroke has gone up from 140 to 168 mm. This, surely, is curious. When its size is limited the only way to increase the effective capacity of an engine (assuming that it can be perfectly filled with gas) is to increase the crankshaft speed, and incidentally piston speed, so that obviously, on the face of it, to ease this piston speed problem, you want a short stroke.
But in 1908 it was the bore only of the engines for the Grand Prix which had been limited. The same rule applied to the Coupe de l’Auto races of 1909, 1910 and 1911. In 1913 the Grand Prix had been run under a fuel consumption limit, which again tends towards long strokes. This feature of the 1914 engine was to some extent traditional.
In spite of it crankshaft speed had certainly gone up in the ten years. The Peugeot engine, as we have seen, was less than half the size of that of the RichardBrasier, yet it developed, almost exactly the same power, and this had been rendered possible by increasing its speed of rotation to 2,600 r.p.m. Obviously the difficulty of filling the cylinders when the engine was runing at this prodigious speed had introduced all
sorts of problems. Fiat, probably, had been the first to realise the desirability for a racing engine of a hemispherical cylinder head, and in 1905 the Italian engines were equipped with overhead valves at 45° to the vertical, operated by push-rods and rockers. In 1908 Bayard-Clement, had improved on this by using an overhead camshaft. The Peugeot of 1914 had two overhead camshafts and four valves per cylinder, with the sparking plug in the centre of the cylinder head. The carburettor used may be said to show only minor changes. Ignition was now by a high-tension magneto instead of the lowtension machine, with the make-andbreak in the cylinders as used on the Richard-Brasier.
A Revolutionary Innovation.
The drive was from the engine and was still taken through a leather cone clutch to a gearbox, which, however, now gave four forward speeds. Behind it, however, was now a propeller shaft, open, with two universal joints. None of the Grand Prix cars in 1914 were still fitted with chain drive, but lest you should think that it had been discarded years before 110 h.p. was extracted from 41litres, it is as well to point out that as late as 1913 :Mercedes had sent cars with final drive by side chains to the Automobile Club de l’Ouest’s Grand Prix de France, at le Mans. By 1914, however, all the other racers, as well as the Peugeot, were adding unsprung weight to their back axles in the form of bevel gears and differentials. Springs, incidentally, were still semi-elliptic all round, and the shock absorbers used by Richard-Brasier had come to stay.
The Peugeot, however, contained an innovation of the utmost importance. The hand lever still operated brakes in drums on the back wheels, but the footoperated brakes were now on the front ones. The idea was by no means new—it had been tried on touring cars, and notably the Atgyll, considerably earlier. It was, however, the first appearance of fourwheel brakes on a serious racing car, and it was destined to cause a motoring revolution.
Finally, before we leave the Peugeot, let us note that its body was finished at the back in a full stream-lined tail, terminating in a blunt point. This question was becoming of importance, for the cars were capable of some 110 m.p.h.
Ten Years Ago.
In considering the progress made during the ten years from 1914 to 1924, it is necessary to make allowances for the War, and to realise that after the Peugeot no new racing cars were built in Europe until 1919. In some ways, therefore, the changes of this period may be said to have come about in live, rather than ten years. During this period the whole effort of designers of racing engines had been concentrated on volumetric efficiency. For the 1924 Grand Prix, which, like that of 1914 was run at Lyons, the limit of engine size was fixedat 2-litres. The engine of the winning Alfa-Romeo was thus less than half the size of the Peugeot, but in the intervening period the designer had amply proved that he could beat the framer of racing rules. In spite of its comparatively diminutive
size the Alfa-Romeo engine developed 140 h.p., or considerably more than that of the Peugeot. How had this been done ? With the static dimensions of his engine limited, the designer had had to study the dynamics of the question. In other words he had had to increase crankshaft speed. In order to do this he demanded light reciprocating parts, and had sought them by splitting up his power chambers. Although its total size was halved, the Alfa-Romeo had double the number of cylinders. Eight of them, arranged -in line, had each a bore and stroke of 61 by 85 rams., giving a total capacity of 1,986 c.c. The valves, like those of the Peugeot, were inclined in the head, and operated by two overhead camshafts, which, however, were now driven by a vertical shaft instead of by a chain of gear wheels. Further study of cylinder heads had
induced the designer to limit himself to two valves per cylinder. The sparking plugs, situated between them, were still fired by a single magneto.
The difficulty of completely filling the cylinders at really high engine speed, however, had called for revolutionary measures. From the earliest times the gas had been aspired with the help of atmospheric pressure. At the high engine speeds now sought after this pressure was found to be inadequate. Designers had decided to pump the gas in with a supercharger. The idea was not really new. Marc Birkigt had played with the idea on the .Hispano-Suiza in 1912. Mercedes had already begun to use it on touring cars. Fiat had used it in the Grand Prix the year before, and it had proved a dangerous experiment. The Alfa-Romeo was among the first successful supercharged racing cars.
As a result of all this the engines attained no less a speed than 5,500 r.p.m.
The Final Picture.
Design during the decade succeeding the birth of the Peugeot had concentrated on the engine, while chassis really showed only detail changes. In large measure, doubtless, this was due to the fact that in the gap of the war years, while motor cars were neglected, experiments continued to be made with aero-engines—-the straighteight, for instance, was perfected for use in the air.
The Alfa-Romeo’s clutch was of the multiple disc type, instead of a leather cone, and the 4-speed gearbox was built up in unit with the engine. Unsprung weight, too, had again been increased by enclosing the propellor shaft in a torque tube, thus saving another universal joint. Springs were still semi-elliptic all round, and the brakes on all four wheels. The streamline tail, too, had been just slightly developed, except, incidentally, in the case of the car driven by Aseari, who preferred a stub tail in order to carry a spare wheel. And what of 1934? I do not propose to describe in detail last season’s racing cars, which the majority of my readers probably know as well as, or better than I, bemused by thinking of the racing cars of long ago, (Continued on p. 104) do. I will content myself, therefore, with touching on just one or two salient features of the Auto-Union. Its engine, at the end of the season, was a and developed 300 h.p. at 6,000 r.p.m. Nothing very remarkable in that—it would be possible to-day to get this power out of an engine of half the size, and there are plenty of engines about which will exceed 6,000 r.p.m. It is true the Auto-Union motor had 16 cylinders, but this was because its shape thus suited streamlining more than for any search after engine efficiency ; and it was so beautifully streamlined that the engine had even been ousted from where Levassor put it—at the front of the car—in order to fit in with the scheme. Partly as a result of this the cars were tremendously fast—they regularly attained 180 m.p.h. in road races, and their total weight was under 750 kilos 1 The design, even more than a triumph of stream
lining, was a triumph of road-holding. In order to attain this the designer had had to discard the form of suspension used since Levassor’s day, and spring each wheel separately.
It was as big a revolution as electric ignition, front wheel brakes, or the superchargers. Only a year or two ago I was of the opinion that racing car design was standing still ; 1934 has at least shown me that I was wrong.