Sooner or later, I suppose, every commentator on the sporting aspect of motoring succumbs to the temptation to discourse upon racing rules, This involves expressing opinions, which time almost invariably proves to be erroneous, if not downright wrong-headed. Being of a cowardly nature, therefore, I have hitherto been almost alone in resisting the temptation, contenting myself instead with drawing attention to the errors of other commentators in the past. Unfortunately, however, while this policy paid handsome dividends twenty years ago, when all knowledge of the past was a safely neglected subject, the subsequent enthusiasm for it engendered by such inquisitive institutions as the Veteran Car Club and the Vintage Sports Car Club has lately resulted in a series of raps over the knuckles reminiscent of nothing so much as a history class at school, so that if my ignorance is going to be shown up anyhow, it might just as well, it seems to me, be shown up over the technicalities of racing rules as over any other subject.
Having said which, I consider myself at liberty, subject always, of course, to the possible intrusion of the Editorial blue pencil, to say that in my opinion this year’s Grand Prix regulations, which limit supercharged engines to 1,500 c.c. and unblown engines to 4,500 c.c., are about as wet as they well could be. And, in defence of this opinion, I propose to go back about twenty years — to that halcyon age, in fact, when “Baladeur’s” word went!
Towards the end of 1925, M. Louis Delage electrified the Automobile Club de France by announcing that he would not run his cars in the forthcoming season’s races. As his 12-cylinder 2-litre racers had just won the Grand Prix for France for the first time since 1913, the announcement naturally came as something of a shock. The whole trouble, however, had really arisen on account of the supercharger. Fiat had been the first to use it, in the Grand Prix in 1923, but as the enterprising Italians had succeeded in bursting their racers’ engines as a consequence of it, nobody greatly objected. The next year, however, Alfa-Romeo had not only used a blower, but had won the race, and that was quite a different matter. German cars were not “invited” to participate in French races in those days, but the Targa Florio had shown that Mercédès were keenly interested in superchargers, and if there had been any Grand Prix Mercédès it was practically certain that they would have been fitted with them. Perhaps French designers had a foreboding as long ago as that that the Germans and their Italian friends were as much interested in aero-engines as in racing cars. In any case they said of the supercharger that its use constituted an unfair infringement of capacity regulations. It certainly did represent an ingenious means of getting round them; but the question as to whether it was unfair or not was clearly one for the A.C.F., and the A.C.F. apparently decided that it wasn’t. In spite of repeated protests from its opponents, the Club firmly refused to ban the supercharger; and Delage having, with others, equally firmly refused to use it in 1924, was obliged to adopt it in order to score his win in 1925.
His contention at the end of the year, however, was that under the existing regulations the 2-litre racers had proved themselves too fast for more than about half-a-dozen men to handle with safety and that the 1,500-c.c. cars of 1926 promised to be nearly, if not quite, as fast. As a forecast, it proved very largely justified. The 1925 2-litre developed 180 h.p., and by 1927, after it had overcome its teething troubles, the 1,500-c.c. straight-eight was giving over 150 h.p., which must have propelled this lower, better-streamlined car very nearly as fast as its elder brother. For, of course, Louis Delage did not make good his-1925 threat to abandon racing, but went on to win a second Grand Prix in 1927.
But he had made his protest, and if the A.C.F. ignored it, it was doubtless because it was bent on pursuing a consistent policy. To Réné de Knyff, who in those days was in charge of such matters, the whole thing was doubtless seen in its historical perspective. When first designers sought to make racing cars faster, they naturally enough did so by increasing the size of the engine. The Panhard et Levassor which won the Paris-Bordeaux-Paris race of 1895 had a 2-cylinder engine with a bore and stroke of 80 by 120 mm. By the next year two more cylinders, still of the same size, had been added for Paris-Marseilles; the 16-h.p. 4-cylinder for the Tour de France of 1899 had dimensions of 100 by 140 mm.; and thereafter, while the stroke remained the same, the bore was increased, until by 1901 it had reached 130 mm. Finally, in 1902, the process reached its logical conclusion with the appearance of the 70-h.p. model, with a bore and stroke of 160 by 170 mm.
It was checked that same year by the imposition of the 1,000-kilogram weight limit, which made it necessary to get more power out of an engine of given size instead of merely enlarging it. The problem was met by the more progressive designers by adopting mechanically-operated inlet valves and increasing engine speed. Piston speed was now the limiting factor and the short-stroke engine became the order of the day. In 1895 the stroke-bore ratio of the Panhard engine had been 1.5 to 1; its subsequent variations were as follows: 1899, 16-h.p., 1.4 to 1; 1900, 20-h.p., 1.27 to 1; 1901, 40-h.p., 1.08 to 1; 1902, 70-h.p., 1.06 to 1; 1904, 90-h.p., 1 to 1; 1906, 130-h.p., 0.92 to 1.
Engine speeds had now got up to about 1,500 r.p.m., and the organisers of the Grand Prix began to take alarm at their extravagance; for 1907 a fuel consumption limit was imposed. It was, however, sufficiently generous that it did not have much effect. Panhard, admittedly, went back to the 90-h.p. 170 by 170-mm. engine of 1904, but Panhard had long ceased to be in the van of progress, and both Renault, who had won in 1906, and Fiat, who was to win in 1907, stuck to the same engine dimensions as they had used the year before. Big-car racing, in any case, was about to suffer an eclipse; the centre of technical interest had by now shifted to the Voiturettes.
The organisers of the Coupe de l’Auto race, working on the then generally accepted assumption that piston speed was the limiting factor in extracting power from an engine of a given size, very reasonably decided after the first year to limit the bore and leave designers the choice of running a short-stroke engine fast or a long-stroke engine slowly. Whether as a result of accident or acumen, the Sizaire brothers, who were responsible for the Sizaire et Naudin which won the first race in 1906, had decided upon a “square” engine, a single-cylinder of 120 by 120-mm. bore and stroke, which turned at 2,000 r.p.m., put up a piston speed of 10 metres a second and developed 18 h.p., or 13.2 per litre, with a compression ratio of 4.2 to 1. For 1907, therefore, the organisers decided to limit the bore to 100 mm. and see whether designers would increase the stroke or the crankshaft speed. The Sizaires, being nothing if not enterprising, did both. The stroke was increased to 150 mm., the crankshaft speed to 2,400 r.p.m., the piston speed to 12 metres per second, the compression ratio to 4.5 to 1, and the output to 22 or 18.6 per litre. The stroke versus engine-speed dilemma, in fact, was not solved until 1908 — and then wholeheartedly in favour of the stroke, the Sizaire engine for that year maintaining its revs. at 2,400 r.p.m., advancing its stroke to 250 mm., its piston speed to 20 metres per second, the compression ratio to 5 to 1, and output to 42 h.p. or 21.4 per litre. By comparison, the relatively high-speed (2,800 r.p.m.), short-stroke (160-mm.) de Dion engine with which the winning Delage was fitted, developed a mere 28 h.p.
For the moment a piston speed of 20 metres per second seemed to be about the maximum obtainable (I wonder whether it has since been materially exceeded?), and, in order to get higher crankshaft speed it was evident that a multi-cylinder engine was needed. The winning Hispano-Suiza of 1910 was a 4-cylinder of 65 by 200 mm. (2,653 c.c.) which developed 60 h.p., or 22.2 h.p. per litre, at about 3,000 r.p.m., the piston speed being again 20 metres per second, and the figures in many ways curiously similar to those of the 1908 Sizaire. By way of comparison, the 2 1/2-litre Peugeot which was built for the 1914 race and which won the Targa Florio in 1919, had a bore and stroke of 75 by 140 mm. (2,472 c.c.); but in spite of the relatively short stroke, the crankshaft speed was no higher, piston speed therefore was lower, and yet, thanks to overhead valves and the combustion chamber which they permitted, the output from a slightly smaller engine had gone up from 60 to 80 h.p., equal to 32.4 h.p. per litre.
By 1921 its designer, M. Henry, had produced the 2-litre Ballot engine on extremely similar lines, and putting up crankshaft speed to 3,400 r.p.m. had maintained output at 80 h.p., or 40 h.p. per litre. Three years later, in 1924, Delage, by using 12 cylinders instead of four and putting crankshaft speed up further had got nearly 50 per cent. more power, with a figure of 116 h.p.; but in the meantime the Italians had introduced the supercharger, the 1923 Fiat had developed 118 h.p., and by 1925 Delage himself, by using a blower, was getting 180 h.p., or more than twice the 1921 Ballot figure, from a 2-litre engine. No wonder the A.C.F. wanted to go on with the fascinating story. No wonder they wanted to see 1,500-c.c. racing cars developing 100 h.p. per litre in 1926. The curious thing is that they refused to see that the way to meet M. Delage’s complaints was to introduce the 500-c.c. capacity limit, over 20 years ago!
Perhaps, however, their obtuseness was just as well. During the past twenty years engines, as shown by our lightning sketch, had undergone an amazing development. The 1,500-c.c. power units of 1926-27, with their 150 h.p., were developing more power than the 120 h.p. of, say, the 10-litre Richard-Brasier of 1904-1905, the last days of the Gordon-Bennett. In addition, racing had admittedly developed front-wheel brakes; but, by comparison with the engine, the chassis during the twenty years before 1926 had been neglected.
It seems to be part of the logic of motor-racing that when any trend has been pursued too far, interest in racing of that particular type falls off. Thus it was at the end of the 1920’s; and however interesting the A.C.F. may have thought it would be to pursue the capacity regulation and thus continue engine development, racing died as it had done in 1909 for lack of entries. In order that it might enjoy the revival of the 1930’s, the limitation upon engine size had to be abandoned. Almost immediately manufacturers returned joyfully to the fray. Crankshaft speeds came down, from the 7,500 r.p.m. level attained by the 1,500-c.c. engines, to about 5,500 r.p.m.; but in spite of the fact that M. Delage had been alarmed at the prospect of 150 h.p. in 1925, output went up, from the 190 h.p. of the 2,300-c.c. Alfa-Romeo of 1931, via the 300 h.p. of the 4-wheel-drive 5-litre Bugatti of 1932, until racing engines were developing 500 h.p. or more. The return to the weight limit, abandoned in 1906, did little or nothing to check the increase in the potency of the machinery with which the German and Italian racing cars of the 1930’s were provided. One thing only became of importance now — to make a large engine and to make it light.
Frankly, I think we learnt mighty little about engines during the period 1927-1939. But if M. Delage thought that the use of 500 h.p. turned races into nothing but a test of driving skill, I think, on the contrary, that, with the utmost respect, he was wrong. For if the racing engine of 1939 had very little to teach its prototype of 1927, the chassis designer had in the meantime been presented with the most intricate problems. Weight-distribution, suspension, steering, had all been made the subject of intense study — and subjected to it, as has been remarked, no sooner than was,due. Suspension particularly, which had remained basically unchanged from the days of the 1895 Panhard to those of the 1927 Delage, has undergone a revolution overnight. Independent wheel suspension, which appeared before its time on that 1906 Sizaire et Naudin with which this enquiry opened, seems destined, after a long eclipse, to become the rule rather than the exception.
With these facts in mind, I suppose, the experts have come to the conclusion that for the time being enough has been done for the chassis and that designers should now revert to the engine. With this conclusion I am in general agreement — although I must admit that I should like to have seen 4-wheel-drive established before the chassis was abandoned. But as to whether a capacity limit is the best means of’ focussing useful attention upon engines, I am very doubtful.
It will mean, of course, high crankshaft speeds, high compressions and high octane fuel. Now on fuel technicalities I am, if possible, more grossly ignorant than on most technical subjects — I am, for example, not even in touch with the Black Market in petrol coupons! But I understand that, at least in the case of the oilfield on which the world has got in future increasingly to rely for its fuel supplies, it is not possible to produce high octane petrol, without at the same time producing a relatively large residuum of lower octane value fuel. In other words it will never (though never, of course, is a long time) be economically possible to run the majority of internal combustion engines on the type of fuel which will be used by racing engines built to the new formula; and in consequence racing engines will tend to become more and more remote from ordinary engines, and the value of racing correspondingly small.
From which it would seem to me to follow that instead of limiting the capacity of engines, the authorities would be much better advised to limit the octane value of the fuel which could be used. Its reduction to the value of that, shall we say, of “Pool,” would, I suppose, dispose of the 200 h.p. per litre engine right away; but then the capacity limit rather than the octane limit could still usefully be used for sprint events, the Monaco Grand Prix and suchlike functions. so that high-speed engines could continue to show their paces. With “Pool” petrol to contend with, designers might be expected usefully to revert to alternatives to the poppet-valve, such as sleeves and rotary-valves. It would be interesting to see whether the Diesel engine would put in an appearance — bearing in mind the performance of the A.E.C.-engined car that G. E. T. Eyston used to run at Brooklands, and the subsequent technical development of engines working on this principle, I should be in no way surprised. Being, however, already well out of my technical depth, I will proceed no further but commend my suggestion to the appropriate authorities — confident that they will pay not the slightest attention to it. As to those more misguided persons who see fit to read these articles, they can at least pick holes in my arguments and contradict my facts, in the comfortable knowledge that I am used to it!
Note. — To those even more misguided persons who are still, unable to get accustomed to the effects of the French Revolution and who in consequence insist on calculating piston speed in feet per minute, I would just remark that it is customary to measure the stroke of European engines (with the exception of those made by Messrs. Rolls-Royce Ltd.) on a metric basis. (And long may it remain so; for over thirty years it was also customary in the case of tyres, and when they discussed the relative merits of 820 by 120 and 815 by 105, I knew what they were talking about; but after that an ill wind blew from over the Atlantic, and they started to talk about such things as “six hundred by sixteen”; and when I asked what “six hundred” meant, they said, “Why, six hundred hundredths of an inch, of course!” Which is what I call sense — but I fear that I digress.) So long, as I was saying, as strokes are measured in millimetres, I see little excuse for measuring piston speed in feet. But for the benefit of those who have been brought up to this heretical practice, I would say that, according to my “Willich’s Popular Tables,” 1887 edition., 1 metre is equal to 3.28089917 feet, and that I am sure that this piece of information will enable them to make the necessary conversion with facility.
For the Continental practice, followed throughout this article, of measuring engine speed in revolutions per minute and piston speed in metres or anything else per second, I can see no excuse whatever.