The trend of racing-car design

It is probably true to say that the past year has seen more pure design in motor-racing taking place than ever before, and if one counts sports-car racing in with Grand Prix racing, then this is certainly so. With Grand Prix racing being run under a new F.I.A. Formula, planned without recourse to available material, for the first time since 1938, the designers of racing cars have had a completely free hand. Since 1946 racing has been under Formulae that were laid down after looking to see what types of cars were available, instead of the more normal way of building cars to a Formula.

Admittedly there were many new designs during the years 1946-53, but mostly the competing cars were developments of the immediate pre-war racing. Now, however, we have started on a completely new era and with the Formula for Grand Prix cars that took effect from the beginning of 1954, designers and their factories have been able to start with clean sheets of paper and produce cars that bear little or no connection with previous models. Already, in the first year of the new Formula, we have seen two cars that have been built specifically for the existing rules, having no traces of parenthood of designs of past eras. Of these two, the Lancia is surely the best example of a completely new design, mainly for the simple reason that the Turin firm have never before built a Grand Prix car, so there was no background to draw knowledge from. The other car is the Mercedes-Benz, also a completely new design, but one that benefits in many ways from the years of racing experience that Daimler-Benz have had.

Of the other competitors in today’s Formula I racing, both Ferrari and Maserati utilise many parts of the designs of their racing cars of the past five years. Gordini is using virtually the same car as in the past, so that design in connection with the French cars is more a matter of detail work than basic racing-car design. As with the two firms at Modena, so Connaught and Vanwall have built new ears to the Formula, using knowledge and component designs developed with cars of the old Formula, but it is to the credit of the Vandervell team that they have an entirely new engine, though again this was originally laid down for the old Formula.

Today the field of Grand Prix racing is one of immense urgency, for the year’s racing has a very bare three months in which no events are held, so that the building of a new Grand Prix car calls for as much speed as is required when the cars are actually racing, and this naturally forces most designers, especially those with limited facilities, to compromise over many things and to use well tried components, either of their own design or those of specialist firms, rather than producing something new. The fact that the 1955 season opens with seven makes of Grand Prix car as highly probable entries, plus three more likely to appear before the season is over, shows a remarkably healthy state of affairs in which the multiplicity of design is such that has never been seen before. Of these makes there are already four that can produce the same average speed on any given circuit, without the skill of the driver being of paramount importance and it would be difficult to visualise four more different approaches to achieving the same end. These cars are Ferrari (four-cylinder), Maserati (six-cylinder), Mercedes-Benz (eight-cylinder) and Lancia (eight-cylinder vee). If you take almost any component part of any of these four cars you will find a remarkable lack of similarity in the design, while adding the other makes, Vanwall, Gordini and Connaught, the variants of any given theme make up a total that is stimulating in the extreme, and one that shows that originality of thought in the Grand Prix world is as high as it has ever been.

If we take these seven Grand Prix contenders and dissect them, comparing one designer’s ideas with the others, plus what little we know about the as yet unseen designs of B.R.M., Bugatti and Alfa Romeo, we shall get a very clear picture of the state of Grand Prix racing today. At the same time we shall be able to draw numerous conclusions and, though we may find that there are ten different ways of doing the same thing, we shall be able to trace certain trends along which Grand Prix racing-car designers are thinking. Taking the major components first, and of these the power unit, we find a great difference of opinion. The F.I.A. Formula allows engines of a maximum capacity of 2,500 c.c. if unsupercharged, and 750 c.c. if supercharged, and so far all of the seven current contenders have decided on the larger unsupercharged engine, naturally using the limit of capacity; both B.R.M. and Alfa-Romeo have been experimenting with the smaller supercharged type of unit, but so far without producing any conclusive results. The B.R.M. concern having developed their supercharged 1,500-c.c. engine, of the old Formula, to a very high pitch, it was natural for them to halve the design and try an eight-cylinder 750 c.c. Somewhat similarly, Alfa-Romeo have experimented with an eight-cylinder 750-c.c, and also a 12-cylinder one, it is rumoured, for they to learnt a great deal about small supercharged engines while racing under the old Formula, and they would naturally wish to make use of that knowledge. However, it seems unlikely that a 750 cc supercharged engine can produce 300 b.h.p. per litre, while the unsupercharged engines are already approaching a total power output in the region of 300 b.h.p., and as the difference in size and weight of the two types of Formula car would be almost negligible, the small supercharged engine would need to produce at least 270 b.h.p. from its seven hundred and fifty cubic centimetres. One thing we can almost be certain of, as a result of the new Formula, is that the supercharged engine will die out completely and this is a sad fact, for the supercharger is necessarily a fundamental part of motor engineering, but just as the normal gearbox is fast fading from passenger-car design, so the supercharger must be dropped from racing-car design. If something is discontinued, then naturally it has to he replaced by something better, and there is no doubt that the science of extracting horse-power from an unsupercharged engine has become so complex that the supercharger and all its problems are simple in comparison, and consequently the loss of the forced induction method of power-producing is being replaced by a technique with even greater possibilities. This is viewing the subject from pure basic engine research principles, but if we look at the possibilities of the two types of engine from the point of view of the future passenger car, then the lessons to be learnt from further development of the unsupereharged unit are many.

While most of the designers are agreed that 2,500 c.c.s of unsupercharged engine are the most likely to give the highest power output, with reliability, the way to utilise those 2,500 c.c.s shows virtually no agreement of thought. Mercedes-Benz and Lancia are the only firms who have built 2,500-c.c. engines from scratch and, while they agree on the use of eight cylinders, they are in direct opposition about the disposition of the cylinders. The German firm have all eight in line, while the Italians have theirs in two banks of four in vee formation, the one arrangement producing a long thin engine and the other a short fat one, as far as structural volume is concerned. Of the other cars, Ferrari retains the in-line four-cylinder arrangement he developed so successfully in the old 2-litre Formula, and likewise Maserati and Gordini use six-cylinder engines, having learnt much from similar layouts under their 2-litre cars. Connaught and Vanwall both use four-cylinder engines, the former mainly due to the Alta engine being the only reasonable one available and Geoffrey Taylor continues with a four-cylinder layout for the same reason as the Italians, namely the fund of knowledge gained with past engines of the same type. The Vanwall engine is an entirely new conception, from the brains of Messrs. Fox and Richter, and even though the engine was designed for the old 2-litre Formula, they are obviously thinking along the same lines as Lampredi when he designed the Ferrari engine. Whether the four-cylinder line is the right line is still not known, for it is rumoured, and quite strongly, that Lampredi has a two-cylinder 2,500-c.c. engine on the test bed. This is said to be in vertical twin form, similar in aspect to the almost universal 500-cc. motor-cycle engine of today. We see that on the first principle of engine design, that of the size of cylinder to use to produce the most power, together with the most usable torque, there is no agreement : some believe in the very small cylinder, others in the large cylinder, while the careful ones strike a happy mean. In addition to the engines in use at the present time, Colombo has designed an eight-cylinder for the Bugatti firm, while B.R.M. have a four-cylinder design.

In spite of many attempts with experimental engines to produce something to replace the well-tried poppet valve, this form of valve motion is still universal, no matter what arrangement of cylinders is used. Equally, the operation of the valves by separate camshafts for inlet and exhaust is also universal, twin o.h.c. in the ease of in-line engines and four o.h.c. on the Lancia V8.

Though the valves and the camshaft arrangements show agreement between the designers, the detail design in the actual operation of the valve, together with the driving mechanism for the camshafts, produces much originality of thought. That the valve is lifted off its seat by a cam is generally agreed upon, but how the valve is returned to its seat shows wide variation. Most outstanding in this matter is the Mercedes-Benz design of mechanically.-operated valves, where there are two cams for each valve, operating via short rockers, one to lift the valve and the other to return it. This is a mechanism known for many years, hut never before used so successfully as it is now by the Stuttgart firm; in this design detail they stand entirely alone. Of the others, the Vanwall engine uses two hairpin springs to each valve for returning it to its seat, the springs being so arranged that they remain fully exposed at all times, while Lancia use hairpin springs enclosed in the camshaft boxes. The rest of the engine designers use the traditional coil spring, in multiples of two or three to each valve. The use of light alloys for cylinder heads, blocks and crankcases is almost universal, Mercedes-Benz retaining the welded sheet steel construction for the cylinder block that they have believed in for so long. It is interesting to note that on their new sports/racing engine, which is of identical general pattern to the Grand Prix design, they have discontinued this welded form of construction and are using a cast alloy block. Ferrari stands alone in having a one-piece casting for his cylinder head and block, while Vanwall breaks new ground in the car world by clamping his cylinder block between the head and crankcase by long single-piece studs that, do not bear on the cylinder block at all.

In the matter of inducing fuel and air into the cylinders there are two schools of thought, one being the use Of a multiplicity of carburettors, and the other the use of fuel-injection, though in this there are two separate views. Taking first the carburettor, it is generally agreed that some arrangement that provides one carburettor to each cylinder is desirable and this can be effected by using a single instrument to each cylinder, as is done by Vanwall, or the more popular arrangement of the paired instrument as produced by Weber or Solex in which each carburettor has two chokes, with separate jets and throttles, but with a common float chamber. This arrangement gives the effect of two carburettors in a more compact space and, depending on the type of engine, two or more of these are used, Ferrari uses two double-choke instruments, Maserati uses three, as does Gordini, while Lancia uses four. The in-line engines use horizontal chokes, the carburettors being Italian Weber instruments, while Lancia uses downdraught Solex carburettors. Fuel-injection is employed by Mercedes-Benz and Connaught, the German firm developing its own system, in conjunction with Robert Bosch Ltd., while the English firm use a system developed by S.U. Ltd., though incorporating many Connaught modifications. The main difference between ths two systems is that the German system injects fuel direct into the cylinders and the English one directs fuel into the inlet tract. Daimler-Benz use an in-line eight-plunger pump to deliver the fuel to each of the injector nozzles situated fairly low down the cylinder wall, the nozzle being masked by the piston at the point of combustion. The S.C. pump, as used by Connaughts on their Alta engine, has a wobbleplate operating a ring of plungers, the fuel being fed to the nozzles mounted in the four inlet pipes. As originally supplied the four inlet pipes were fitted with butterfly throttles, these being coupled to is common spindle, but a Connaught modification was the fitting of a large,diameter collector pipe coupled to the four inlet pipes, with a single large-diameter butterfly throttle at the front of the system, an arrangement identical with that used by the German concern. On the English fuel-injection layout the pump is mounted on the rear of the engine, driven by the inlet camshaft, while the Bosch pump is mounted on the side of the Mercedes-Benz engine and in consequence it suffers from a certain amount of overheating, which causes the fuel to vapourise when the engine is hot but not running. To overcome this the driver is supplied with a hand pump which circulates fresh fuel round the injector pump, thus cooling time fuel gallery from which the pump has to draw when making a high-temperature restart. Although only two makes of Grand Prix cars are using fuel-injection satisfactorily at the moment, it can be expected that many more will follow this trend, for it has many points in its favour, though equally it has as many difficulties. Both Maserati and Ferrari have experimented with fuel-injection, but as yet have not used this system of carburation under actual racing conditions. With fuel-injection it is possible to obtain much greater accuracy of fuel/air ratio and in consequence higher power outputs can be realised. In addition a fuel consumption no greater than with normal carburettors can be achieved for a greater power output, and 1954 saw the Mercedes-Benz cars running through a full-length 300-mile Grand Prix race without the need for refuelling, while. some of their rivals using carburettors were getting very near the limit of their fuel capacity. It is worth mentioning here the so-called fuel-injection system as developed at Indianapolis by Hilborne, and used for some time by Connaught. This was a rather crude arrangement which supplied a constant stream of fuel into the air intake for each cylinder, the quantity being varied with engine speed but no attempt being made to time the feed of fuel with the piston movement. This arrangement was really only an improvisation to overcome the lack of sufficiently large-choke carburettors and was extremely wasteful on fuel. Alongside the Bosch or S.U. systems the Hilborne cannot be truthfully considered fuel-injection, though doubtless Connaughts learnt a lot of useful information from their experiments with the American system.

The question of carburation has two very definite trends. First, the provision of one choke-tube to each cylinder for high power output, and, secondly, the inevitable, but rather slow, abolition of the normal carburettor, it being replaced by some form of injection. One detail that has become universally adopted is the provision of two sparking. plugs per cylinder, this layout being used in time tiny cylinders of the Mercedes-Benz and Lancia engines, as. well as in the large space of the Ferrari engine. Ignition by magneto is almost universal, though Connaught are using coil ignition, but this is dictated by the lack of a suitable magneto rather than as a principle of design.

Exhaust systems still provide designers with much choice of thought, for there are few real conclusions yet proved. Gordini and Maserati, as exponents of six-cylinder engines, are in agreement over the use of two long tail-pipes: one from the front three cylinders and the other from the rear three. The: use of stub pipes has been abandoned completely and for four-cylinder engines there are many variations. Ferrari couples cylinders 1 and 4, and 2 and 3, with the two pipes joining a considerable way down the tail-pipe, which itself runs out beyond the tail of the car. On this layout a large diameter pipe has been used for a long time, but recently Lampredi has been trying pipes of smaller diameter. Vanwall uses four separate pipes joining in a bunch quite close to the engine, with a long thin tail-pipe. Connaught uses a Ferrari layout, but joins the two pipes close to the engine and has no tail-pipe, while the eight pipes of the Mercedes-Benz form two lots of four with short tailpipes. The two groups of four on the Lancia V8 are somewhat similar to that used by Vanwall, with very long large-diameter tail-Pipes.

Having dealt with the power unit we should now consider the gearbox and one thing that is becoming popular is to design the gearbox and rear-axle assembly as one unit. With the advent of i.r.s. or de Dion rear suspension, the gearbox somewhat naturally was built as part of the rear assembly, but a further move, as exemplified by Maserati, Ferrari and Lancia, is to design the complete assembly as one unit, rather than two parts bolted together. Both Maserati and Lancia have gone one step farther in mounting the gearbox part a the assembly to one side of the centre line, with the gear-shafts running across the car, Lancia going as far as to incorporate the clutch in this assembly. Ferrari, Vanwall and Connaught have the gearbox in front of the differential assembly, while Mercedes-Benz have it behind. In all cases there is complete agreement over the use of a train of gears to raise the propeller-shaft line up to the wheel centre-line height; even Gordini is in agreement on this point, having a step-up gear train on the front of the differential assembly, though in this case the gearbox is attached to the engine, due to the car having a rigid one-piece normally-sprung rear axle. As far as the number of ratios incorporated in the gearbox is concerned, the general trend is for five speeds, and the reasons are numerous: Engine revolutions are continually increasing, Mercedes-Benz using over 9,500 r.p.m., Maserati and Lancia 8,200, Ferrari 7,400, Gordini 7,000, Vanwall 6,500 and Connaught 6,200, and in consequence the bottom useful rev.-limit rises, so that the use of five speeds to keep the engine working within its best rev.-range is becoming essential. In addition the maximum speed of today’s Grand Prix cars is not far short of 170 m.p.h. and with a four-speed gearbox. Such as on the Ferrari of Maserati getting away from a standing start was a matter of extremely fine judgement, to find that crucial point between stalling the engine and spinning the wheels.

Mercedes-Benz designed their cars with five-speed gearboxes, so that when pulling a very high axle ratio, as at Reims, they had an enormous advantage over their rivals both at the start and getting away from slow corners. Gordini also built a five-speed gearbox for his cars, again with the object in view of making the initial start a great deal easier.

On production cars in this country the use of an overdrive to supply a fifth gear is becoming increasingly popular, but this must not be confused with the design of a five-speed gearbox. The overdrive merely supplements a rear-axle ratio that is too low and its use allows for lower engine revolutions at a given speed. The racing. five-speed gearbox is a very different thing and is an approach towards the ideal, which is a constant-speed engine and an infinitely variable gear train to transmit the power to the road wheels. Alone in this gearbox question stand Connaught, who stick to a preselector gearbox of proprietary manufacture, whereas all the other firms. build their own units.

The control for the gearbox shows no particular trend, the designer. paying no thought to whether a driver can operate a lever better with his right hand or his left hand. Mercedes-Benz, Lancia and Maserati use right-hand levers, Ferrari and Vanwall left-hand; Gordini central, and Connaught have their Selector-quadrant amounted on the steering column, albeit moved by the right hand.

Having discussed the major mechanical components we should now think about the frame into which to place them; here there are two very clear schools of thought, either to use a multiplicity of small-diameter tubes, or a minimum of large-diameter tubes. Mercedes-Benz, Lancia, Vanwall, Ferrari and Maserati all favour the use of a framework built, of small-diameter tubing, this frame forming a rigid box like structure, While Connaught and Gordini adhere to the old idea of a main frame made from two large-diameter tubes, lying parallel with one another. Both Mercedes-Benz and, Lancia have taken the “space-frame,” or multi-tube layout, to its absolute limit, using tubing of barely one inch diameter, and stressing every tube to do only the minimum work required, while Lancia have gone even farther by eliminating the tubes from the front part of their “box ” and replacing them by the engine, the cylinder heads having lugs east in to which the chassis frame is bolted. Ferrari, Vanwall and Maserati are a little more conservative and use tubing of nearer 1 1/2 inches diameter for their space-frames, using some of the inherent bending strength of the tubes to give the frame stiffness, instead of relying purely on tubes in tension or compression. While the multi-tube type of construction provides a simple way of producing an immensely strong basic frame, it can bring its difficulties, and among these are the problem of getting the various components into the space formed by the frame, while Mercedes-Benz were cramped for room when they discarded their streamlined bodywork, the “space-frame” design forbidding any redistribution of the various components. Vanwall found the problem of having a “space-frame” that was far too rigid, his suspension calling for slight flexibility in the frame, and this problem was stumbled on by Maserati with their first ” space-frame ” though it was later overcome. Bearing in mind that Gordini is limited in his design by the need to modify existing cars, it means that in reality Connaught are alone in not using some form of “space-frame” and designer Rodney Clarke remains unconvinced that the multitube type of construction offers more advantages than disadvantages, his main objection being the fact that a car must be designed as a whole with this type of frame, allowing no possibility of modification to major components.

Suspension systems show some very decided trends, though the details are still full of original thought. One trend that has now become universal is the use of independent front-wheel suspension by means of double wishbones, providing constant wheelbase but varying track. Even B.R.M., who have stuck to trailing-link suspension at the front for so long, have now decided to use double wishbones on their new car, while Alfa-Romeo, another advocate in the past of trailing-link suspension, have gone over to double wishbones on all their production cars and their experimental sports/ racing cars, so that it would seem reasonable to assume that their Grand Prix car will have this type of front suspension. As to the method of arranging the wishbones, or constructing them, there is still much divergence of opinion. These range from wishbones of very wide base, as on the Connaught, to very narrow base, as on the Ferrari 553, and from unequal-length wishbones to equal length, both Lancia and Gordini using the latter system.

On the question of the springing medium designers show great individuality, Ferrari changing from transverse leaf-springs, used by him since his first Grand Prix car, to coil springs, Maserati retaining the coil-springs as used on their 2-litre cars, Mercedes-Benz and Gordini using torsion-bars, the former running forward of the front axle line, and the latter running to the rear. B.R.M. will continue to use their interesting and effective air-strut, while Connaught use a coil-spring with damper combined. Vanwall and Lancia continue the use of a transverse leaf-spring, the Italian firm setting a new standard of spring-size with leaves barely one inch in width. At the rear the de Dion system continues to hold pride of place, being used by Ferrari, Maserati, Lancia, Vanwall, Connaught and B.R.M., while Gordini continues to use a one-piece non-independent rear-end. Mercedes-Benz stand alone in defying the Comte de Dion, for they use a swing-axle system, where the two half-axles pivot about a point well below the differential assembly and, in spite of technical misgivings and unorthodox wheel movements on corners, there is no denying the fact that Fangio was able to win four major Grands Prix with these cars. Although the German firm seem to be able to control their cars with this apparently bad type of rear suspension, there is no sign of anyone else following their example, all the other designers being content to scheme-up variations on the de Dion theme.

The provision of double radius arms from each wheel hub to the chassis frame, in order to provide a constant angle parallelogram movement of the wheels, is unanimously agreed upon, but side location of the wheels varies. Ferrari use a simple block and guide location, as do Maserati, the block being located on the centre of the de Dion tube, but Lancia use a location mounted on a downward projection of the de Dion tube, while Connaught use a link mechanism that gives the effect of a Panhard rod. As to the position of the de Dion tube, there are again variations, Lancia, Vanwall and B.R.M. having it behind the differential assembly, Ferrari and Maserati having it in front, and Connaught almost over the top.

For rear-springing mediums the most popular is a transverse leaf-spring, this being used by Ferrari, Maserati, Lancia and Vanwall; Gordini, Connaught and Mercedes-Benz all using longitudinal torsion bars.

Brakes show two distinct trends, drum-type versus disc-type, and a feature of this controversy is that those makes with drum brakes have designed and built them themselves, while the advocates of disc-brakes utilise proprietary articles. Vanwall have developed Goodyear disc brakes to a state of complete reliability, together with very effective braking, while Connaught are fitting Dunlop disc brakes that have proved themselves in sports-car racing; Gordini has made a few tries with French Messier disc brakes, but with no great success. B.R.M. are expected to have Dunlop disc brakes this year, having tried them on their own Maserati. The Maserati firm are also experimenting with disc brakes. Meanwhile, Ferrari, Lancia and Mercedes-Benz adhere to drum brakes of their own respective designs, in all cases great attention being paid to drum rigidity and to cooling. Ferrari uses normal drum finning, Maserati uses transverse radial spikes, with a deflector shield to direct air through these spikes, Lancia use a combination of the two systems, and Mercedes-Benz use ducted turbo finning. In practice the results from these four systems would appear to be very evenly matched, with perhaps just a very small advantage to the Ferrari brakes, though the Lancia is really still an unknown quantity, having only been raced twice so far. It goes without saying that operation of all brakes, whether disc or drum, is by hydraulic means. A trend that looked as though it was going to prosper was the fitting of inboard-mounted brakes, in the interests of reduced unsprung weight, but with the exception of MercedesBenz, who use this mounting on all four wheels, the principle has been rejected. The problems of cooling the rear brakes and transmitting the drive of the front wheels inboard, plus the added weight involved, has caused even Lancia to abandon the idea after experimenting on their sports cars with this layout. To date designers are remaining faithful to drum brakes in the majority, but the disc-type are quite likely to supersede the more orthodox method, though as yet a Grand Prix has not been won with disc brakes.

In spite of the fact that all cars can go through a 300-mile Grand Prix, even at average speeds of over 110 m.p.h., without the need to change tyres, such is the progress made by Dunlop, Pirelli, Continental and Englebert, there is still a strict adherence to the wire-type of wheel on a Rudge-Whitworth splined hub. Only Connaught have made the fitting of bolt-on alloy wheels a standard item, though B.R.M. have used such wheels with a Rudge hub, on their experimental Maserati. Cast alloy wheels have already superseded the wire-type at Indianapolis and it is quite likely that they will do the same in Grand Prix racing, while the absence of tyre trouble must surely lead to a return to bolt-on wheels, which can be made considerably lighter than the knock-off type. In the interests of unsprung weight wheel diameters have stabilised at the 16-inch mark, though Gordini has experimented with 15-inch rims. It is unlikely that any further reduction in diameter will be realised, for as power outputs increase tyre sections will have to be raised to transmit the power, and the limiting ratio of rubber mass to wheel mass has already been reached.

The bodywork for a Grand Prix car is by no means a cut-and-dried subject and both Mercedes-Benz and Connaught have produced all-enveloping fully-streamlined bodies, and while the German concern have proved the advantage on some circuits, and big disadvantages on others, the English car has yet to compete in a race with this type of body. One of the disadvantages is said to be the reduced visibility, especially on the Mercedes-Benz, where the driver sits far back and in a reclining position. Connaught sits the driver well forward and rather high, so that a good view of the road is obtained. By arranging the bulges over the front wheels to be directly above the hubs it should be possible for a driver to sight his car on a bend as efficiently as the driver who can see his front wheels. On the Mercedes-Benz the trouble would appear to be due to the nose of the car projecting a long way forward and remaining the full width of the car, so that when the driver has sighted his front wheel on a corner, by using the indicating bulge, he must also make an allowance for the extra forward projection, especially when sighting the car in a four-wheel-drift.

If a car is viewed in plan view on a 100-m.p.h bend and the driver is sufficiently skilled to have the car at a high attitude angle, with the inside front wheel a few inches from the edge of the corner, then the inside corner of a rectangle containing the car will be well over the verge, even though the wheels remain on the track. This explains fully the trouble Mercedes-Benz experienced at Silverstone when the front of the car kept striking marker bins placed just inside of the white line representing the line of the corner. It is unlikely that the fully streamlined bodywork will become popular for the general run of Grand Prix ears, for it brings with it far too many problems which outweigh the extra speed gained. Among the problems are the increased weight, the problem of providing sufficient air-flow to cool the brakes, without spoiling the drag, the inaccessibility of the mechanical parts should a pit-stop be occasioned, to say nothing of the task of finding mechanics capable of working on the cars without causing damage to large areas of thin panelling. Connaught have overcome some of these difficulties by making the whole of the streamlined body above the wheel centre line lift off in one piece. This is a practical proposition for servicing but quite impossible for a pit-stop. Among the more orthodox single-seater bodywork there is a good tendency to provide a clean exterior and improve the air-flow, Maserati in particular producing a very smooth contour. Both Ferrari and Vanwall have cars with straightforward body panelling, though the 553 Ferrari introduces a new line with its pannier fuel tanks demanding very bulbous body sides. Gordini has a neat simple bodywork, and high cockpit sides feature on all Grand Prix cars these days, providing that the body is very wide at the cockpit to allow the driver plenty of elbow room. The headrest on the tail is still popular, being used by Ferrari, Mercedes-Benz, Connaught and Lancia, but none of them are high enough to provide a clean line from behind the driver’s helmet, the average driver sitting well clear of the headrest. Such shapes are a convenient way of covering up the fuel filler or providing extra tankage. The Connaught is alone in having a large tail fin incorporated in the headrest and this is a trend which is likely to increase with modern handling and bodywork with good air-flow. With Grand Prix cars cornering at anything up to 150 m.p.h. in controlled drifts necessitating quite large attitude angles, the effect of air pressure on the side of the car will become a serious problem and the use of tail fins to adjust the centre of pressure and control the cornering characteristics is a certainty. Already much ground work has been done on this subject by Jaguar and Bristol with aerodynamic sports cars.

Fuel tanks and their positioning occasion much thought, for 45 gallons of fuel represents a large proportion of the starting-line weight and can affect the handling characteristics of a car enormously.