ON ACHIEVING HIGH PERFORMANCE
ON ACHIEVING HIGH PERFORMANCE
By W. BODDY A very experienced automobile engineer told me the other day that in his opinion the buying public will very soon be demanding maximum speeds of 100 m.p.h. from production sports models. He knows the new German Autobahn, where cruising speeds and maximum speeds converge to the detriment of any engine the reliability factor of which weakens in the higher speed ranges, and he is familiar with conditions in America where he seriously believes that a 100 m.p.h. maximum will soon be the primary “selling-appeal.” And he says that over here, in spite of our hopelessly out-ofdate roads, the more wealthy sportsmen, who run big-engined fast cars, will soon be seeking assurance that if occasion
permits and the mood moves them, a three-figure speed is wa.ting to be unleashed.
It is not proposed to dwell upon the possible accuracy of what is certainly an interesting prophecy, but there is no denying that present traffic conditions in this country, where we are continually checked in our journeyings by traffic-lamps, etc., do make high performance in all its aspects Invaluable to all those who motor seriously for business or for pleasure. Now it may strike you as curious that the very items of performance that were once the playthings of enthusiasts should, in A.D. 1937, play a vital part in the speed and safety of modern motoring. Yet it is a fact that every designer who is worth his salt, attempts to instil into his mechanical child, at least, a reasonable degree of speed, liveliness, controllability and braking power, and, generally speaking, the fairer the distribution of these desirable performance factors, the nearer to commercial success is the vehicle in which they are embodied. This state of affairs cannot fail to be extremely pleasing to sports-car enthusiasts, because all the sports-cars that have been evolved in the past have contributed something to our existing knowledge of how to achieve high performance, no matter how many of these cars have long since faded out, perhaps bringing despair and financial ruin on the shoulders of their optimistic sponsors. Likewise, all the
efforts of the pioneers in preparing and racing fast motors over the race courses of Europe, some of whom achieved fame and fortune, many more of whom merely worked hard and risked their lives for no concrete return, have not been in vain.
One day I propose to collect all the bound volumes of “The Autocar ” and MOTOR SPORT and as many back issues of Pletcher’s ” Motor Car Index ” as I can lay hands on, and then retire to anywhere where the sun always shines and the wine and women are as they should be, there to write on the Evolution of the Sports-Car. Then perhaps I shall have a clear idea of what and when was the first sports automobile, and of the comparative efficiencies of the better examples through the ages. All I know now is that there were really no ” sports-cars ” before the War. There were some extremely potent fast motors. then in existence and in production. evolved to suit the requirements of those sportsmen who were returning to the idea that must have possessed nearly everyone right at the beginning of things, namely, that motoring embraced more than utility transport from A to B. Witness, for example, the Alphonso Hispano, the Alpine Rolls, the Prince Henry .Austro-Daimler, the Ninety Mercedes-Benz, the Prince Henry Vauxhall, the Shelsley Crossley, the big La Buires and Talbots, etc. Certainly these cars were fast, and I will hazard a guess that, in spite of their avoirdupois, they picked up rather better than most of their brethren, but they were outwardly just touring cars, and certainly did not figure as anything else in their makers’ literature. But they had big engines from which more power than usual wa.s developed by enlarged bores or the applications of such tuning tricks as had
been learnt in a decade of fierce racing, and the germ was released. Even the 30/98 Vauxhall was not really a special sports job, for when Laurence Pomeroy (then of Vauxhall s, though he afterwards went to Daimler s and is now helping to maintain the reputation of the worlds most popularsmall aero-motors, at De RaviBands) evolved the original 30/98 in 1913 for Mr. Higginson, he merely
did some drastic things to a 25 h.p. Vauxhall touring engine and thrust the result into another Vauxhall chassis for
which the big engine was never intended.
The power/weight ratio was abnormal and then, as now, that was the key to remarkable performance. But the 30/98 only became a sports-car, as such, in 1923, when valves in the head endowed it with 22 extra horses, in spite of a stroke docked of ten good millimetres.
After the War, however, the specialised sports-car duly made its bow ; perhaps because the war-time aeroplane was a plaything that made certain engineers’ blood flow quickly, stimulating their peace-time imaginations. At all events. W. 0. Bentley, Burgess Of Humbers and some draughtsmen got together and gave us the 3-litre Bentley, sixteen valves, fixed head, shaft-driven o.h. camshaft, dual magnetos, dry-sump and all. The very first Bentley engine is still in existence and aroused much interest at the recent Bentley Drivers’ Club dinner. Other advanced methods of wooing highpheCrrformance followed. Seabrook had a remarkable aluminium o.h. camshaft engine in 1921. Bugatti startled small car folk by reason of an o.h.c. engine in which volumetric efficiency and mechanical losses were carefully studied. Later Salmson came to the twin o.h.c. idea. Lancia weaned the Lambda, ParryThomas the renowned Leyland Eight. Sunbeam applied their Grand Prix racing lessons to the production of the sports 3-litre in 1925. Lagonda had the 2-litre with ” underhead ” double camshafts, blown in later years. Straker-Squire built a camshaft ” six ” with separate cylinders, Vulcan tried twin camshaft construction, Lea-Francis likewise, as eventually did the Beverley-Barnes concern (which so faithfully served the old Bentley Company) after having tired of making an imitation Rolls-Royce. The Triumph people returned to a very ad vanced engine quite recently. Superchargers were applied to all manner of power-units, including the beautiful little Amilcar Six. So no one can deny that much money and thought, and some sound engineering, was devoted to development of the more advanced ” racing ” class of
high-performance car. But, parallel with this, ran another awl very important development, namely, the introduction and perfection of what is best referred to as the semi-sports car. M.G., Isotta, Hillman, Hispano, Sunbeam, Riley, Fiat, Alvis, 0.M., Excelsior, Royer, H.E., Ansaldo, Alfa-Romeo, Triumph. HadfieldBean ; scores of others, listed sporting versions of their utility models, or made semi-sports chassis. It was a question of reducing the wheelbase, lightening things a bit, tacking on another carburetter, perhaps altering gear-ratios and replacing cast-iron pistons with alloy. The net result was greater liveliness and 10 or 13 m.p.h. more pace, without untold upheaval of the manufacturing plant and, with hick, little additional worry for
the service department. Engineers were pocketing their dreams and getting out practical high-performance cars that would sell and show a profit.
Now I am going to ask you to bridge a gap and come to the present state of things, because, although we do not publish a serial story, MOTOR SPORT is not elastic, and I cannot here mention every line of development. What do we find. ? The sports-car posing as a touring car finds no place, because substantial construction does not permit of modern performance standards with power-units of ” utility ” design. I suppose that prewar tradition filially died when the sidevalve 20/70 Crossley and 45 h.p. Renault sports job ceased production. But a modern counterpart is found in the highperformance American, with Side or push-rod o.h. valve, multi-cylinder engine. True, such engines are subjected to extensive research and employ quite highcompression-ratios and sO on, but virtually they are Simple units, suited to quantity production. They hold their tune splendidly, are very lively and, mounted in light chassis, they are productive of a performance that shames
many of our truly expensive sports motorcars. The average big American has a power/weight ratio around .92 lb. per c.c., and that spells performance of the kind that is so very desirable under this Belisha regime. I have a great respect for these transatlantic automobiles, which are well suited to those seekers after high performance who do not have to devote too much attention to running expenses and who do not expect a car to serve in 1946 as it serves in 1936. Take just one example :—the Ford V8, now an allBritish production. With a big closed five-seater body it does 80 m.p.h. on top, it can accelerate from rest to 50 m.p.h. in about 11 seconds, and it does over 20 miles to a gallon.
At the price, what a truly remarkable car ! The only thing that Makes me shudder when I contemplate the extent of the American Invasion is the thought that so much performance is there to be turned on by so many people who have not the qualities that make a safe sportscar driver. Moreover, these cars are built for comfort, and are consequently suspended on very supple springs and given very low-geared steering. A friend of mine who loves the real motorcar Once suggested to me in all seriousness that a special speed-limit should be imposed cm cars of this kind. Actually, they are quite safe, of course, if they are sensibly driven, but they do not handle quite as well as our better high performance cars. I don’t think there is any special mystery about this, whatever teelmicians May make of it. If you have ever built Meccano Models of cars or trucks you will probably recollect how badly they ran if the axles were at all out of parallel. Now normal leafspringing systems put the axles out of parallel every time a wheel rises over a bump or dives into a pot-hole, and with flabby tyres and the considerable weight involved, it is not surprising to me that rough surfaces and tram-lines often impart a feeling of insecurity to our modern touring cars. That, I think, is _quite a good argument in favour of independent suspension, quite apart from safer riding and decreased chassis movements. It is also a sound reason why you should see that spring pivots and shackles are in first-rate trim, particularly if you run. an elderly Motor. The Railton, BroughSuperior, Lammas-Graham and Jensen, as naturalised Americans, have chassis more suited to fast driving, of course. Coming to sports models in general, we see the outcome of those semi-specialised jobs, or gingered-up tourers, of a past decade. For the trend is to employ quite straight-forward engines, usually with vertical o.h, valves actuated by push-rods and rockers, normally disposed components, and ordinary constructional method. The netessary responsiveness and output of adequate horses is achieved by careful attention to details of design. And because these emjnes possess horses with hairier legs, as S. E. Cummings would put it, than purely utility power-units, it is possible JO offer higher performance while using more rigid chassis frames. More rigid chassis members spell vastly improved road-holding, and, although we Once used 1;0 maintain that only racebred motors really controlled properly
at speed, I think you will concede that all modern cars that are justified in going down in their maker’s literature as” sports models,” leave nothing to be desired in this respect. I will not attempt a list of all the cars that follow this trend, because I should probably forget some of the best, but engines like those of the modern M.G.s, and Frazer-Nash-B.M.W.s and Bentleys and Lagonda, Alvis, Talbot, Riley, Rolls-Royce, and lots and lots of others are the type I have in mind. A very handsome performance with a hili degree of economy and complete reliability is :possible with this lhie of attack. What of the ” pur sang ” ? Certainly it is by no means defunct. Bugatti and Alfa still make racing-type sports-cars and Merc&Rs-Benz applies a very fine blower system (blower is correct in this instance) to a more normal engine, thereby trapp:ng the high spots of both
types. W. 0. Bentley is helpingthe V12 Lagonda to cut its teeth and Georges Roesch displays real artistry in the design of the eight-in-line Sunbeam. A.C., Alta, Frazer-Nash, Rapier, BritishSalmson and others woo high performance in the most effective method of all, justifiable when first cost is mit of extreme importance and when the designer is a man of true ability and long experience. Those who favour this method of inbuilding performance can take heart from the fact that out of all the cars tested in a twelvemonth by ” The Autocar,” only the modern 5-litre blown Merceths-Benz and a second hand Type 55 blown tw.ncam 2.3-l’tre Bugatti and a secondhand 8-litre twenty-four valve oh.c. Bentley achieved the magic 100 m.p.h. Advanced engines of this sort develop SQ much power tnat chassis can be planned to give the highest possible controllability, for weight hasn’t to be lopped off here and eliminated there or space conserved to further reduee avoirdupois. And a man who can design machinery of this kind should be able to make a steerable chassis to accommodate it. It used to be said that such engines were unsuited to road conditions, being
noisy, oiling their plugs frequently, and being very costly to service. But when Ettore Bugatti offered the sporting public his first twin-camshaft sports model six years ago, he proved that extremely high output is possible without invoking these shortcomings, and if maintenance is a big item, there is the consolation that high gear-ratios can. be pulled and the mileage between. top-overhaul can be considerable: And if anyone doubts the silence of .over block camshaft machinery, he has not been out in the Type 49 and subsequent Bugatti models. Small capacity engines usually depend on high rates of revolution for the output of horses in a quantity sufficient to produce vivid performance, even given a light chassis, and in this respect advanced design has points in its favour. Admittedly this method of trapping Sporting performance does not show up so wellagainst that which utilises a carefully designed modern engine of conservative layout in a frame of moderate weight. But had the development of the
pur sang” been carried along with equal fervour the position. would be very different, as witness the capabilities of that ex-Birkin blower Bentley or the possibilities Of a supercharged 8-litre Bentley or a 575 Bugatti with the G.P. motor, for instance.
But with Hore-Belisha on his throne, and remembering the limited number of persons who could purchase and drive such motors, this development appears illogical.
So, in looking to the future, when the buying public will seek that 100 m.p.h. maximum and even better acceleration than it now enjoys, I visualise a mediumcapacity push-rod sort of motor-car, as likely as not endowed with those hairy horses by the correct application of .forced induction. It may even be that Laurence Pomeroy, Junr., with the variable delivery Velox supercharger, is due to start a new era in sports-car motoring, just as his famous father did all those years ago before the War.
Continued on. the 3rd column, next page. ON –1( 1111:71/ING PERFORM N( E from preceding page
Certainly I have heard of some interesting experiments with one of our most outstanding high-periormanee marques, in which a silent centrifugal blower is being employed to increase the upper-end performance of an engine sensitive to camshapes, which already gives an excellent output at lower speeds with its existing highly satisfactory camshaft. A straw in the wind, perhaps. In the meantime there are three distinct ways of achieving high performance, and it is up to you which one you choose to buy.