Design certainly isn’t stagnant, but, leaving racing cars to D. S. J.. nothing very revolutionary was to be seen at the Earls Court and complementary Motor Shows. Nineteen-seventy will probably go down as a year in which design teams showed an uncertainty as to which way they should go, and in which automobile engineering concepts became muddled and confused.
For instance, not long ago the bowl-in-piston combustion chamber, borrowed from diesel practice and adopted notably by Rover for their then-new o.h.c. engine, was hailed as a worthwhile advance on cylinder heads possessing formed combustion spaces. Vauxhall preferred not to follow this trend, saying that exhaust pollution could be better controlled with flat piston crowns, but Ford went for b-i-p in a big way. For 1971, however, the exciting new o.h.c. Ford engine family, evolved in Germany for the American sub-compact Pinto and adopted for the more lively versions of the new Cortina, eschews b-i-p, although Dagenham retains this form of combustion space for its push-rod engines, not, one imagines, simply as a tribute to piston manufacturers’ advanced casting techniques. . . . Indeed, at the time of the World Cup Rally Ford were said to have used b-i-p heads because they were considered to cope better with the different ignition settings, demanded by the varying octane pctrols which would have to be used along the route. Surely Ford do not visualise their new o.h.c. power units being confined to “rich” areas of Europe where they will always be fed on good-quality fuel? If this rally stipulation is taken seriously, those who operate in the far corners of the Globe had better specify the push-rod b-i-p new Cortinas.
Another example of changed opinion, if not muddled thinking, is seen in the abandonment by British Ford of the MacPherson strut suspension unit to achieve a simple i.f.s. system (which Dagenham was once so anxious to promote) at the very time when the enormously successful Volkswagen concern has gone over to it, in place of the former race-bred Porsche trailing-link i.f.s.., for the uncrushable Beetle (it also confronts critics with an oversteer complex with trailing-arm i.r.s.). Then again, in the matter of styling we have Ford going for coke-bottle (why coke?) waist lines on the 1971 Cortinas just when the Vauxhall branch of GM have discarded this aspect of body shaping. And, with VW completely turning round its long-established policy of mounting an air-cooled engine in the stern of all its cars, on the new K70 water-cooled, front-engined, front-wheel-drive car, the condition of confusing change quite definitely exists. . . .
For Ford’s new Cortinas I feel considerable enthusiasm, because for many years I have held Cortina GTs in high esteem, and the fact that they have at last abandoned leaf-spring rear suspension gives me hope that riding in the back of one may now give the impression of being in an automobile running on round, not square, wheels!
It is said that the use of quieter Salisbury back axles, the construction of which suggests that they could be somewhat heavier than the axles they replace, enabled Ford to use coil-spring four-link rear suspension, which would otherwise have transmitted too much noise into the body shell. Be that as it may, we have the curious situation, at all events for the moment, of the more costly and prestigious Capris supporting their rumps on leaf-springs, which Cortinas now scorn. . . .
Moreover, while MacPherson strut i.f.s. has been abandoned for the brilliant new Cortina family, it is retained on the Ford Escorts and the sporting Capris, and is used by Fiat for the Type 128 which was avidly proclaimed by some as “The Car of the Year”. However, we must be patient. The new Cortinas have rack-and-pinion steering already adopted for Escorts and Capris, so in time we may see the latter Fords with unequal-length wishbone i.f.s. and coil rear springing. Ford claim their new i.f.s., although of conventional, unequal-length wishbone pattern, fits in better with their required NVH (noise, vibration, harshness) suppression than the MacPherson struts, although originally these struts were said to bring loading onto the bulkhead for this very purpose, and that the reduced wheel-offset lessens a shimmy problem. The honest reason for the adoption of wishbone suspension is probably better control of quality and supply, with Ford-manufactured parts. The new design gives, a periodicity of 66 c.p.m. on the 1600 GT cars, compared with 90 c.p.m. on the Mk.II equivalent, and the new coil-spring rear suspension has a 1.6 lower c.p.m., a ride rate increased by 36 lb./in. and a 5.7-in. increase in roll centre height, depending, of course, on tyre size. This study of Ford’s extensive suspension modifications reminds me that Rover use a complex linkage system at the front of their 2000/3500 cars expressly to transfer load and noise to the bulkhead, where they can be properly dealt with; I had hoped that these cars would by now have adopted a simpler layout, to lessen tracking complications while endowing them with even better road-holding, on a par with the outstanding “stiction” of the still-born Rover mid-engined coupe, but apparently Peter Wilks has had other things to attend to.
Independent rear suspension has not been taken up as quickly as the experts expected. Production costs allied to difficulties of noise suppression are chiefly to blame, especially where mass-production makes are concerned. But that which AC, Austin on the 3-litre, BMW, Bond, Datsun for their biggest car, Ferrari, Fiat on the luxury 130 and Dino, Jaguar, Lamborghini, Lotus, Maserati, Mazda, Mercedes-Benz, NSU on the advanced Ro80, Peugeot for their 504, Porsche, Rolls-Royce, Toyota, Triumph, TVR, Volkswagen, and even Ford for their biggest models, a list which includes some cars of impeccable handling characteristics, deem desirable in spite of the complexity of rear-wheel-drive, will one day become popular. Eventually we shall see rigid axles join side-valve engines, leaf-springing and beam front axles (with apologies to the Range Rover!) in museums. Acceptable standards of comfort as well as better wheel-grip must depend eventually on i.r.s., and in this context it is worth noting that the de Dion rear-end, once deemed so essential in racing when Mercedes-Benz “discovered” it, comes and goes, but in 1971 will have its adherents in the V8 Aston Martin DBS, the Monteverdi, and on Rovers.
Reverting to power-unit design, there has been a trend, slow to develop but growing, towards multiplication of cylinders, by which I mean the V8 engine. Commonplace in America—where, let us never forget, Ford led the way in big-production V8 engines with their classic pre-war V8 30, of economic but rigid construction, its then unusual cast-iron crankshaft inherited by modern Ford engines—the trend is increasing in Britain. Rolls-Royce went over to the eight in self-defence, Rootes used such an engine in the Sunbeam Tiger until Chrysler refused to buy the Ford unit they had shoe-horned into it. Peter Wilks, Rover’s talented Chief Engineer, took up what Buick and Oldsmobile had discarded, to give his company an excellent lightweight V8. British Leyland worked on a rather unusual new four-cylinder o.h.c. engine which they cleverly sold to Saab and then developed a 3-litre V8 for Stag. Triumph have thus beaten Jaguar in the multi-cylinder race, leaving us wondering whether the forthcoming Jaguar/Daimler vee-engine, rumoured to be ready for release during the first half of 1971, will use a cylinder head akin to that of Stag—which may be excellent technically but will be a blow to history, for Jaguar (and Alfa Romeo) are synonymous with twincam engines. With Alfa Romeo going to a 2.6-litre V8 for the Montreal, Aston Martin having finally evolved a satisfactory, if vintage-like, production version of their 5.3-litre V8, Maserati using nothing but vee-eights, Mercedes-Benz having a great 6.3-litre V8 in their R-R-prodding 600 and a 3-1/2-itre V8 for their very interesting 300SEL model, and Ferrari and Lamborghini supporting the V12 school, multi-cylinderism is in quite a healthy state. There is likewise growing affection for six cylinders arranged in the compact vee-formation. out of which Ford has done remarkably well, to be followed by Fiat and Citroen. The Ferrari and the Fiat Dinos also have V6 engines, the Ferraris mounted transversely, in keeping with the significant developing trend towards mid-engined, high-performance, high-cornering-power motor cars, of which the Lotus Europa is an excellent British example.
The two-stroke engine is about to join the Dodo-status side-valve four-cycle power unit so far as private cars are concerned. Forty years back, in an era which now makes VSCC eyes sparkle, o.h.v. had already ousted the s.v. layout on British marketed cars by 47.6% against 39.1% (sleeve-valves and two-strokes were still in the land, to make up the balance), and today o.h.v. engines entirely dominate the scene, the Wankel apart. At one time an overhead camshaft was looked upon as a desirable but extravagant component. Praise was bestowed on those makers, like Peugeot and Riley, who obtained the basic advantages of twin overhead-camshafts without their complexity, using base-chamber camshafts but with ingenious push-rod-and-rocker arrangements extending from them. All this now belongs to the past, thanks to the cogged rubber-belt drive for upstairs camshafts, as proved by Pontiac. With a sweeping under the drawing-office carpet of chains, trains of gears, vertical shafts and bevels, even eccentrics or cranks-cum-connecting rods, there is little reason why every car does not have an o.h. camshaft. The silent, efficient, inexpensive cogged-belt drive is to the o.h.c. head what electric ignition was to Herr Otto. British Leyland do not apparently care for it, but Ford, Fiat, Citroen, Vauxhall, Opel, etc., eagerly adopted it.
For this reason it is easier to record those who still adhere to pushrod prodding of poppets than to catalogue the o.h.c. advocates— they include BLMH, who, however, have o.h.c. on the Austin Maxi and Stag, Citroen on their older cars, DAF, Datsun for their smallest model, Fiat on their babies and one version of the Type 124, although the 128 has an o.h.c., Ford for their bread-and-dripping jobs, Chrysler/ Hillman (except on the light-alloy Imp family of engines), Lancia on the Flavias, the little Mazda, some OpeIs, Peugeot 404 and 504 (with every excuse, however, for they have the aforesaid clever push-rod gear), Renault, Rolls-Royce, Rover (except on the 2000s), Simca, Skoda, the smallest Toyota, Vauxhall on its older cars, Volga, VW for its horizontally-opposed power packs, Volvo, and all American engines sold here, except for those in the new sub-compacts.
But for how much longer? There would appear to be no dramatic drawbacks to o.h. camshaft valve gear using cogged-belt drives, compared to push-rod operation of o.h. valves, apart from the requirement of rather more oil for the camshaft bearings than is required for rocker shafts and push-rod ball-ends, except for complications in tappet adjustment, which ingenious engineers such as Fiat and Vauxhall have overcome. However, as engineering is such a fascinating compromise, I shall not be surprised if the makers of chains and sprockets do not take me up on this matter . . . As I mentioned last month, I have had the interesting experience of being at the wheel of a Ford Escort RS when both its camshafts and its ignition distributor ceased to rotate, so that my Motor Show commuting had to be done in that excellent small car, the Fiat 128. The cause of the demise of the BDA was a seized front bearing on the exhaust camshaft, which stripped the cogs from the driving-belt and bent two valves. The sump was full of Duckham’s at the time and the revs were minimal when the engine locked up, so this perhaps underlines the lubrication complexity of twin o.h. camshafts.
Incidentally, it may well have been the disuse of full-scale bevel-gear and gear-train drives for o.h.c. engines which induced Castrol to discontinue their XXL and GP lubricating oils. This will be bad news to owners of vintage Bentleys and 6C Alfa Romeos, who will be obliged to search for Agricastrol 50 (or Shell’s Talpa 50), as these engines prefer a monograde SAE 50 oil.
The classic twin-cam racing-type cylinder head compared to a single o.h.c., adds to production costs and engine weight. But I am very glad to know that this still figures on the better production power units made by Aston Martin, Alfa Romeo, Citroen, Fiat, Ford with the classic 16-valve configuration, on the four-cylinder Escort RS, Honda, Jaguar, Lancia, Lotus and Maserati.?
Engine design has remained basically the same for over a century except for the advent of a completely unconventional i.e. prime-mover in the form of the NSU-pioneered Wankel, adopted by Mazda. The Ro80 has not proved altogether reliable in the hands of those NSU owners who have ventured to dispense with pistons, so Dip.l-Ing. Uhlenhaut of Daimler-Benz was apparently right in making haste slowly with this rotary engine for use in Mercedes-Benz cars. Rolls-Royce, however, are experimenting with a diesel-Wankel which may cheer up their unhappy shareholders (or may not).
The way in which front-wheel-drive has raced ahead for the smaller cars and even some quite large ones, is what the pundits of a decade ago anticipated, although, here again, some makers seem unable to decide which is better, front- or rear-drive, or perhaps wish to make the best of both worlds—Triumph, for instance, and Renault and VW, nor have we forgotten Simca’s and Fiat’s dilemma, if such it is, of having front-engine f.w.d., front-engine r.w.d. and rear-engine r.w.d. cars all in the same showroom, as it were! Different applications of transverse engines and front-wheel-drive are illustrated on page 1238 from which Fiat and Simca seem to have best overcome the particular technical conundrums involved. Honda use this layout, with the simplification of air-cooling. The next stage must be to have makers other than Rover (on the Ranger) following the sure path of Jensen with four-wheel-drive.
In the matter of carburation, and exhaust manifolding, the trend towards vee-engines may bring fresh problems or reintroduce ancient ones, and in this respect, it is interesting that Citroen’s latest, very advanced small car has joined VW and Porsche in the pugilistic field of the boxer-motor. On a personal note, I always feel that a Weber carburetter does most engines a power of good, so I am interested to see that, outside Italy where these excellent carburetters are made, they have been adopted by Citroen (not unexpectedly, with their Maserati tie-up), Ford, Gilbern, Ginetta, Lotus, Marcos, Morgan, Porsche, Reliant, Simca, TVR and Uren for at least some of their models. BLMH are wedded to SU, and supply these long-established carburetters to Aston Martin and Rolls-Royce. Fuel injection is coming into its own with Alfa Romeo using their own conception for the V8 Montreal engine, Aston Martin having Bosch on their V8, Marcos using Lucas equipment on their new Mantis, Mercedes-Benz, Porsche and VW naturally having Bosch injection, the Triumph TR6 supporting the Lucas method, Volvo having Bosch, Peugeot and Lancia preferring Kugel-Fischer equipment. Compression ratios rise higher, AC, Auto-Union Audi, Iso, Lamborghini, the Lancia Fulvia HF, Lotus Europa, Monteverdi, Morgan Plus-8, Plymouth Barracuda, Rambler Ambassador, the Rover V8s and the Volvo 1800 have a c.r. exceeding 10 to 1, while 10 to 1 isn’t uncommon.
The trend of automobile design swings fascinatingly this way and that. At the close of what we enlightened folk now call the vintage era, the British shopping for automobiles had the choice of twice as many six-cylinder in-line engines as fours, and 18.3% of the cars available during 1930 had eight cylinders, both in-line and vee pattern. So there is nothing very new about multi-cylinders, especially as there were 12- and even 16-cylinder power units in production by 1930. It is detail design which has raced ahead, for although Peugeot introduced twin-cam multi-valve engines for racing in 1912 and Leyland had a silent o.h.c. drive by 1920, they would have regarded as completely lunatic the driving of camshafts, no matter where they were situated, by a length of flat belting.—W. B.
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