Jaguar’s new V12
At a time when new British cars lack glamour or mechanical ingenuity, the advent of the long-awaited V12 Jaguar engine in a revised Series-3 version of the famous E-type high-performance car is a significant event. To celebrate it, Motor Sport publishes in this issue D.S.J.’s opinion of the new 5.3-litre twelve-cylinder E-type, as he has a profound knowledge of these cars gleaned from big mileages with two six-cylinder twin-cam E-types and was allowed to drive two versions of the new model on the road six weeks ago, and a full description of the new engine and how it is made by the Editor, who was permitted to examine it and discuss it with its designers at Coventry. There is a colour picture of it on the front cover and further colour illustrations on pages 347 to 350.
The production V12 engine is far from being a fresh concept, but Jaguar has the distinction of being the first British manufacturer to appear with one since the end of WW2. Indeed, the use of a dozen pots dates back to 1915, when Packard was selling a successful “Twin-Six”. Haynes and National followed suit and in Europe after the war Fiat introduced a neat 7-litre V12, Voisin a sleeve-valve of this layout (and was the only maker sufficiently eccentric to build an engine with 12 pots in-line), and some years later Daimler countered competition from the Rolls-Royce six-cylinder New Phantom with a series of complicated “Double-Six” models, made in both Knight and poppet-valve form, of from 3.7 to 7-litres, which conveyed our Royal Family around in an aura of dignity and blue smoke.
By the end of the vintage era the V12 was available in America from Auburn, Cadillac, Lincoln, Packard and Pierce-Arrow and represented the epitome of luxury, until the arrival of sixteen-cylinder models from Cadillac and Marmon, abetted by Bucciali in France. The V12 trend extended to Horch and Maybach in Germany, the latter’s Zeppelin model claiming airship-engine associations, and even to Czechoslovakia, where by 1930 Tatra had a 6-litre side-valve twelve with all the manifolding within the vee. Further kudos was given to the V12 when Birkigt concluded his splendid run of Hispano-Suizas with cars of this type, the largest of 11.3-litres, and when Rolls-Royce came round it considerably later, with the magnificent 7.3-litre Phantom Ill, both owing something, it is alleged, to aero-engine thinking, although they employed push-rods to prod their valves. Delahaye had a V12 and W. O. Bentley, after designing a long line of four- and six-cylinder engines, did a high-revving rather torque-lacking 4.44-litre V12 for Lagonda, with valve-gear similar to the new Jaguars, just before another war started. Since the war the V12 has become the hallmark of Ferrari and Lamborghini.
From the historical viewpoint the V12 is well established. But it was never as popular as the eight. In 1931 23% of the cars you could buy here had eight cylinders; only 1.56% were V12s. Today the V8 is universal in America, even for cars of up to 7-litres, and this number of cylinders suffices for the 6.7-litre Rolls-Royce/Bentley engine.
So the question may be asked, why have Jaguar gone to a dozen? The engineers responsible, Walter Hassan, OBE (ex-Bentley, ERA, SS, Jaguar and Coventry-Climax) and Harry Mundy (ex-ERA, BRM, Autocar and Coventry-Climax), say the V12 gives perfect balance, thus outstandingly smooth-running, and a high crankshaft speed, hence a safe high-power potential with reduced torque fluctuations. But they do not ignore the prestige value of having lots of cylinders, saying that it is Jaguar’s intention to widen the availability of the Ferrari/Lamborghini kind of engine, “achieving by use of the very latest machine tools a production volume which will bring this outstanding concept to buyers of competitively-priced cars”. However. Jaguar’s claim that they are about to bring “the magic world of twelve-cylinder motoring to a far wider cross-section of automobile connoisseurs than ever before” conflicts with their stated initial production rate for the new engine of some 9,100 a year, remembering that 21,000 Lincoln Zephyrs were sold in 1940 alone. This Lincoln engine had affinities with Ford’s V8 which first brought smooth-running, impressive torque and eight-cylinder charm to the masses and must be regarded as one of the cleverest automobile power units of all time…
Prestige certainly comes into V12 motoring. Daimler divided the radiator of their “Double-Sixes” down the middle to signify 12 cylinders and Hispano-Suiza cleverly refrained from putting their name on any part of their superb V12. Many luxury cars had double-barrel names to increase their snob appeal—Rolls-Royce, Hispano-Suiza, lsotta-Fraschini, Delaunay-Belleville, Sheffield-Simplex, etc.—but if Jaguar is no longer the SS-Jaguar, they can now at least display a V12-badge on the E-type.
Reactions to such an adventurous step-forward are bound to be mixed. Some will mourn the change from twin-cam head, the Jaguar hall-mark since W. M. Heynes introduced the brilliant XK engine in 1948 (although this is still used for the XJ6 saloons and Daimler Sovereign and is an alternative to the V12 for the E-type) and may even wish that the Heynes/Bailey 5-litre 4-cam petrol-injection 500 b.h.p. V12 engine which preceded the Hassan/Mundy V12 in the experimental shops could have gone into production.
Surprise is bound to be expressed that this CC-like Jaguar engine relies on one o.h.-camshaft per bank and a line of vertical valves above shallow wash-basin piston crowns, after all those decades of drooling over twin-cam hemi-heads. There may even be disappointment that the publicity top-speed figure for the bigger Series-3 E-type is 150 m.p.h., exactly the same as was claimed for the original E-type 10 years ago. In the 1970s one might expect the quoted maximum for a 5.3-litre V12 sports car to be 170 m.p.h. or thereabouts. One will also want to know about fuel consumption; some V12s have been notoriously thirsty.
However, the proof of the pudding is in the eating and Jaguar are clearly very anxious that their new recipe will prove digestible. They have spent £3 million tooling up to make the advanced and technically-exciting new V12 engine. They are spending much money on exhaust pollution research. If the world does not want big-engined twelve-cylinder cars Jaguar has no economy model to fall back on. So it is important for the V12 Jaguar to succeed and we wish Sir William Lyons, his technicians, workers, publicity staff, distributors and dealers the best of luck in this brave venture to supplement with a unique new power unit the successful Jaguar XK engine, of which more than 370,000 have been made. It is apparent that Jaguar regards this new car as one which should appeal to enthusiastic drivers of the kind who read Motor Sport and that, at least, is a good start!
Let us hope that, in the V12, Jaguar has found another “special kind of motoring which no other car provides”, to quote a Jaguar slogan, a car from which British Leyland and her export markets will benefit mightily, to the ultimate good of us all.