Modern Motoring

Northern Advocate, 22 April 1939, Page 6 (Supplement)

Modern Motoring

Germany’s Contribution To Popular Motoring

The German technical press has recently printed complete and illustrated description of the Hitler “Volkswagen” (People’s Car), which is already known throughout the Reich as the “K. D.F.” car—these being the initials of Kraft dudch Freude, or “Strength thr cugh Joy.” It is additionally announced that communal garages are being built to house the cars wherever traffic considerations make it impossible for the car to be parked outside the owner’s door, and that the fee for the use of such garages will be 7/6 a month. The most interesting component of the car is naturally its engine, which is of the type commonly known as a “flat four,” or more accurately, as a double horizontally opposed twin-cylinder. The air-cooled cylinders are cast individually, and assembled with inter vcning air spaces, but each pair of ■cylinders share a common combustion head. The overhead valves are operated by push rods.

Since this engine is mounted under cover at the rear c£ the chassis, special precautions are essential for cooling. The cylinders are very heavily finned, and a high-speed centrifugal blower, mounted on the central crankcase, delivers air blasts to the heads by means of ducts. But a high percentage of the surplus heat is removed by means of the lubricating oil. A large volume cf oil is carried in a heavily ribbed sump, and a special oil cooler is mounted on the crankcase. The oil is circulated at high rate by a powerful pump, and this provision is probably at least as vital to the cooling as the air currents induced over the cowled cylinder heads by the blower.

Soon after the Great War. Granville

Bradshaw produced in England an air-cooled flat twin car engine of 12 h.p., and also experimented with an “oil-ccolcd" engine. The Volkswagen layout is a logical development of the Bradshaw idea, which came to an untimely end in the post-war slump. A liftable panel in the tail of the K.D.F. renders most of the engine details reasonably accessible. Severe and prolonged tests in the hillier areas of Germany have proved that Dr. Porsche’s cooling system is equal to any demands likely to be made upon it.

combine the two methods of cooling used by Dr. Porsche (induced air currents and oil-cooling), and their sponsors lost interest in them for the further reason that their engines were mechanically noisy. Their lack of a water jacket, which exercises a damping effect on sound, causes gear noises, valve clack, tappet impact, and other internal sounds to swell into an unpleasant orchestra. Dr. Porsche has eliminated this objection by locating his air-cooled engine at the tail of the car. where the noise may irritate other road-users, but is largely swept away from the occupants of the noisecreating car.

It is interesting to recall that at least three British motor-cars with aircooled engines made their appearance after the war. All of them were prone to over heat, because they failed to

The method employed for balancing the engine is not disclosed in the

Hints, Information and Advice for Owners and Drivers

photographs so far available; it will be interesting to see how far it corresponds to the extremely ingenious system applied by Mr George Brough and Mr F. W. Dixon to the flat four engine mounted on a motor-bicycle at the last Earls Court show in London. It is now evident that the design exhibits no startling originality in the shape of really novel components, but rather an extreme ingenuity in combining ideas which had hitherto only appeared in isolation.

The way in which weight has been reduced is, however, particularly remarkable; according to the German press the car weighs no more than 12cwt complete. On this very low figure depends to a great degree its modest fuel consumption of 40 miles to the gallon, its fast climbing powers, and its good speed on the level (variously stated as 70, G 5 and 60 miles an hour). It was staged at the Berlin Motor Show /February 17 to March 5), where it was eagerly inspected by countless pilgrim engineers from

every motor manufacturing company in the world. There are definite hints that the Italian Government are exploring the possibilities of producing a small popular car under similar policies. Some controversy exists as to the true price of the K.D.F. Perhaps in teeth of obvious difficulties in converting German marks to sterling, the fairest method of estimating its price is to say that for a resident in Germany the car costs about two-thirds of the sum previously asked for the cheapest German small car. But the German predecessor, like the cheapest English car. was an open two-seater of exiguous dimensions, whereas the K.D.F. is nearly 14ft long, over sft wide and has a two-door saloon body So there is a great jump in size and equipment, as well as a marked drop in price.

Taking the true exchange rate between England and Germany at 12 marks to the £, the K.D.F. must be pictured as costing about £B3, compared with £IOB, the English price of the cheapest English small car (a seven h.p. open two-seater). It is conceivable that the K.D.F. will exert a marked influence on design. It proves that air-cooling is entirely practicable, provided that induced air currents are combined with oil-cooling (the oil cooler is a vertical “tower” radiator, set on the crankcase, and measuring perhaps 15 inches high by four inches square). The American Franklin six-cylinder car sold by many thousands after the war without the aid of air-cooling. It passed out of existence mainly because it was mechanically much noisier than its water-cooled rivals, the various internal mechanical impacts creating much additional resonance in the absence of the damping effect of a water jacket. The rear engine position largely counters this difficulty, and we may yet see air-cooled cars of 20 h.p. or more. They would be lighter than water-cooled chassis. They might create rather less trouble, for pumps and radiators are not cheap, and sooner or later demand repairs.

But on the whole it seems probable that the adoption of air-cooling for the K.D.F. has been dictated by the winter garaging factor (a factor not arising in most of New Zealand, particularly Northland, which does not know the snowy Continental winters), and that where a frostproof garage exists the verdict would normally be in favour of a water-cooled engine. JAPAN Japan is trying to popularise charcoal for vehicle-fuel purposes. Fivethousand lorries and a thousand cars have already been adapted to run on it.