At the House of B.M.W.
If you join the main autobahn that makes a complete circuit of Germany, and drive round it until you arrive at the far southeast corner, you come to the Bavarian town of Munich, famous for its beer, a gigantic fiesta during October, an old church with two towers surmounted by strange globular domes, and the Bayerische Motoren Werke. It was to this last famous place that I went, to see how the present-day B.M.W. car is built and also to try one of the products on a journey to Italy.
The output of the B.M.W. factory is nowadays concerned with the production of cars, motor-cycles and the scooter-car known as the lsetta, and they are all built under the same roof and on the same principles of production and accuracy. Naturally it was the cars that were the main interest during my visit, under the guidance of Dr. Fiedler, the head of the design department, but the fact that motor-cycles still play a great part in the factory's workings was shown by the array of pre-war racing and record-breaking machines in the entrance hall of the B.M.W. house. Later, in the experimental department, I was to see two new machines ready to attack world records in the solo and sidecar motor-cycle classes, using the 500-c.c. B.M.W. flat-twin, fuel-injection, racing engines.
The car production is working on a basic chassis design and two types of engine, from which a range of eight models is produced. The chassis frame is of large-diameter tubular construction, many of the tubes, including the main side-members, being of oval section and fabricated from sheet steel pressings welded together to form tubes. This frame is very wide, being the full width of the car at the seats and is immensely rigid, though not unduly heavy. At the front, double wishbone suspension is used, the lower wishbone pivot being coupled to a long torsion-bar running parallel with the main frame. At the rear a normal one-piece axle is used, fabricated from pressings, and this is suspended on very long torsion-bars running forwards, again parallel with the frame. Location of this one-piece non-independent axle is by the torsion-bar operating arms and a central A-bracket from the differential housing. Steering is by a form of rack and pinion, where the rack is formed in a semi-circle, enclosed in an oil-filled box. The large five-seater saloon body is made from sheet steel pressings welded together, while the floor is welded to the chassis frame, giving increased rigidity. Of all the sections that form the body, the largest single pressing is that of the roof, and in the construction of the body both gas-welding and electric spot-welding are used.
Into this chassis-body combination is fitted one of two types of engine, a six-cylinder or an eight-cylinder, the latter being of vee formation. In order to accommodate these two very different types of engine the four-speed gearbox is mounted as a separate unit and coupled, by a short shaft, to whichever engine is used. The sixcylinder is an in-line o.h.v. pushrod unit, of 2.1 litres, giving 72 b.h.p., and is virtually a re-designed pre-war Type 326 engine, kept in production in order to produce a cheaper B.M.W. The main production in the engine department is concerned with the V8, and in standard form this is of 2.6 litres capacity, giving 95 b.h.p. This is in every way a very modern power unit, and a closer look at its construction and design proved most interesting.
The angle between the two cylinder banks is 90 degrees and the eight cylinders are cast in one compact block, with wet liners. A single chain-driven camshaft runs along the vee of the block and operates the overhead valves by pushrods and rockers. An unusual arrangement here is that the rocker gear is mounted on long steel studs screwed into the crankcase, this allowing the aluminium cylinder heads to expand with heat without altering the valve clearances. The valves of each bank are in line and the sparking plugs are at an angle on the outside of each head. On to the top of the vee of the cylinders is bolted a single aluminium casting containing the inlet manifolds, and on the top of this casting is formed a platform to carry a double-choke downdraught carburetter in the centre of a circular seating to take an enormous combined cover and filter that covers the carburetter completely, including all the control rods and levers. In the main casting the inlet passages are so arranged that each choke of the carburetter feeds four cylinders, the complex layout being designed in conjunction with the firing order, with the result that the effect of two carburetters is obtained. This manifold casting is water heated and thermostatically controlled. The short stiff connecting-rods are mounted side by side on the crankshaft journals and the shaft itself is mounted in five plain bearings. An aluminium sump is fitted, containing the lubricating oil, and there is a tubular oil cooler situated in the water passage of the near-side cylinder block. This cooler comprises a tube running the length of the block, along which the oil is passed, and it is returned by way of another tube wrapped round the main one in the form of a spiral, the whole thing being immersed in the cooling water. This results not only in constant temperatures but also in more rapid warming of the oil to its working temperature. Every casting on the engine is aluminium and the result is a very light and compact unit, and it is notable for its smooth running. This smoothness is considered a vital factor in building these V8 engines, and each one is run on an electrical balancing machine after assembly, the whole unit being carefully balanced dynamically. This fine degree of balance is obtained for each engine individually by means of radial drilling of the crankshaft damper and the flywheel after the engine has been run and, then, before any engine is fitted to a chassis, it is run-in for two hours on a test-bed, final engine adjustments being made during a road-test of the complete car.
During the tour of the factory many things became obvious and the most important was the fact that the B.M.W. people make everything on their car, only relying on outside firms for such items as carburetters, electrics and tyres. All castings, forgings, pressings and stampings are done at the factory, as are wheels, gears, brakes and body pressings. The feeling of B.M.W. is that apart from the fact that a car called a B.M.W. should be made by them and not by a multitude of other specialist firms, and that by making everything themselves they can keep a more rigid control over the quality and finish of every part of the car, thus being able to guarantee the finished article. In addition, they were free from the complexities of the policies and troubles of outside firms and had only their own problems to worry about. On the question of costing one interesting item was revealed, and that was that the steering-column tube and bracket, and also the pendant pedals bracket and mounting, together with the hydraulic master-cylinders for brake and clutch operation, were all of magnesium made by die-casting; this type of construction and metal being cheap to produce in quantity. In the experimental department there was work in process on new rear-axle mountings, front suspensions, brakes, wheels, steering gear and so on, while next door was the test department. In here were machines for working suspension units to destruction, others for measuring brake loads and drum deflections, a machine for applying cornering forces to the pressed-steel wheels, chassis-frame twisting appliances, rear-axle bending machines, and, in fact, everything with which to ruin any part made by the experimental department before it is fitted to a test car, thereby saving much time as well as gaining a great deal of valuable knowledge. In a smaller workshop next to this test department was the racing motor-cycle department, where the record-breaking machines were built and where the B.M.W. road-racing motor-cycles are prepared, these machines having completely dominated the sidecar racing class during the past season, a province that was once the property of the Norton machine.
Having had a brief view of the workings of the Bayerische Motoren Werke, including the building of the Isetta and the 250 and 500-c.c. motor-cycles, all of which are built to the same high standards as the cars, I took a brief stock of the range of 1956 models in the car programme. The 501 is the large family saloon fitted with either the six-cylinder or V8-cylinder engine, the 502 is a de luxe version of the V8-cylinder 501 saloon, and in addition this luxury version can be obtained with the V8 engine enlarged to 3.2 litres, giving 120 b.h.p. These de luxe models have a much larger rear window, centre armrest to the rear seat, leather upholstery, polished wood interior trimmings around the doors and windows, and more stylish instruments as well as a much higher degree of finish to the bodywork in general. The 503 model has the same chassis frame but is fitted with a tuned version of the 3.2-litre V8, giving .140 b.h.p. This is obtained by fitting two double-choke carburetters, new inlet manifolds, larger valves and ports, different camshaft and higher compression ratio. This model is made with either a drophead coupé body or a fixed head, both being full four-seaters, with electrically-operated windows, and electrically-controlled hood on the drophead. The 505 is a special lengthened chassis fitted with the 120-b.h.p. 3.2-litre V8 engine and is intended to take specialist coachwork in the limousine category. Finally, and of especial interest, is the 507 sports-roadster, a very pretty two-seater on a short chassis, fitted with the tuned 3.2-litre engine, a five-speed gearbox attached directly to the clutch housing and operated by a short central lever. This model has larger brakes, with alloy turbofinned drums, higher rear-axle ratio and such items as knock-off splined hubs, competition screens, etc., are available as extras. Built essentially as a roadster and not a sports/racing car, the 507 is lavishly equipped inside the cockpit with radio, heater, large door pockets, lots of padding and thick carpets. Basically this model is fitted with a normal canvas hood, which together with wind-up windows of glass makes a very weather-tight closed car; however, a detachable hard-top, held by six, screws and two quick-action clips, is available, and this is made of aluminium, as is the rest of the bodywork, and the result is one of the nicest looking sporting roadsters yet seen. Having taken stock of this Munich car factory and its products, I borrowed a 501 model fitted with the V8 engine in order to make a short tour with some friends around Germany, Austria, Italy and Switzerland, and there being four of us the pile of accumulated luggage was most awe-inspiring. However, the large bulbous boot of the B.M.W. is very deep and the whole lot disappeared inside along with the spare wheel and a bag of tools and spare parts, such as fanbelts, plugs, spanners, water hoses and so on. The first impression was one of concern for the steering, for the king-pins had negative castor angle and this, together with the very light rack-and-pinion gear, gave a feeling that once the wheels were turned they would flop over to full lock on their own. The steering was so light and yet nicely positive in its feel that this free feeling took some getting used to. Subsequently it transpired that this fitting of negative castor angle has been dropped on the new models and half a degree of positive castor is now used. There is always a tendency to drive a car as fast as it will go and this V8 B.M.W. could certainly go fast, the smooth torque of the engine giving it excellent acceleration, so that it quite easily showed 160 k.p.h. on its speedometer (99 m.p.h.). The gear-change was the steering. column type, quite beyond reproach if you have the sort of arm and wrist that can grapple with an up-and-down movement behind the steering wheel, but personally I find my bone construction works much more smoothly on a conventional floor-mounted lever
On the first run with this car we went down into southern Bavaria, to the borders of Austria at the funny little town of Mittenwald, where it is claimed the first violin was born, and along winding narrow roads the car had a disconcerting habit of swooping about in the wrong direction at the wrong time as well as shrieking to high heaven on its tyres as soon as you saw a corner and took a firm grip on the large plastic-covered steering wheel. Over coffee in one of the picturesque cafés in this little fairy-tale town we gave the B.M.W. some thought and read through the very complete and well-produced instruction book. Our tyres were all good and pressures correct, at 25.6 lb. front and 24 lb. rear, but then we read a little footnote that emphasised the need to increase these to 31 lb. all round if the car was fully laden and to be driven fast. This we did and the result was an entirely different car from one that had been wallowy and sick-making like a bad American car, it could now be held round corners really quickly with a nice degree of understeer that would gradually disappear as the limit of adhesion was reached and change to a rear-end breakaway at the ultimate, but all the time with plenty of warning and control. The return run over the Bavarian Alps was most pleasant, and even while the driver was enjoying himself finding the car's limitations there was no undue discomfort to the passengers, who were admiring the mountain scenery, and the tyre noise was reduced to a small whistling that gave no impression of the rate of the cornering. This vast difference occasioned by the change in tyre pressures was quite in order with the steering and suspension characteristics of sensitivity, while the higher pressures had no effect on the comfort of the ride, even when the car was occasionally driven slowly.
The Editor has a "thing" about what he calls "garage cars," by which expression he refers to cars with a static character, ones that can be enjoyed in the garage as well as on the road, and in this I am in full agreement with him. These garage cars are ones that are different from the everyday run of mass-produced box-like vehicles, where everything conforms to a set pattern and the only way to discover what car you are dealing with is to look at the name on the front, though even some of the badges are losing character.
The 501 B.M.W. is essentially one of these garage cars, and while the rest of the party were busy looking at churches, monuments, panoramas and the like, which have become commonplace to me over the years; I could sit and enjoy the static-character of this B.M.W. There was a wonderful electrical system controlling the lights and horn, for example. A full-circle horn ring, operated by pressure from above or below, sounded dual horns, while the large wheel centre put the headlamps on full beam when it was depressed, providing the lamps-switch was in the side and tail position. This headlamp flasher is a "must" when motoring fast in Italy or on the German autobahns, and the sooner it is recognised in Great Britain the better. The lamps-switch was a two-position pull knob, the first position putting on side and tail and the second the headlights. A small lever on the left of the steering column put the lamps to dip, so that an up-and-down flicking of this lever would flash a warning at crossroads at night. In addition, the wheel centre button also brought the full-beam filaments of the lamps into play, so when on dipped lights a pressure on the button added the full power of the full-beam filament in addition — useful in an Italian "light-flashing battle" with some of the lorries and buses. By turning the light-knob clockwise a three-position switch for the instrument lighting was brought into play, giving off dim and bright alternatives. The self-parking electric wipers were operated by another dashboard knob, and by pulling it into its second position water-squirts were switched on automatically, giving jets of water at timed intervals, a brilliant innovation of immense help when overtaking traffic on muddy reads. The selection of dials in front of the driver comprised oil pressure and water temperature on the left, speedometer, with mileometer and trip, in the centre, and on the right a petrol gauge with headlamp high-beam indicator on one side and ignition warning light on the other. Of all the cars I drive about five per cent. have an intelligently placed headlamp-beam indicator, most of them being so placed that they shine straight between the driver's eyes, or else are so bright that they illuminate the interior of the car, while nearly all of them have powerful bulbs and magnifying-glass-covers. The B.M.W. is one of the five per cent., the light being a dull matt blue, perfectly obvious at all times without causing any reflections. It was interesting to notice the same arrangement of blue light on a pre-war B.M.W. borrowed from a friend shortly after this test. On the right of the facia, this being a left-hand-drive car, was an enormous glove compartment, so big that small items were continually being lost in it, and it was fitted with a very firm lid that could be used as a picnic table when eating a snack meal on the move.
Over the glove compartment was a useful grab rail for the passenger, while in the centre of the top of the windscreen was a neat clock, easily read by all the occupants during the day, but quite useless at night. The rear-view mirror was rather small in its vision but was that excellent type where the mirror is fitted behind a piece of plain glass, and at night the mirror can be flicked down a few degrees, eliminating dazzle from following lights, while the glass still reflects enough to be aware of following vehicles.
On the floor by the front of the driver's seat was a petrol tap giving three positions, off, on and reserve, easily reached even at high speeds. Other interesting items that pleased while having a prowl round the car were a light in the choke-control knob that lit up when the choke was in use, a hand-throttle that subsequently proved to give a speed of 45 m.p.h. in top gear, quarter windows in the front doors that could be opened beyond top-dead-centre and so produce a really powerful blast of cold, air, though in this position the driver could pinch his fingers between the window and steering wheel when winding the car round a sharp corner, and opening rear quarter windows to assist the ventilation system.
The ignition key, in the facia panel, has three positions from "off," the first operating the electrical circuits for various accessories, such as ventilation blower, the second opening the ignition circuit and the third, against a spring loading, actuates the starter. This, means that to start the engine you merely turn the key right round to the third position and then let go when the engine fires. When the bonnet or boot lid were opened — both balanced against springs — really powerful inside lights were automatically switched on, the air ducts from each side of the radiator grille fed cold air to the interior system, and in front of each duct was a removable filter. The radiator drain tap, easily accessible when the bonnet was raised, was made to take a rubber pipe for draining into a container
When the doors and boot were locked the push-button opening mechanism was made inoperative, the button going in and out freely. The doors stayed in the fully open position by means of over-centre catches, and gave plenty of space for entry and exit. The rear seat had side armrests that folded and there was an enormous shelf behind the seat squab. The front seat had normal sliding adjustment and also that excellent German fitting of lever-operated seat backs that could be let down to the near horizontal, making quick half-hour naps by the roadside a pleasure. On this cheaper B.M.W. model the seats were cloth covered and were so soft as to be impossible on a long run, the occupants being tired out after 300 miles on winding roads, as the softness of the seats gave very little support and the cloth covers held one's clothes, allowing the body to move about inside them. During a day's driving through the Dolomites at quite low speeds due to rain and mist, one member of the crew found his trousers back to front due to this clinging property of the seat covering. On the 502, of course, this complaint would not arise, the seats being much firmer and leather covered, and the torsion-bar suspension is amply supple enough to keep the ride comfortable.
Where this V8 B.M.W. really came into its own was on the German autobahns, for it would go up to maximum speed with no sound from the engine to give any indication of the power being developed. Wind noise with the windows all shut was negligible. There was a certain amount of road noise audible, possibly reduced if an undertray was fitted, but fully laden the car could be kept on full throttle for mile after mile, showing no signs of distress. After a visit to Stuttgart a return was made to Munich by way of the autobahn and in the dark the speedo. was kept on 170 k.p.h. for most of the way, often going to 180 k.p.h. (112 m.p.h.), the journey taking just over two hours. The lights were adequate for such speeds and the comfort such that all except the driver slept soundly. though there was a peculiar "swing" as the car crossed the longitudinal joins in the concrete sections of the road. Due to having the gearbox separate from the engine there is a hump on the front floor and this gets in the way of the driver's accelerator foot, limiting it to one not-very-comfortable position, while the pedal itself, hung front the top, is too high off the floor for most people. On flat-out driving this peculiar position of the accelerator pedal is not noticeable; it is only on part openings, and this makes cross-country journeys rather tiring.
The all-synchromesh four-speed gearbox has a fairly close gap between second and third, making acceleration in traffic very impressive, but a long gap between third and top. However, the excellent torque curve of the engine makes top-gear motoring a pleasure, while use of the lower gears in mountains enables a real surge to be obtained between hairpins. With the light steering and a truly enormous lock, together with synchromesh first and second gears, a crossing of the Swiss Alps by way of the little-used Splugen Pass became immense fun. Stepping to admire the mountain scenery from a great height the good lock and powerful parking brake, operated by a pull-out lever of immense travel, enabled the car to be placed neatly into a small space even on a steep slope.
Although the B.M.W. saloon is a large car and to some people it has an appearance of ungainliness, it is one of the easiest cars to drive and, whereas some cars take a few hundred miles to get used to this one made the driver feel at home within the first mile or two. The size was never any embarrassment, even amidst the cut-and-thrust of traffic in Milan, while the wonderful surge of power from the engine in second gear soon showed the Italians where they got off, even when we were fully laden. While this car proved to be in no way an outstanding vehicle, viewed through an enthusiast's eyes, it was a first-class example of a modern family saloon, in which a great deal of thought had been given to the wishes of the driver who enjoys motoring as well as those who merely want a travelling lounge. There is no doubt that the men behind the B.M.W. design are practical motorists, while the standard of workmanship is absolutely typical of a German car factory. Over a distance of 2,500 miles all the car needed was petrol and the aforementioned careful attention to the tyres. The amount of petrol depended on the way the car was driven, normal touring with 70-80 m.p.h. cruising giving as much as 19 m.p.g., but this dropped to 15½ m.p.g. when held on full throttle on the autobahn for over one hour. and the tank capacity limited the range to 240 miles under these conditions. For such an obvious long-distance, high-speed touring car the range should be well over 300 miles and a larger tank capacity would be a benefit in the design. As regards the shape of the body on the B.M.W. saloon, it is a matter of taste whether it appeals to the eye or not, but whatever view is taken, it cannot be denied that it is refreshingly different in these days of stereotyped saloon-car bodies. In spite of being the cheapest version made by the B.M.W., the car on loan stood up to the severe test of fast motoring it received with no fuss, and the only item to be found wanting were the brakes. Driving on fast main roads, in the 70-80 m.p.h. region, continually passing other vehicles and frequently making rapid stops when oncoming traffic closed gaps, it was found that the brakes had a habit of suddenly changing their character. After applying the same pressure four or five times for regular reductions of speed in quick succession, the next application of the same pressure produced no retardation at all. At first this made one lose confidence in the car, but when very hard pressure was applied it was found that the wheels could still be locked. The trouble was that when the brakes overheated, the amount of pedal pressure for the same braking effort was increased by about three times and without any previous warning. That this problem a stopping a heavy fast car is well to the forefront in the design department was seen by the new finned steel drums on the 503 and the alloy ones on the 507. While this change of pressure was unpleasant, it was preferable to some other makes of car on which the brakes disappear altogether until cool. During some tests of crash-stops from 100-0 m.p.h. the B.M.W. brakes would not change character, even after repeated applications, the time to accelerate from 0-100 m.p.h. being sufficient to let them cool off.
After sampling the 501 saloon the feeling was that the most outstanding part of the car was the new V8 engine, and thoughts turned to the possibilities of the sports version, so that after returning the borrowed car to the factory, the opportunity for a short run round the houses in the 507 was eagerly taken.
In every way a two-seater roadster, full of luxury and comfort, there is nothing roadster about the performance of the. 507. The acceleration is impressive by any standards, for the car weighs 22 cwt., the engine develops 140 b.h.p., and it has an excellent torque curve. On a dry road a jab on the throttle in first gear would provoke furious wheelspin, which was impressive to say the least for such a beautifully-finished two-seater. Not being able to go over 50-60 m.p.h. in the town the cornering could not really be tried, but the response to the controls was very good and the car felt nicely in "one-piece." Leaving the House of B.M.W. about to attack the World's Sidecar Record, with a speed around 170 m.p.h., on the Munich-Nuremberg autobahn (probably an accomplished fact by the time these words are in print), I left Munich feeling that though B.M.W. do not raise a great publicity voice throughout the world, like some firms, there is much of interest going on down at the south-east end of the autobahn ring, and in their 1956 range of cars they have some very interesting vehieles. — D.S.J.