BMW celebrates 90 years of innovation

The Bayerische Motoren Werke (Bavarian Motor Works) was founded in July 1917 as a manufacturer of aircraft engines, and following the Armistice of November 1918 was forced to branch out into motorcycles, braking systems and large truck engines.

In 1923 BMW produced its first complete motorcycle, the 500cc side-valve IZ 32 - two of its features, a horizontally-opposed flat twin engine and shaft drive, are still found on BMW motorcycles today.

The engines found their way into several German light cars, including the three wheeled Wesnigk, the two wheeled Mauser Einspurwagen, the BZ and the Maja. BMW experimented with a car using this flat twin engine, but did not proceed with it, instead finally diversifing into car manufacture with the licence built British Austin Seven, which was made by the Dixi car works, when it acquired the company in 1928.

Initially they were badged as BMW 3/15s and a total of 15,948 were made. Their successor was the 3/20PS, a little larger in engine capacity but all new, with a central backbone frame and swing axle rear suspension. This and other similarities were evident on the Mercedes-Benz 170, with the two companys sharing several directors, while many Mercedes-Benz dealers also sold the small BMW as well.

Within just one year, the BMW 3/20 PS was available with a new power unit, the new 20hp 782cc engine featuring overhead hanging valves and running much more quietly than its predecessor. The seats, motoring comfort and lines of the new car were also far more harmonious and modern than its predecessor.

The BMW 303: the first six-cylinder. In 1933 BMW introduced the 303, a small six cyclinder car which began the pattern of BMWs for the rest of the 1930s. The tubular frame was retained up to 1936 and engine capacity rose to 2.0-litre on the 326, 327 and 328 and to 3.5-litres for the 335, the last pre-war design.

The 303 was the first BMW to feature the kidney radiator grille. Within the engine compartment the new model had a 1.2-litre six-cylinder in-line engine developing maximum output of 30hp. The engine was based on a four-cylinder introduced a year before and differed primarily through the combination of the crankcase and cylinder block to form one complete unit. Further highlights were the camshaft fitted beneath the engine block and the tappets operating the valves in vertical hanging arrangement via rocker arms. Both the intake and exhaust pipes were on the same side. A feature quite unusual today was the varying gaps between cylinders: the distance between the second and third, and the fourth and fifth cylinder were larger than the other gaps between the cylinders, with this extra space being required to accommodate the crankshaft and camshaft bearings.

The crankshaft not using any counterweights therefore ran in four bearings, just like the camshaft. However this was not the main reason for this rather distinctive design. Rather, the crucial factor was that back then the crankshaft was assembled together with the connecting rods and pistons as one completely prefabricated unit. And since the pistons had to be fitted into position from below, the main bearing supports for the crankshaft were not allowed to extend into the cylinder contours. Hence, the only option was to accommodate the main bearings between cylinders further apart from one another.

The BMW 326: frame and body welded to form one unit.

Two years later BMW launched a new top model, the BMW 326. It was acknowledged as one of the most advanced large scale production cars of its time. It was in fact the first BMW to feature a body shell welded to the frame, doors hinged at the front, a hydraulic brake system and the spare wheel housed beneath a cover on top.

Proceeding from a newly developed low-bed box frame with a torsion bar suspended, low noise rear axle, as well as transverse leaf springs on the front axle moved further down, BMW's engineers had created an all new mid range model. The engine was also a new two-litre six-cylinder with two carburettors and maximum output of 50hp conveyed to the wheels by a partly synchronised four-speed transmission even featuring a free wheel function in first and second gear. Top speed of the BMW 326 was an impressive 115 km/h.

From 1935 to 1939 several models of BMW were sold in Britain under the name Frazer-Nash BMW.

Production of cars for civilian owners ceased in September 1939, but BMW continued to produce small numbers of 321s, 326s and 335s until May 1941, after which motorcycles were the only road vehicles it was permitted to build.

After the war BMWs Munich car plant was in ruins and its Eisenach plant was lost to East Germany. Motorcycle production returned in 1948, with strongh sales financing the introduction of a new car in 1952, the 501 saloon.

The BMW 501

Although relatively "classic" in its design and styling, the 501 featured a number of interesting technologies.

The two half shafts at the front were each mounted on two triangular track control arms running in needle bearings. This low friction bearing technology ensured a particularly sensitive response on the part of the progressive springs and suspension made up on each side of a longitudinally arranged, extra long torsion bar.

The arrangement of the dampers was likewise quite unusual: fitted at the outside on the lower triangular arms, the dampers extended upwards in an inclined position, coming to rest inside on the upper track control arm. This avoided any contact with the sprung body and prevented even the slightest transmission of noise.

Focusing on the steering, the engineers in Munich introduced a very special idea on the BMW 501, applying the principle of rack and pinion steering to a crown wheel segment in the interest of maximum steering precision.

The oil reservoir for the steering served at the same time to lubricate all other front axle components, which therefore remained independent of the regular central lubrication. The rear axle, as all testers agreed at the time, was the "ultimate level of perfection in the development of the live axle", torsion bars acting on the axle right at the outside via spring arms serving here to provide the necessary suspension effect and at the same time giving the car its longitudinal guidance.

Even the gearbox with gears being shifted straight from the steering wheel was arranged in a different position: instead of being bolted directly to the engine, the gearbox with its four all synchromesh gears was housed beneath the front seats and connected to the engine by a short propeller shaft.

The advantage of this particular arrangement was that the footwells remained largely free, without being impaired or cluttered by a voluminous transmission housing. A further benefit was that the engine mounts did not have to be redesigned for maximum torque from the transmission, meaning that the engine was able to rest on unusually soft and smooth mounts. The bottom line therefore, was that the 65hp six-cylinder, a modified version of the engine already featured in the BMW 326, was exceptionally smooth and refined in the BMW 501.

1954: introduction of the world's first light alloy eight-cylinder.

The BMW 501 nevertheless only paved the way for BMW's most spectacular innovation in the '50s. The first series-production light alloy engine in the world and the first German eight cylinder after the end of the War launched in1954. Weighing in at 210 kg, the 2.6-litre power unit in the BMW 502 was just 28 kg heavier than the six-cylinder in the 501. The V8 initially produced 2580cc and later 3168cc.

There were also sports models with the 503 and the excellent 507 of 1957. While technically innovative these expensive models were slow sellers, and it was in complete contrast that the BMW-Isetta - an Italian designed bubble car built under licence from Iso of Milan and powered by BMWs 245cc R25 motorcycle engine that kept the company solvent, selling 161,728 between 1955-1962.

Despite these sales BMW was in major financial strife in the late 1950s due to a disasterous slump in motorcycle sales. It sold its Allach factory to truck maker MAN and the government invested 10 million marks in BMW in 1959. A plan was set in motion whereby there would be joint ownership of BMW by Daimler-Benz and a consortium of banks, but this was rejected and the company survived with a further cash injection from MAN.

The turning point came with the introduction of a new medium sized car in 1961, the 1500. This initiated a series of high quality four cylinder models overthe next decade.

The BMW 1500 made its debut at the Frankfurt Motor Show in 1961.

It was powered by a 1.5-litre straight four developed under the guidance of Alexander von Falkenhausen, at the time BMW's engine wizard. Maximum output of 80hp was sufficient for a top speed of almost 150 km/h.

By 1963 BMW was again making profits and in the same year purchased Hans Glas GmbH, maker of Goggomobil and Glas cars. Most models were rebadged as BMWs. The 1300GT was powered with a bigger BMW 1600 engine and rebadged 1600GT. The 2600GT lost its Glas-derived 2.6lt V8, replaced with BMW's own 3-litre V8, although, curiously, it continued to wear a Glas badge until 1968.

The first turbo made in Europe.

With its substantial power reserves, the four-cylinder used in the 1500 opened the door for an increase in performance. Introduced in 1970, the 130hp BMW 2000 tii became the first BMW with mechanical fuel injection, setting a new benchmark in the two-litre class.

The debut of the BMW 2002 turbo three years later was even more spectacular, this 170hp top performer in the 02 Series reaching a maximum speed of 210 km/h with its 170hp power unit. Built for a period of just 10 months, the 2002 turbo was available exclusively in white and silver, the short production life of the fastest and most powerful BMW 02 being a result of global decisions taken in the oil market. In response to threats by the oil exporting countries, the Western world imposed speed limits and bans on driving, with the price of fuel in Germany rocketing up, making life very difficult for a car as technically sophisticated and progressive as the 2002 turbo. For the turbocharged BMW was once again an outstanding trend setter, being the first production car in Europe to feature exhaust gas turbo charger technology.

As early as 1968 BMW's engineers had derived a second engine family from the four-cylinder destined to really characterise the image and reputation of the brand. The straight six power units featured in the BMW 2500 and 2800, once again taking the company back into the market of large saloons and coupés. Fitted at an angle of 30°, these power units featured a crankshaft running in 7 bearings and controlled by 12 counterweights for superior smoothness free of vibration. A further feature was the overhead camshaft likewise helping to give BMW's six cylinders the "turbine-like" smoothness for which they subsequently became so famous.

One of the technical innovations on the two engines boasting the same design concept was the so called "triple-hemispherical swirl-action combustion chamber" configuration literally cut into the pistons. This special geometry served to generate exactly the right swirl effect, concentrating the fuel/air mixture around the spark plug. The result was a very effective but at the same time soft and smooth combustion process. Maximum output of the 2.5-litre was 150 hp, with the 2.8-litre developing an even more significant 170hp – enough to catapult the BMW 2800 into the exclusive elite of 200 km/h cars. This new engine concept stood out from the start as a genuine role model not only on account of its power and performance, but also because the new engines were at the same time economical and robust.

The BMW M1

The BMW M1 clearly proved the great potential of the six cylinder power unit in 1978. This low slung mid-engined sports car was powered by a 3.5-litre straight six delivering 277hp to the rear axle. Code-named the M88, this outstanding power unit was based on the M06 engine built in a large production series and featured the four-valve cylinder head carried over from the racing engines in the BMW CSL lightweight coupé. Offering this kind of technology, BMW took on a leading role in the introduction of four-valve engine concepts.

The BMW 524td: setting a milestone in the diesel market.

A genuine revolution in the history of BMW was the decision to enter the fiercely contested market of diesel cars, developing a brand new generation of engines in the process. The first model produced in this initiative was the BMW 524td launched in June 1983, BMW living up to the challenge to build a diesel engine combining the advantages of diesel technology with the features so typical of BMW such as dynamic performance. The result was the BMW turbo diesel based on the existing straight six power unit displacing between 2.0 and 2.7-litres. Featuring turbocharger technology and large cross sections on the intake and outlet valves of the engine displacing 2.4 litres, the new diesel was able to develop a substantial 115hp maximum output. The turbulence chamber combustion process enhanced to an even higher standard than before offered ideal conditions for superior fuel economy and low combustion noise.

As an alternative concept, BMW also offered an innovative engine with gasoline technology. This new power unit was featured in the 525e entering the market in 1983, the letter "e" standing for "eta", the symbol for efficiency. This 2.7-litre six cylinder was optimised for supreme torque and economy, developing 122hp maximum output, but nevertheless consuming just 8.4 litres regular fuel on 100 kilometres.

Rationalisation

For the 1970s and the 1980s, BMW rationalised its model ranges. The 3 Series would be medium sized cars with four cylinder 1.7 or 2.5-litre engines, the 5 series of four door sedans with engines from 1.7-litre four to a 3.4-litre six, the 6 series of coupes with 2.8 or 3.4-litre six cylinder engines and the luxury 7 series saloons. There are also high performance M models.

The BMW 750i: twelve cylinder with the most advanced technology.

1n 1987 the BMW 750i made its debut as the first twelve cylinder saloon built by a German manufacturer since the end of the ‘30s. This new BMW flagship nevertheless remained relatively modest from outside, standing out from the other models in the BMW 7 Series only through its somewhat wider radiator grille and the wider power dome on the engine compartment lid as well as square instead of round tail pipes.

The BMW V12 was developed with the objective to superior performance, compact dimensions, all round economy, and exemplary emission control. With maximum output of 300hp, together with peak torque of 450 Nm, the new V12 out-performed comparable engine and vehicle concepts in the market at the time.

The BMW Z1

In 1988 BMW for the first time offered the BMW Z1. This unique model was conceived and built by BMW Technik GmbH as an example of alternative body engineering, the company taking a new approach in designing and building this new car. As an example this two seater featured a monocoque-like, unitary frame structure made of corrosion free steel plate, while the body shell was made of thermoplastic segments recyclable individually as required.

A highlight of the very modern body design was the side sections retracting electrically into the car and taking the place of conventional doors.

Only the powertrain came from BMW's "regular" production models, the Z1 featuring the 170hp six cylinder carried over from the BMW 325i and giving this roadster quite unique to this day a top speed in excess of 220 km/h.

The BMW Z8

Entering the year 2000, BMW introduced the Z8. It featured a trend setting spaceframe unitary aluminium body structure. Built as a kind of truss structure, the space frame incorporated high strength structural aluminium plates filling in the space between generously dimensioned extrusion pressed profiles serving as a stable "skeleton".

From VANOS to VALVETRONIC.

In 1992 BMW introduced infinitely variable valve management – double-VANOS – as a world first in the BMW M3. The particular advantage of this control system is that it adjusts valve timing on both the intake and outlet valves infinitely to the engine's running conditions via precise angle control of the cam-shafts, regardless of the position of the gas pedal and engine speed. In practice this means substantial torque at low engine speeds and superior power in the high speed range. And keeping the amount of unburnt residual gases to a minimum, double-VANOS also serves to improve the engine's idling qualities.

Special engine management control maps for the warming up process serve in addition to enhance the effect of the catalytic converter, with all of these functions being masterminded by Digital Motor Electronics (DME).

The efficiency of BMW's power units was further enhanced to an even higher standard by the introduction of VALVETRONIC in 2001. VALVETRONIC is a valve drive system with fully variable lift management of the intake valves, engine output being controlled by infinitely variable intake valve lift without requiring the throttle butterfly previously inevitable on an internal combustion gasoline engine. The intake valve lift function introduced in this way controls the amount of air drawn into the engine, keeping power loss to an absolute minimum (air volume control).

On the road VALVETRONIC technology gives the BMW driver enhanced fuel economy, reduced exhaust emissions and, at the same time, even better response and a higher standard of running smoothness.

The BMW six cylinder: the only engine in the world made of composite light alloys.

Introducing the first production engine with a composite magnesium/aluminium crankcase, BMW hailed yet another pioneering achievement in 2004. Thanks to this unique casting technology developed by BMW inhouse and now applied consistently in production, the straight six weighs a mere 165kg.

This was followed in February 2006 by the Twin Turbo power unit featuring High Precision Injection, again giving BMW a leading position in turbocharger technology on large scale production gasoline engines. Together with BMW's straight six diesel featuring Variable Twin Turbo technology, this power unit ranks right at the top in the international market.

Future efficiencies

This year BMW introduced an all round concept of intelligent energy management with hybrid functions, features such as Brake Energy Regeneration serving to enhance the level of efficiency, in this case by generating electrical energy for the car's on-board network solely while the engine is in overrun and during application of the brakes. The Auto Start Stop function, in turn, also serves to use fuel with maximum efficiency, optimising fuel economy on the manual gearbox version of the BMW 1 Series in conjunction with BMW's new four cylinder gasoline and diesel engines. To benefit from this new function, all the driver has to do is shift to neutral when coming to a halt at the traffic lights or in a traffic jam and let go of the clutch pedal. This automatically switches off the engine, which is immediately activated as soon as the driver presses down the clutch pedal again. Using this Auto Start Stop function, the driver is able to reduce fuel consumption during standstill of the car to zero.

Over and above Brake Energy Regeneration and the Auto Start Stop function, the new four cylinder power units designed from the start for maximum efficiency help to further optimise fuel economy in general.

In series development, BMW is already in the process of electrifying the drive- train all the way to full hybrid technology. So based on an active transmission combined with intelligent energy storage, a full hybrid will be presented to the public within the next three years.

Since even vehicles with this technology will still emit CO2 while driving, BMW EfficientDynamics focuses in the long term on the use of hydrogen recovered in a regenerating process.

Indeed, BMW has already become the first car maker in the world to launch a luxury saloon with hydrogen drive built in series production – BMW Hydrogen 7, an absolutely unique car emitting virtually nothing but vapour when running in the hydrogen mode. The particular feature typical of BMW is that BMW Hydrogen 7, benefiting from its supreme 12-cylinder power unit, does not require the driver or passengers to make the slightest concession in terms of motoring comfort, performance and reliability.

And since the car is also able to run as an alternative on conventional premium fuel, it guarantees unrestricted mobility also beyond the range of hydrogen filling stations.

Introducing this practical solution, BMW is clearly demonstrating not only its leadership in technology in the area of future drive systems, but also in the integration of hydrogen drive into a vehicle concept clearly proven in practice. This obviously sets the foundation for an alternative to conventional drive technology accepted in the market and readily available to the customer.

The launch of BMW Hydrogen 7 is a milestone en route to a new age of mobility independent of fossil fuel for the entire automotive industry. And in this way, BMW is once again proving the unique innovative power and potential of an equally unique brand.