A BMW Wartburg Roadster ...
The automotive history of BMW commences at a rather late date; specifically, on the 14th November, 1928, the time at which the "Bayeerische Motoren-Werke AG" aquired the "Dixi-Werke" from the "Gothaer Waggonfabrik AG" (Gotha Railway Car Factory). The subsidiary Dixi Works had been founded in 1896 at Eisenach, Thuringia, and had originally been called "Fahrzeugfabrik Eisenach".
At first, military vehicles and bicycles were built by this concern, but only two years later, in 1898, automobiles were already being constructed there under license from the French firm of Decauville, these machines bearing the name of "Wartburg". From this point onwards a series of remarkable designs saw the light of day, with which the company actively engaged in motoring sport. Following the First World War the "Gothaer Waggonfabrik AG" acquired the concern in Eisenach and changed its name to "Dixi-Werke", making it into a subsidiary of the mother company. Automobile production continued, as did the participation in sports events.
When, a few years later, the "Gothaer Waggonfabrik" was bought up by the Schapiro concern of Berlin, the Dixi works also became a part of that industrial group which already controlled two other automobile
and motorcycle factories: Cyclon and NSU. Schapiro, who wanted to build a rational automobile
equated to the lean times of the Germany of that era, decided to produce a small, reasonably priced car in large numbers. To this end he acquired the contract to built the English Austin 7
under license, towards the end of 1927. Going into prooduction at Eisenach during January, 1928, the car was known as the Dixi on the German market, and was built in two versions: as a two-seater roadster and as an open, 4-seater touring car. Its 748 cc engine delivered 15 bhp and gave it a top speed of approximately 45 mph.
BMW took over the Dixi works at Eisenach on the 14th November, 1928, and continued producing the Dixi, but under a new designation as BMW 3/15. At that time, the roadster and touring car versions cost from 2,175 to 2,675 Reichssmarks and they remained in prooduction until 1932, a total of 25,365 units being built in all. In its final version the car attained a top speed of 53 mph and, as the Wartburg Sport, delivered 18 bhp and attained a speed of 65 mph.
Of the sports model, 400 units were produced. The year 1932 saw a further developed version which was built as a saloon and known as the BMW AM 4. The engine's 56 mm bore remained as previously but its 76 mm stroke was enlarged to 80 mm, with the resulting increase in displacement yielding a greater power output of 20 bhp. A single carburettor fed the 795 cc engine and gave the compact little car a top speed of 55 mph. A 3-speed transmission was employed and the car was exceedingly well built The BMW-Dixi and its successsor did well in competition. For example, during the first 10,000 kilometre reliability run through Europe, which had the Avus race track in Berlin as its end point, four BMW-Dixi 3/15s won the team prize. The year was 1931.
In 1933 BMW laid the cornerstone for an entirely new series of car, having 6-cylinder engines, and through the development of these powerplants a number of cars were produced which would establish the international reputation BMW had attained in the field of aviation and motor-cycling
or the automotive scene as well. The first of the series was the Type 303, which the 1,175 cc in-line six produced 30 bhp from bore and stroke dimensions of 56 x 80 mm. A 4-cylinder machine, the Type 309 followed in 1934, its 875cc displacement yielding 22 bhp.
That same year saw the introduction of the BMW Type 315 which was a further development of the 6er concept. With a 58 mm bore, 94 mm stroke and twin carburettIrs the 1,475 cc powerplant devellped 34 bhp. The 315 was the first BMW to be equipped with a 4-speed transmission and it was produced as a compact 4-seater saloon. During an era in which luxury cars possessed excessively large dimensions, BMW built compact cars which utilized their interior space to advantage in comparison to the overall size, all the while maitaining good performance.
The 315 gave birth to one of the most beautiful automobiles in the 5-litre class at that time: the 315/1 Touring Sport. Appearing in 1934 it was an immediate hit, being powered by the 315 engine with hemispherical combustion chambers and having three carburettors. Its 40 bhp was good for a top speed of 77 mph, and in 1934 a factory team won the 2000-kilometre German reliability trials as well as the International Alpine Trials with the 315/1 Touring Sport. Many other victories were to follow. The car cost 5,200 Reichsmarks at the time. Since the automobile
licensing fees in Germany were equated to engine displacement, the 1.5-litre chassis was also offered as a lighter, less-luxurious version powered by the 22 bhp, 875cc 4-cylinder engine.
Also dating from 1928 is the BMW Wartburg, the sports roadster version of the Dixi touring car. Its four cylinder powerplant of less than 800cc displacement developed a sprightly 22 bhp...
In order to attain a similar level of riding comfort as the more-refined 6-cylinder machines possessed the 4-cylinder unit was rubber-mounted on only two points of the chassis. BMW designated this type of mounting as "Schwebemotor
" (suspended engine). The entire 1934 production series possessed torsionally rigid, tubular-steel chassis with transverse supports, synchronized transmissions and a newly developed rack-and-pinion steering
unit. In 1935, licensing fees were abolished in Germany, this policy naturally giving the constructors much greater leeway. BMW made good use of the increased possibilities and introduced the Types 319 and 319/1 in rapid succession, both being powered by the standard 6-cylinder, inline engine measuring 65 x 96 m and stroke for a displaceeent of 1,875 cc.
The 319 engine was fed by twin carburettors and was rated at 45 bhp, while the 319/1 utilized three carburettors and delivered 55 bhp. This was the sports car, its exterior being similar to that of the 1.5-litre, 40 bhp 315/1 Touring Sport. In this manner BMW's 1935 line consisted of one body which was offered with three different powerplants: the 875cc unit delivering 22 bhp; the 1.5-litre engine yielding 34 bhp; and the 1.9-litre which developed 45 bhp, in addition to which the lovely little sports roadster was offered either with the 40 or the 55 bhp engine. BMW also produuced the 325 4-wheel-drive, cross-country vehicle for the German Wehrmacht.
The BMW passenger cars were developed step-by-step. Starting at the bottom and working upwards was a sound policy and, combined with a very high quality of construcction, systematically led to a group of customers loyal to the marque. However, BMW didn't remain idle. In 1936 another step upwards was undertaken and a brand-new model was introduced which, nevertheless, made use of the already well tried drive-train components and other mechanical parts previously used. The body of the newly designated 326 differed from the previous models and the car moved up into a more luxurious category, but the engine was based on the well-proven 6-cylinder series and displaced 1,975 cc.
Built from 1934 until 1937, this sports roadster was a direct development of the 315/1, with a 2-litre 6-cylinder engine in place of hte 1.5 litre unit. Developed power was 55 bhp...
With twin carburettors, 50 bhp was developed and a 4-speed transmission was utilized. With this new model the typical BMW grille, which stamps the cars of the marque to this day, was also introduced. Besides the modern 6-cylinder engine, the 326 possessed a number of interesting details, such as a torsion-bar rear suspension, a fully synchronized, 4-speed transmission with the two lower gears incorporating a freeewheel mechanism, and a swing axle at the front whose upper portion also provided the function of shock absobers. This model was built in a less luxurious version as well and offered at a lower price, known as the Type 320/321. It had only two doors and its engine differed from the 326's in that it was fed by only one carburettor, the power output amounting to 45 bhp.
The model that followed was the highpoint of BMW's prewar automobiles, a machine which demonstrated not only an extraordinary standard of technical innovation, but one which possessed starting lines in its body design and a high performance which was amply demonstrated in countless racing victories: the 328
. Once again, the 328 wasn't really an all-new design as its basis was derived from the sports cars of the 6-cylinder series: the 315/1 and the 319/1, as well as from the 326. At first, the 327 was derived from the 326, this modified type being built either as a sports cabriolet or as a coupe, both body variations possessing exceptionally beautiful lines. The 1,975cc engine deliverred 55 bhp. Then, in the 1936 Eifelrennen, a new BMW sports car was entered in the class of unsupercharged cars up to 2-litres displacement, the driver being the already well-known record holder Ernst Henne, the machine - the 328. To quote a contemporary race report, "High spirits at the Nurburgring
as the racing cars in the category up to 1.5-litres' displacement, and along with them, the sports cars, are pushed to the starting line.
The BMW AM 4 saloon was developed from the Dixi. Its stroke was enlarged to 80mm with a resultant increase in capacity to 795cc and a power output of 20 bhp. This particular car was the winner of the Concours d' Elegance at Baden-Baden, held in 1932 ...
The big question among the press and the technical personnel is "Will the English or the Italians lead the 1.5-litre cateegory? How will the German sports cars finish?" The field moved off, the racing cars first, the sports cars following - almost silently compared to the racing cars.
Two drivers led their respective classes far ahead of all the rest: Trossi with the Maserati racing car and Henne with the new BMW sports car. They crossed the finish line-unchallenged!" Ernst Henne won this Eifelrennen in 1936 at an average speed of 63.0 mph over a distance of 70.82 miles, taking the flag ahead of Paul Schweder who drove his Adler to an average race speed of 60.2 mph.
The 328 utilized the 326's cylinder block, but instead of the stock cast-iron head, a light-alloy casting was employed, having inclined valves
actuated via pushrods and rocker arms by a low-mounted camshaft.
The intake valves
diameter was much larger than that of the exhaust
valves, the former being directly actuated by the pushrods, while the exhaust
valves were opened indirectly, their pushrods being positioned at an angle 90° to the cylinder axis, the mechanism being rather unorthodox but practical.
The camshaft timing was accomplished by a duplex chain. Much care was taken in the design of the intake manifold which possessed short, vertical intakes and was fed by three vertical Solex carburettors employing a special mixture-control jet for ease of starting and having large, well oiled air cleaners.
In the Ulster TT of 1936 the 80 horsepower 328 captured the first three places as well as the team prize; a remarkable performance...
The crankshaft ran in four plain, white-metal bearings. With a bore of 66 mm and a stroke of 96 mm, the engine was of the long-stroke variety and its displacement amounted to 1,971 cc. In its standard version, with a 7.6:1 compression ratio, 80 bhp was produced at 4,700 rpm, while the factory-quoted running speed (actually called "Arbeitsdrehzahl
", which means "working" crankshaft speed) was listed as 4,000 rpm.
This reference to a running speed regarding crankshaft revolutions was an interesting point, as the car could be driven constantly at a speed of 135 km/h, which equalled 83 mph, on the newly constructed German Autobahnen, the modern system of express highways linking the country's major cities. The 328's top speed amounted to 93 mph.
In its modified form, used for competition, the performance was naturally even greater. An outstanding feature of this technically well-conceived automobile
with its beautifully shaped and proportioned body lines, was the fact that it didn't serve just as a competition sports car but also found use as a comfortable, 2-seater touring roadster which enabled very high average speeds to be attained on trips.
Winner of the 2-litre sports-car category in the race in the Viennese hills on the 11th June, 1939, was Dr. Werneck of Garmisch...
With regard to the chassis, the 328's rear suspension consisted of half-eliptic leaf springs and a solid axle with hardened, spiral-bevel differential gearsets. At the front there was a parallelogram swing axle having a transverse leaf-spring as its upper element and wish-bones for the lower portion, with shock absorbers being mountted on them.
The frame was built up of tubular steel having a 90 mm diameter and possessed three box-section, transverse supports, the whole being electrically welded. Rack-and-pinion steering
was employed, with the rack having obliquely cut gear teeth. Furthermore, the chassis was lubricated via a centrally located, one-shot pressure system having 17 lubriication points, with engine oil being utilized. Naturally, the car was also equipped with an oil-cooler which was placed in front of the radiator
blind, the oil-flow being selflated.
The pressed steel wheels were of the centrally mounted, knock-off type and used tyres
of 5.25 x 16 dimensions. Four self-adjusting, hydraulically actuated brakes
were employed, each drum having a diameter of 11 inches. The car's instrumentation was very complete and naturally included a large tachometer. With water, oil and fuel on board, the kerb weight came to 1,826 pounds.
Many famous drivers and racing events are to be found among the 328's laurels, such as Prince Schaumburg-Lippe-Count Lurani
, winners in the 2-litre class of the 1938 Mille Miglia
, as well as the 24-hours of Spa-Francorchamps; where the BMW 328 was the class winner of sports cars up to 2-litres displacement in the King's Cup.
Huscke von Hanstein drives a 328 with characteristic energy in a 1939 sports car race in the Schotten circuit near Frankfurt. Note the sinister emblem behind the front guard...
In 1939 the car won the 2-litre class at Le Mans and in 1940 the team of Huschke von Hanstein and Walter Baumer drove it to victory in the Grand Prix
of Brescia, which replaced the Mille Miglia
that season, being run over a closed circuit for a distance of 1000 kilometres. One could continue enumerating the many wins which the car has to its credit in many different countries, and overseas as well.
The BMW 328 set the pace in the sports car events of that era and, besides the previously mentioned pilots, such famous luminaries as Prince Bira, Piet Nortier, Ernst Henne, Roese, Richter, Dr. Werneck and many others sat behind the wheel of this remarkable machine.
The racing victories created a great international interest for the car and the British firm, Bristol, acquired the license to build it. In its Mille Miglia
version, the engine developed 100 bhp and with streamlined, light-alloy spider and coupe bodies the 328 attained a speed of 125 mph.
The Type 327/28, which was offered either as a sports cabriolet of sports coupe, could have the 80 bhp engine optionally installed in place of the 55 bhp unit. Its price with the more powerful version of the 6-cylinder engine amounted to 8,100 Reichsmarks. The prewar BMW programme was rounded out by the Type 335, whose 6-cylinder, twin-carburettor engine had bore and stroke dimensions of 82 mm x 110 mm for a swept volume of 3,485 cc from which 90 bhp was produced. The car's body was similar, in concept, to that of the 326, but its headlamps were positioned in the front wings as on the 327/28 series. Maximum speed was 90 mph and its highway cruising speed, which was well above par for that era, amounted to 84 mph.