BMW 328
In the mid-1930s, BMW quietly developed a sports car that was soon to attract a lot of attention. It brought BMW top placings in international racing history – the 328 Roadster.
The 315/1 and 319/1 sports cars had already put BMW among the leading manufacturers of automobiles that were also successful in racing competitions. However, the competition was continually supplying models of increasing power, and the 55 b.h.p. of the 319/1 top model to date was soon unable to keep ahead of the game. On the other hand, in 1935 BMW had only been in the automobile business for seven years and had only been constructing automobiles to its own designs for the past four years. Since the small racing department only had limited resources available, it was necessary to draw on proven technology for a new model.
A more lightweight and more stable tubular frame with box cross members formed the mounting for the front-wheel suspension with lower transverse links and an upper transverse spring. The rigid rear axle had semi-elliptical longitudinal leaf springs. A further increase in power of the 1.9 litre engine with low-mounted camshaft could only be achieved using a new cylinder head with V-shaped overhead valves, but the costs for a completely new design of engine block and cylinder head would have exceeded the budget. The engineers therefore made use of a trick. They simply designed a new head using an aluminium alloy, while the valve timing was controlled from the side camshaft via a reversing lever on the intake side and transverse push rods.
The result was 80 b.h.p., more than adequate to generate a sensation in the important two-litre class. The rear of the bodywork for the new BMW 328 Roadster bore strong similarities to the Type 319/1, but it had a significantly longer bonnet held down by two leather straps, and headlights integrated in the front. Initially, this model was only used for racing from mid-1936 and volume production started up in spring 1937. This sports car quickly developed into a racing legend. There was hardly a race in the late 1930s where one of the top slots wasn’t taken by the BMW 328. Special racing versions with special Superleggera ultralight bodies and engines with around 135 b.h.p. won their class at Le Mans and in the Mille Miglia.
Type of body:The BMW 328 was sold only as a roadster in standard form, though 59 chassis were also supplied for special bodywork to be fitted.
Special bodies: Sports convertibles based on the BMW 328, but more luxurious than the series cars, were manufactured among others by Drauz, Weinberger, Gläser, Wendler (also with a hardtop) and the Vereinigte Werkstätten. In addition, two BMW 328 cars with a closed, streamlined body were manufactured at Wendler in Reutlingen.
General data
Construction………………………….1936 – 1940
Number produce …………………….464
Price……………………………………RM 7.400
Specifications
Motorart………………………………6-cylinder in-line engine
capacity in ccm……………………..1971
Rated power………………………….80 PS bei 4500 U / min
Maximum speed in km / h…………..155 (96 mph)
Dimensions (L/H/B) in mm…………..3900x1550x1400
Weight in kg………………………….780
- Engine
Motortype…..6-cylinder in-line engine
Bore x Stroke (mm)…..66 x 96
Capacity…..1971 ccm
Performance…..80 bhp at 4500 rpm
Compression…..1 : 7.5
Valves…..Overhead, hemispherical combustion chamber, operated by pushrods and rockers, camshaft in crankcase.
Carburetion system…..3 Solex 30 JF downdraught carburettors - Powermode
Clutch…..Single dry plate clutch
Transmission…..Four-speed, central shift, synchromesh on 3rd and 4th gear
Gearbox ratios…..ZF gearbox: 1: 3.63 / 1: 2.07 / 1: 1.50 / 1: 1 Hurth gearbox: 1: 3.07 / 1: 1.82 / 1: 1.25 / 1: 1.
Reverse gear….. ZF gearbox: 1 : 4.27 – Hurth gearbox: 1 : 3.07.
Drive transmission…..1 : 3.88 with ZF gearbox or 1 : 3.0 with Hurth gearbox - Electric system
Generator…..90 or 130 W
Battery…..6 V 75 Ah
Spark plugs…..Bosch W 240 T 1 - Suspension
Body/chassis…..Tube frames with box-section cross members
Front-wheel suspension…..1 upper transverse spring, lower transverse link with integrated hydraulic lever-type shock absorbers.
Rear-wheel suspension…..Rigid axle, half-elliptic springs with hydraulic lever-type shock absorbers
Wheel rims3.25 x 16 well-base rim or 3.50 D x 16
Tyres…..5.25 x 16 or 5.50 x 16
Front brakes…..Hydraulic drum brakes
Front brake diameter (mm)…..280
Rear brakes…..Hydraulic drum brakes
Rear brake diameter (mm…..)280 - Measures and weight
Length x Width x Height (mm)…..3900 x 1550 x 1400
Wheel base (mm)…..2400
Front track (mm)…..1153
Rear track (mm)…..1220
Empty weight (kg)…..780
Permissible total weight (kg)…..1220
Fuel consumption (l/100 km)…..14.5
