Mercedes-Benz W 165 (1939)

Aug 20, 2012
  • Specially designed for the Tripoli Grand Prix
  • Developed in a record time of just eight months
  • Double victory and thus mission accomplished
The Tripoli Grand Prix marked a notable exception among the Mercedes-Benz victories of 1939. The competition was not held according to the 3-litre formula dominated by the German racing cars, but according to the 1.5-litre category (voiturette formula), for which the Stuttgart team – up until then – did not have any entrants. With this trick, the Italian motor racing authorities responsible for organising the prestigious Tripoli Grand Prix in Libya – at that time an Italian colony – hoped to undermine the dominance of the Silver Arrows and ensure once and for all victory for the Italian cars. The Italians’ last win in this race had been back in 1934, since when the German cars had repeatedly triumphed on the Mellaha circuit: Caracciola had won in 1935 and Auto Union in 1936, while in 1937 and 1938 it had been taken by Hermann Lang at the wheel of the winning Mercedes-Benz.
Mercedes-Benz, however, was not to be so quickly deterred from competing in one of the most important races of the Grand Prix world of the 1930s. From when the new regulations were issued, in September 1938, the Stuttgart team proceeded to take less than eight months to develop a completely new racing car: the W 165. The key drawings were soon provided by engine specialist Albert Heess and chassis expert Max Wagner, so that the first vehicle was ready to be tested by Caracciola and Lang at Hockenheim as early as April 1939. It was therefore with considerable astonishment that the international racing world saw two Mercedes-Benz W 165 cars with a displacement of 1.5 litres appear in the list of contenders for the Gran Premio di Tripoli.
The new racing car bore a distinct similarity to the existing W 154 racing car but appeared, at first glance, to be a scaled-down version of the 3-litre racer. The struts of its oval tubular frame were made out of nickel-chrome-molybdenum steel, with the five cross-members supplemented by the rear engine bracket. The driver did not sit in the middle, but slightly to the right. With a full fuel tank the W 165 weighed just 905 kilograms. The engine too, even though it weighed just 166 kilograms, was clearly a close relation of the V12 engine from the W 154. It was a V8 engine with a displacement of 1493 cc, a V-angle of 90 degrees and with four overhead camshafts and 32 valves, with an almost identical arrangement and drive system to those in the Grand Prix model. The mixture was prepared by two Solex suction carburettors, with powerful support from two Roots blowers. Its output of 254 hp (187 kW) at 8000 rpm equated to a power-to-swept volume ratio of 170 hp (125 kW) – an absolute record figure. This power was tamed by large brake drums (360 millimetres in diameter), that almost filled the whole inside part of the spoked wheels. The engineers even allowed for the extreme temperatures to be expected in the host country – on race day the temperature on the track would be 52 degrees Celsius – by running the fuel pipes through tubular coolers.
The rest is racing history: the two Mercedes-Benz W 165s left their opponents no chance. Caracciola, in his shorter-ratio vehicle, completed the entire race without a break, while Hermann Lang – in line with Neubauer’s carefully devised tactics – made a brief pit stop to change tyres and won the Tripoli race in his longer-ratio vehicle (which thus had a higher maximum speed) almost a full lap ahead of his fellow Mercedes driver. A historic victory.
Mercedes-Benz W 165
Year of construction:
254 hp (187 kW)
Top speed:
272 km/h