Mercedes-Benz Type S, 1927 - 1928
The Type S sports car (S for Sport) introduced in 1927 marked the beginning of a new era for the former Daimler-Motoren-Gesellschaft and Benz & Cie. companies, which had merged to form Daimler-Benz AG in June 1926. Drawing on numerous technical features of the successful Model K racing touring car from the year before, an automotive icon was created which, in its racing version and together with the evolution models developed from it, dominated international racing touring car and racing sports car competition until the early 1930s and helped the newly created Mercedes-Benz brand to achieve the highest reputation from the very beginning.
The new design took up exactly where the Model K had still lacked a sporty profile. The 3400 mm wheelbase of the predecessor was used, but the chassis design of the Type S was refined considerably. To achieve a low vehicle silhouette and a centre of gravity as low as possible and concentrated between the axles, the offsets on both longitudinal members of the pressed steel frame with its U-shaped profile were significantly reinforced on both the front and rear axles. This allowed a particularly low installation position for the voluminous six-cylinder supercharged engine, which was also moved back by 300 mm, making it a front-mid engine in today's terminology. The pointed radiator standing upright in the airstream was also made about a hand's width lower in order to keep the overall height low.
By the standards of the time, the open-top four-seater racing touring car, whose lightweight soft top was more of symbolic significance, had an extremely crouched, almost slender appearance. In fact, the engineers had succeeded in massively reducing the vehicle weight of the new model to 1900 kilograms compared to the Model K, its predecessor - despite the considerably enlarged engine.
The previous model's supercharged six-cylinder with an overhead camshaft driven by a vertical shaft had also been profoundly revised. At the heart of the measures aimed at significantly increasing engine performance was an increase in displacement to just under 6.8 litres. For this purpose, the bore was increased by 4 mm to 98 mm, while the stroke remained the same at 150 mm. In order to create the necessary space, major changes had to be made to the engine block, which was still made of the aluminium alloy silumin: it was converted from "dry" to "wet" cylinder liners, i.e. coming into direct contact with the cooling water, a state-of-the-art technology at the time that produced more efficient cooling and was less costly to manufacture, but degraded the rigidity of the engine block.
In addition, a camshaft with different timing as well as an increased valve lift provided a significantly increased output volume compared to the original 6.2-litre engine. The unusually designed dual ignition was retained, in which one spark plug of each cylinder was supplied with power by a high-voltage magneto ignition and one by battery ignition.
The Daimler-Benz engineers also improved the mixture formation. Instead of one Mercedes updraft carburettor, two were now used, which in turn were pressure-tight and converted the charge air compressed by the Roots blower into an ignitable mixture.
The set goal of equipping the Mercedes-Benz Type S with superior engine performance was convincingly achieved thanks to these diverse measures. The six-cylinder engine was available in two performance levels: while 120 hp/88 kW without compressor and 180 hp/132 kW with compressor were stated for the tame version, which was intended more for road use, the sports engine with a compression ratio increased from 4.7:1 to 5.5:1, which was used in competition vehicles, had a peak output of 170 hp/125 kW without compressor and 225 hp/165 kW with compressor.
Right from the first start, the racing version of the Type S driven by the young talent Rudolf Caracciola offered a taste of what was to continue into the early and, with further evolutionary stages of the basic model, even into the late 1930s: the almost total dominance of the W 06 series in the corresponding touring car and racing touring car categories in flat races and hillclimbs. Caracciola drove a Type S to victory with an average speed of 101.1 km/h in the inaugural race of the Nürburgring on 19 June 1927 - also the racing début of the new model. Second place went to Adolf Rosenberger, also in a Type S, and third place to the private driver von Mosch in a Model K. In addition to the two talents Caracciola and Rosenberger, who were in the early stages of their careers, the veterans Otto Merz, Willy Walb, Christian Werner and Ernst-Günther von Wentzel-Mosau, among others, achieved numerous victories and top placings with the Type S by the end of the 1928 motor racing season. Domestic and foreign private drivers continued this success story unbroken until the end of 1931.
After a total of 146 units produced, chassis production for the Type S ended in September 1928. As successors, the types SS and SSK had already appeared three months earlier with spectacular successes.