Mercedes-Benz M194 engine

The M194 is based on the M186 engine from the then-new W186 300^[1], exactly speaking on the M188 variant in the two-door W188 300S which had three Solex carburetors and 150 hp rather than two and only 115 hp in the limousine.

In any case it is a four-stroke engine six cylinder in line with two valves per cylinder.^[2] The engine is titled 50 degrees to the left in order to reduce the height of the hood. It uses a dry sump lubrication system instead of an oil pan and reservoir.^[3] It is also mounted behind the front axle for better weight distribution.^[4] Only 10 M194 engines were made for the W194 300SL racer; the first three cars had around 170 hp (127 kW), while the remaining seven had around 180 hp (134 kW).^[5]

For the Nürburgring sprint race event that supported the 1952 German Grand Prix, which did not favour endurance over power, Mercedes had announced a surprise.^[6] One car was fitted with the M197 engine version that had a blower, which was permitted in the "S 5000-8000cc" class, with the supercharged 3 litre treated as 6 litre. This "300SL K" had a bulge^[7] on the left side of the hood for the additional Kompressor, and was only used in practice, by Karl Kling. Being driven at a GP race weekend, it was the last Mercedes-Benz supercharged Grand Prix racing engine. The normal cars won 1-2-3-4 anyway.