As the story goes, driver Karl Kling failed to notice a group of vultures at the side of the road during the 1952 Carrera Pan Americana race. As they dispersed, one crashed through the passenger side windshield knocking co-driver Hans Klenk momentarily unconscious. As he recovered, he ordered Kling to maintain full speed, and only stopped to clean himself up at the next stop, where bars were welded in front of the windshield to protect against a repeat occurrence. They went on to win the race, averaging 102mph, and the incredible story has been told many times. Behind the famous human story though, is the story of the W194 itself.
It represented a return to racing for Mercedes, but without tremendous resources, they focused on weight and reliability as areas where they could gain an advantage in sports car racing. A new engine was not on the menu at the time, so it was powered by a single overhead cam 3.0 liter straight 6 cylinder engine which came from the relatively sedentary Adenaur sedan (W189). Chief engineer Rudolf Uhlenhaut equipped the car with a tubular aluminum space frame, pretty advanced at the time, which weighed around 180lbs. However, the frame made conventional doors impossible, and so very short versions of the iconic gullwing doors were developed to get around that obstacle. Clear plastic was used instead of glass for all of the windows. Holes were drilled in the shock and spring supports, and finned aluminum (bonded to steel liner) brake drums were used to further reduce weight and dissipate heat. 15” wheels were chosen over 16” wheels to reduce unsprung weight. The W194 became the first machine to gain the coveted SL designation for super lightweight.
The car had independent suspension at all four corners, although the swing axle design in the rear made it a challenge on rough terrain. Another obstacle was the desired low hood line. This was overcome by slanting the engine, using a dry sump arrangement, and by creating a slanted head to create greater clearance for the bank of triple solex carbs. The finished engine produced 175hp, which was not a lot until you put it in a vehicle weighing 2500lbs total. The engine was tuned/detuned depending on race objectives, and the Pan Americana car was actually 3.1 liters. The gearbox was a fully synchromeshed 4 speed, with an oil circulation pump to help deal with the additional stresses. Trim was avoided in order to gain aerodynamic efficiency. Only 10 W194s were built, although technically, an 11th car was created with early Bosch fuel injection.
The results were impressive. 2nd and 4th in the Mille Miglia, a sweep of the podium at the Bern sports car race, a one-two at Le Mans (almost a 1-2-3), one-two-three-four at the Nurburgring, and a one-two in the Carrera Pan Americana. All of this just in 1952 ! Mercedes was officially back as a top tier competitor in international racing, and the entire brand gained great benefit. This did not escape the attention of famous New York importer, Max Hoffman, who convinced Mercedes to build a street version. This of course turned out to be the more well-known Mercedes 300SL Gullwing.