In 1969, the rotary engine was the longer term, and with its C 111 prototype, Mercedes-Benz aimed to showcase the potential of the compact, light-weight engine design.
On the time, each main automaker had licensed Felix Wankel’s rotary engine and plane engine maker Curtiss-Wright put in one in all its prototypes right into a 1965 Mustang hoping to curiosity Ford Motor Co. within the engine. Basic Motors designed its personal engine, which might have been used within the Corvette and American Motors designed its unorthodox Pacer household automotive with the expectation of shopping for rotary engines for it from GM.
On this surroundings, Mercedes sought to exhibit its technical prowess with a speedy sports activities prototype that includes a 280-horsepower three-rotor engine that might pace to 162 mph. The group progressed shortly, and Solely 5 months later C 111-II was fitted with a four-rotor Wankel engine with an output of 350 hp. With this engine, the C 111 might attain 186 mph and scoot to 60 mph in simply 4.8 seconds.
The engine wasn’t the one supply of enchancment. The C 111-II’s bodywork was improved when it comes to imaginative and prescient for the driving force in addition to aerodynamic effectivity, with a coefficient of drag of 0.325, which was glorious for the time.
However apart from Mazda, the world’s carmakers had little success producing sturdy rotary engines, because the three-sided rotors spinning inside them wanted seals at their apexes that served within the position of piston rings in a reciprocating engine to seal combustion gases within the combustion chamber. Mazda was the one automotive firm to achieve growing apex seals, so the others gave up.
That they had little motivation to good the engine as a result of, whereas it the design is highly effective and compact, it’s also thirsty and susceptible to creating extreme air pollution. The Seventies gas shortages and worth shock, together with more and more stringent emissions restrictions led Mercedes, together with many of the trade, to desert the rotary engine.
Along with Mazda, Suzuki and Norton made rotary-powered bikes for a couple of years, however even in that utility the place compact measurement, gentle weight, and energy are particularly fascinating, the rotary engine did not catch on.
In response to demand for gas effectivity, Mercedes pivoted to diesel energy for its manufacturing fashions and revamped the C-111 with a production-based diesel engine to showcase the engine’s efficiency potential.
The engine was the five-cylinder three-liter naturally aspirated diesel from the 240 D 3.0 and 300 D, with a Garret turbocharger and an intercooler added, boosting the engine’s output of 80 hp to 190 hp to energy the C 111-IID.
The automotive set information on the Nardo take a look at monitor in Italy on June 12, 1976. In whole, 16 new information have been set – these over 5,000 miles, 10,000 kilometers, and 10,000 miles. These have been absolute world information, unbiased of the kind of engine. The automotive averaged 158 mph.
In 1978, Mercedes was again, with narrowed and lengthened bodywork and the identify C 111-III. This one carried a 230-hp model of the engine and had a Cd worth of 0.183, the bottom ranking ever achieved as much as that point. The outcome this time was a median pace of greater than 186 mph and 15 miles per gallon at that pace. By comparability, a rotary-powered automotive would have had comparable gas consumption in around-town driving.
At present we will nonetheless admire the C 111’s magnificence and technical sophistication, so click on by way of the picture gallery for extra data.
