Innovative, efficient drivetrains heralded the beginning of automotive history. The single-cylinder engine for which Gottlieb Daimler applied for a patent on 3 April 1885, 135 years ago, was a classic example of a spark that ignited interest and action in every respect. Due to its overall appearance, the novel combustion engine was nicknamed the “grandfather clock”. It was compact, lightweight and was the first high-speed petrol engine to develop 0.37 kW (0.5 hp) at 700 rpm from a displacement of 264 cubic centimetres. A curved-groove control system operated the exhaust valve via a disc mounted on the crankshaft and a transmission rod.
In the same year, Daimler used the “grandfather clock” engine to build the “riding carriage”, the first motorcycle in the world. In this way, the inventor was able to prove that his idea for individual mobility was feasible using a compact drive unit.
Independently of Daimler, Carl Benz in Mannheim developed his three-wheeled patent motor car with a combustion engine, which he had also designed himself, and applied for a patent for it in early 1886. This was the first motor car the world had seen. In the summer of the same year, Daimler followed suit: he fitted a more powerful version of the “grandfather clock” with an engine capacity of 462 cubic centimetres and an output of 0.8 kW (1.1 hp) in a carriage designed to be horse-drawn, thus creating the first four-wheeled motor car.
Ever since these premieres, the will to innovate in drive technology has been the hallmark of the company’s development work. To this day, each new engine generation is more powerful and more efficient than the ones before. The same applies today to the development of electric motors in cars: as with their predecessors in the first vehicles made by Daimler and Benz, the objective is to extract an ideal amount of power from the available energy supply.
1890: The world’s first four-cylinder petrol engine
In 2020, two other important engine developments are celebrating their anniversaries. In the spring of 1890, 130 years ago, Wilhelm Maybach, the gifted designer at Gottlieb Daimler’s side, built the first four-cylinder petrol engine, and thus created a standard form of combustion engine that is still relevant today. The engine weighed 453 kilograms, had a displacement of six litres and produced 9 kW (12.3 hp) at 390 rpm. The first of these was delivered to New York as a marine engine on 21 August 1890.
Just ten days later, a second and smaller four-cylinder marine engine was dispatched. This one had a displacement of 2.4 litres and developed 4 kW (5.9 hp) at 620 rpm. Yet another figure underlined Maybach’s important contribution to the further development of engine technology: this engine weighed a mere 153 kilograms – which was only about a tenth of the weight of contemporary stationary engines. Moreover, those contemporary engines only produced a third of the power, and besides, they had one key disadvantage: they were not mobile.
Daimler four-cylinder engines were also pioneering in terms of their technical construction. Maybach replaced Daimler’s curved-groove control system with a camshaft that actuated a set of overhead exhaust valves, which was an essential requirement for efficient vapour management in in-line engines. Water jackets surrounded the engine cylinders to provide an effective cooling system. Another important innovation was the four-throw crankshaft, also a basic concept still in use today.
The technological advances achieved and the groundbreaking products that they made possible were evidently the encouragement Gottlieb Daimler needed to put his far-reaching entrepreneurial ideas into practice. On 28 November 1890, also 130 years ago, was the official founding of Daimler-Motoren-Gesellschaft.
1910: Four-valve in-line engine used in the Benz 100 PS “Prince Heinrich car”
Twenty years later, another technical milestone was provided by competitor Benz & Cie. In 1910, 110 years ago, the touring cars designed for the Prince Heinrich Tour made use of the innovative four-valve technology: their four-cylinder in-line engines had two inlet and two exhaust valves per combustion chamber. The 7.3 litre engine developed 74 kW (100 hp) at 2,050 rpm, while the smaller 5.7-litre engine produced 59 kW (80 hp). Two camshafts operated the tappets and rocker arms through an overhead valve design and the valves were arranged at an angle in the combustion chamber.
This unusual engine was designed under the supervision of Dr Hans Nibel. The rapid progress witnessed in engine development can be illustrated by a brief flashback to the above-mentioned first four-cylinder marine engine produced by Daimler: in 1890, 9 kW (12.3 hp) at 390 rpm from a six-litre engine was a considerable feat of engineering. But twenty years later, the four-valve high-performance engine produced by Benz defined a completely different set of new standards.
The best of the six 100-horsepower and the four 80-horsepower racing cars entered by Benz & Cie. in the third Prince Heinrich Tour (2 to 8 June 1890) over a distance of 1,944.6 kilometres crossed the finishing line with Fritz Erle at the wheel in fifth place in a field of 127 cars. In that race, he achieved a top speed of 133.6 km/h in the Genthin speed test, which meant that the new engine had most effectively demonstrated its performance capabilities.
In 1911, the Laboratory for Motor Vehicles at the Royal Institute of Technology in Berlin subjected the 7.3-litre racing car to a series of thorough tests. The thirty-three-page report confirmed the four-valve engine’s output of no less than 87 kW (118 hp) at 2,050 rpm and, on the chassis dynamometer, the vehicle reached a top speed of 134 km/h.
Four years later, this four-valve technology was also taken up by Daimler-Motoren-Gesellschaft and Paul Daimler used this advanced technology successfully in the Grand Prix racing car for 1914. To this day, four-valve four-cylinder engines are one of the most important types of combustion engines.
Source: Mercedes-Benz Classic