Repsol YPF

The four-stroke cycle
In 1862 the constant volume cycle was enunciated by Beau de Rochar with the name four-stroke cycle.

The Otto cycle
Subsequently the German inventor Otto applied it to a thermal motor giving it the name Otto cycle.
If historically speaking Carl Benz has been considered as being the father of cars, as in 1885 he was the first to manufacture a four-stroke engine ignited by spark plugs, one has to go back to the year 1860 in order to find the first experiments on internal combustion engines. The first predecessor to Carl Benz motor was created by a Belgian with a fertile imagination whose name was Etienne Lenoir, who constructed his first practical model twenty five years before Benz, and who at that moment in time open the gates to evolution and established a series of technical principles which remained untouched until a few years ago. The first time that the four-stroke cycle was used with success was in 1876, in an engine manufactured by a German engineer, Count Nicholas Otto.

Compression ignition engine
In 1895, Rudolf Diesel presented his invention for the first time to the public. A compression ignition engine. In comparison with the already proven Otto explosion engine, this engine has the advantage of consuming much less and of being able to run on relatively cheap fuel, also being able to reach higher speed. Diesels invention soon became widely used and no longer faced competition in the field of naval and stationary engines. Nevertheless, the diesel engine had the great inconvience of it being impossible to reach elevated revolution regimes. But as the diesel engine became more and more widespread and more and more people discovered the advantages the system offered, more people started to demand a small and fast autoignition engine. The major obstacle for the diesel engine is the feeding of fuel. The insufflation method applied at the start with which the fuel is blown into the combustion chamber by means of compressed air, did not allow the number of revolutions to increase adequately. Apart from that, the air pump demanded a complex installation, which made it impossible to substantially reduce the size and weight of the engines.

Fuel injection system for diesel engines
At the end of 1922, Robert Bosch decided to develop an injection system for diesel engines. The technical conditions were favourable: He already had experience with combustion engines; production technologies has reached a high level of development and, above all, acquired knowledge could be applied in the manufacturing of lubricating pumps. Robert Bosch and his team worked tirelessly on this new mission. By the start of 1923 a dozen different fuel injection pumps had been thought up of, and by mid 1923 the first tests were carried out on the engine. The world of technology started to count more and more on the appearance of the fuel injection pump, from which a new drive in the manufacturing of diesel engines was hoped for. At last, in the summer of 1925, the last touches to the definite fuel injectio pump project were made and, in 1927, the first serial produced pumps left the factory. The fuel injection pump developed by Bosch gave the engine invented by Rudolf Diesel the desired speed, in the process providing it with unforeseen success. The diesel engine start to conquer more and more in fields of application, above all in the car sector.