One thing that this approx. 1,5 ton engine, developed in 1876, and producing 4 hp (3 hp*) made quite clear, is that it was not intended for the installation in a vehicle. Rather, it was used in factories to drive the machines through sometimes long belts and shafts (transmissions). At the time of it's production start in 1864, the Gas Engine Factory Deutz AG (which gets it's name from a Cologne suburb) and which later became simply the Deutz AG, was the oldest production plant producing combustion engines in the world.

In 1860, Nikolaus August Otto was a travelling salesman for a Cologne company selling groceries and colonial wares. Although not an engineer, he was very much interested in the developement work of Jean Joseph Étienne Lenoir. Using a copy of the Lenoir atmospheric engine, together with a mechanic, he developed a four-cylinder with a compression stroke, which, in the course of events, was known as the four-stroke, or Otto engine. He was granted patents by various German states, not however, by the state of Prussia. After the engine already functioned in it's first tests, he gave up his job so that he could tinker with his engine all the time.

The important thing about this new invention, was the compression stroke. This however, made the combustion so strong that an even delivery of the torque and a regulated engine running was unthinkable. It also endangered the mechanics of the engine itself. By using a leaner mixture this became better, however, unacceptable misfiring was the result. When almost all of his financial means were used up, he got to know the energetic, successful and wealthy sugar industry engineer, Eugen Langen, with whom in 1864 he founded the 'N. A. Otto & Cie' in the Servasgasse on the left bank of the river Rhine in Cologne.

Instead of the four-stroke-, in the next three years, an improved version of the atmospheric gas engine was developed. The world exhibition in Paris turned out to be the crucial experience as far as the development of the company was concerned. The new “old” engine was not only rewarded with a gold medal (Napoleon III.), it proved itself in tests, to also be far superior to the Lenoir engine. Production und sales of this engine ensured the company, which as of 1872, was called the 'Gas Engine Factory Deutz Corporation', success and income for at least 10 years. In the course of the expanding, further qualified people, who were rare in this specialised area, came into the company.

With the war against France over in 1871, the increasing demand, the relocation to the other side of the Rhine, which was linked with the expansion of the company, new production methods were to be introduced. Thus, in 1872 Gottlieb Daimler joined the company as the technical director and was followed by Wilhelm Maybach as the construction director. Daimler was already involved at the time with the planning of the new factory. He would be play an important part in the successful and efficient manufacturing of the engines.

For many years the two families, Otto and Daimler, lived in the same house. Both principle characters had had very different concepts of life behind them. On the one hand, the worldly and eloquent engineer Daimler, who relied determinedly on his enormous experience, and on the other hand, the rather reserved and pensive self taught tinkerer, Otto, who followed an idea unyieldingly and tenaciously, but seldom went beyond the borders of Cologne. Ultimately, this could not go off well, however, more about this later. The fact is, that Daimler and very much also Maybach, played a decisive role in the extending of the patents and the sales success of the atmospheric gas engine.

The question of who was responsible for which part of the development of the four-stroke engine, will probably never really be cleared up. The most important sources consider it likely that the ideas of Nikolaus Otto were originally responsible for the new engine. Actually, it was not only all about the compression stroke, but it's teamwork with the charging and fuel-air ratio. It is extensively described how Otto came upon the deciding idea. Apparently the idea came from simple observations, and not from any existing documentation. In any event, the solution was, a sort of layer charging, a lean mixture beforehand and a rich mixture afterwards, that finally, after 14 years, brought the engine to the desired saleability.

It was high time for the new engine because the development possibilities of the atmospheric gas engine with its 1,5 kW (2 HP) and a construction height of 3 meters, and 2,2 kW (3 HP) with a ceiling of 4 meters because of the extending gear-rod, were exhausted. It never got as far as a possible multi-cylinder engine. The new engine was developed, performance-wise, away from the old one and was the star of the world exhibition in 1878, once again in Paris. Daimler also took part in the development of a lighter variation. In Cologne-Deutz, engines for boats, on the basis of petroleum as fuel, were also being considered. There were tests to substutute the glow- with the electric ignition.

Also, and particularly through Gottlieb Daimler's work, the company showed a furious development. Nevertheless, it repeatedly came to differences of opinion with Otto and also Langen. After Daimler's vain trip to achieve a possible entry into Russia, he was given a stately compensation, although actually, he would not be allowed to work on the four-stroke for five years. Wilhelm Maybach apparently, was not even asked whether he would like to remain. Thus, he went into service with Daimler and proved furthermore, his talent as a designer

Otto considered his lifes work to be secure, however, he had to fight for a long time for his patents. After a short while, when he wanted to enforce the patents against so-called replicas, these were partly confirmed as being older than his own engine, although the products were introduced, they were, by no means, realised and successful in their manufacture. His patent was lifted in 1886. Perhaps the development step was just too big for one company alone to profit from. In 1936, a great honour was conferred on him posthumously, when the Association of German Engineers declared all engines working on the four-stroke principle (except Diesel!) to be Otto engines.

The stroke of 240 mm (300*) together with a bore of 155 mm (161*) resulted in a single/total displacement of 4,5 liters (6 liters*). The two different figures come about due to the fact that the original test engine was again modified before the, much later, serial production by Wilhelm Maybach. Despite the lower cubic capacity, due to the higher revving level of 240 RPMs, the performance was increased. The stroke of 240 mm (300*) together with a bore of 155 mm (161*) resulted in a single/total displacement of 4,5 liters (6 liters*). The varying figures come about by the fact that the original test engine was again modified before the, much later, serial production by Wilhelm Maybach. Despite the lower cubic capacity, due to the higher revving level of 240 RPMs, the performance was increased.

The above shown engine from 1895, which was still in operation till 1953, is of course, no longer quite original. Originally, he ignition was controlled by a sliding valve which opened the space for a gas flame at the deciding moment. Later, this method of ignition was replaced by a low-voltage magneto ignition. Bosch took over large parts of this unpatented invention, and returned the favour by turning over the implementation of the high-tension ignition to Deutz.

The engine was also no longer operated with illuminating gas but with petrol. In this case the fuel was really gasified, in contrast to the later, also called single carburettors. By the way, the expression that we still use today 'to give gas', came from the fact that the engines were originally fueled with city-gas, the performance was regulated by opening and closing the the gas-tap.

There will be noticed the long, quite massive designed shaft the first of all controls the opening to the ignition chamber. In addition, it drives the located in a large pot centrifugal governor, the when exceeding a maximum rotational speed displaces a cam on the shaft, and thus influences the control of the inlet.

The original engine was strictly stationary, because it was too large and was fueled by illuminating gas. The Servasgasse engines used so much of the gas when being started up in the morning, that the street-lights went out. For this reason, some atmospheric gas engines had a sort of bellows used for storage. With the current that they generated e.g., the cathedral in Cologne was lit up at it's inauguration in 1880. Only later would Daimler and Maybach develop a smaller petrol fueled engine. After 1885, through fueling with petrol, the operation of the large and heavy Deutz-engines was also possible, e.g., in mining locomotives.

In 1907, another, also well known contemporary, Ettore Bugatti, appeared at the Gas-Engine-Factory-Deutz-AG. The company was doing very well and he was accomodated befittingly. He was to have promoted the vehicle section, however, after two years, he failed. All together almost 50 cars were built. Bugatti would carry his construction ideas over into his own company, which he then founded. 11/11
*marks the data of the first test-engine