This month we continue reprinting a series that first appeared in GEM in the March-April 1969 issue. Over the coming months, we will retrace engine history as presented by Carelton M. Mull. This segment originally appeared in the July/August 1969 issue of GEM.
Early inventors as Huyghens, Papin, Robert Street, Barnett, Samuel Brown and others, while testing versions of their engines, realized considerable accomplishment when they were able to get an engine to explode the fuel in a proper progression to create enough power to keep a flywheel turning. Under such circumstances, with crude machines, it was hardly possible to classify engines according to a type such as two or four cycle.
From all of these efforts, a light was dawning. In England, an engineer by the name of Dugald Clerk worked on an idea of one intake stroke and one power stroke on his engine by using the travel of the piston to uncover a port in the cylinder to exhaust the burned gases. His engine was built with an auxiliary cylinder used to compress air for scavenging.
When the power piston moved towards the end of the expansion stroke, it uncovered a port through which the exhaust gases pass; thus reducing the pressure in the main cylinder to that of the atmosphere. Pressure from the displacer cylinder was then admitted through a valve in the head, forcing out the burned gases and charging the combustion space for the next power stroke. This series of events within the cylinder is repeated in every revolution of the engine. The auxiliary or displacer cylinder with the intake valve arrangement made this a rather difficult engine to build. It was a definite type, and Dugald Clerk explained his engine as a two-cycle machine, establishing for the first time this fundamental design.
During the next decade, this two-cycle type was improved and simplified. Much experimentation and research has perfected the two-cycle as it is known today; as it is widely used in the smallest and largest gasoline and diesel engines on today's markets.
While Lenoir and Clerk were building engines, another French engineer, M. Beau de Rochas, 1862, was conducting experiments on the theory of the actual operating conditions inside the combustion space of a gas engine and on the matter of the firing sequence. He found a better operating system by utilizing one stroke of the piston to charge the cylinder with the explosive fuel, and the next stroke to compress the fuel mixture and then fire it at near top dead center using the next forward stroke for power, with the return stroke of the piston to exhaust the burned gases. Thus it was Rochas who was the inventor of the four-cycle internal combustion engine.
During the period from 1860 to 1875, there were a number of inventors at work improving the designs of Lenoir and Rochas.
Two men who contributed much in this respect to the development of reliable gas engines in the early stages of this industry in Europe were Nickolaus A. Otto and his partner Eugen Langen of Germany. They improved on the four-cycle design, and in 1878, Otto developed the first magneto ignition. They founded the N. A. Otto and Cie Company, and also the Gas Motoren Fabrick Deutz Company.
The output of their factories expanded and their engines were shipped to the countries of Europe and to the United States. During the years of 1878 to 1895, they sold over 45,000 engines.
The imports of the British, French and German engines into this country influenced our first inventors. The Otto Gas Engine Company was established in Philadelphia, Pennsylvania, where they manufactured vertical cylinder engines from 1 HP to 3 HP and horizontal engines from 2 HP to 120 HP. Many old textbooks describe these original Otto engines as having horizontal open and water-cooled cylinders bolted to a cast iron sub-base which also carried the main bearing journals. From bevel gears on the crank shaft, the lay shaft along the side of the engine, operated the slide intake valve as well as the governor.
Ignition was by a gas flame and timed by the movement of the slide valve mounted horizontally across the back of the cylinder head. The exhaust poppet valve was on the other side of the cylinder head and at right angles with the intake valve. For those who wish further details on this early engine, the patent is no. 194,047, dated August 13, 1877.
In 1875, the U.S. Patent Office issued the first three patents in this country on gas engines.
The first patent was issued to G. W. Daimler of Wurtenberg, Germany, by the United States as No. 168,623. This patent covered a very interesting design in stationary engines, because it seemed to be backwards from all other models so far developed. Both ends of the cylinder were open to the atmosphere. The power or working piston and connecting rod were water-cooled. Then, there was a loose piston at each end of the open cylinder and they were arranged to seal the cylinder when the explosion was about to take place. Ignition was by a gas flame. There was a crosshead at one end of the cylinder, with side arms connecting the crosshead to the flywheels at the other or opposite end of the engine. Anyone wishing to study this odd design may secure a copy of G. W. Daimler patent.
After years of development, Daimler built some of the world's finest automobiles. Associated with Messers. Benz, Maybach and Otto, Mr. Daimler built high speed automotive and airplane engines.
From these early factories came the simple small size gas engines. The horsepower ranged from a fraction to 5 HP for portable engines and up to approximately 100 HP for stationary units. The builders were experimenting in new fields for a wider application of their motors. In 1886, Mr. Benz and Daimler built one of the first vehicles to be powered by a gas engine, and it was successfully road tested as one of the first horseless carriages.
Outmoded transportation conveyances were much in need of improvement. Both land and water offered a great market for this new motive power that could be operated without a cumbersome steam boiler.
Daimler was one of the first inventors to. build marine engines, and in 1886 he was successful in putting an engine on a bicycle. He licensed Panhard and Levasser in France to build his engines. They built a three cylinder machine.
Argyle Co. and Renault, Friers and New Orleans Co. in France, were building an air-cooled engine at about this era, which was used in some of the small cars such as the Renault.