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 Carlton M. Mull. This segment originally appeared in the May/June 1969 issue of GEM.
In the first installment about the origination of your hobby, it was stated that man's imagination led to experiments and inventions of the internal combustion engine; and how Thomas Newcomen's improved steam engine replaced horses to operate the mine pumps in collieries of England. Also how James Watt further perfected the open end vertical steam cylinder.
Along in the early part of the nineteenth century, there were many inventors working on the idea of producing an engine that would not require a cumbersome boiler. They employed a cylinder and piston in these experimental engines, but compression and ignition had not been accomplished. The system that carried over from the steam engines using atmosphere and vacuum to move the piston in the cylinder did not work and they could not overcome the difficulty of scaveing (sic) the combustion area. The mechanical design posed the greatest problems, as we see many old ideas used in these engines. Such devices as tried by Huygens in his endeavor to provide ignition to the power fuel, is an example. He fixed a container on the underside of the cylinder in which was a combustible material. This was ignited and he tried to suck this flame into the cylinder through a port to cause the explosion of the dry fuel. This was an idea that may have given some later inventors a clue, but it was never successful.
Chemists had been experimenting with various materials such as wood, coal and fats to make gas for artificial light. In 1794, Robert Street endeavored to produce with turpentine, a gas by evaporating it into an inflammable gas, and combining it with air on the intake stroke of the piston. This was then ignited by an external jet flame and was admitted to the combustion space when a valve was opened by the travel of the piston of his engine. This engine did show advanced ideas which were fundamental in design.
It should be mentioned here that an Italian, Alessandro Volta, in 1776 had demonstrated an electric spark. This was a development from Franklin's early discovery of electricity; however, it required many years of experimenting before electric ignition was successful.
In 1799, a French engineer, Philippe Lebow, was also experimenting with coal to make a lighting gas. He had conceived an idea to use in a cylinder of an engine to drive a piston. His early description set forth an engine that would have a double acting piston, and the gas mixture to be fired by an electric spark. He also suggested in his patent that two pumps for compressing the gas and a device to create the electric spark be made by running a generator from the engine shaft. His untimely death undoubtedly retarded the perfection of the gas engine for many years.
Samuel Brown of England, in 1823, used gas for fuel which was burned in a cylinder to create a vacuum that drove the piston. His was a two cylinder engine with piston rods connected to a walking beam. The cylinders fired alternately, producing power on each stroke.
Another Englishman, William Barnett, was issued a patent in 1838 for a single cylinder engine with pumps to compress gas and air and then admitted to the cylinder which was ignited by a gas jet flame in a hollow portion of the cylinder head. As the ignition flame was extinguished after each explosion, a second external gas flame lit the jet through a valve for the next stroke. Barnett's improved models of later years provided the fundamental theory for all future internal combustion engines, as his engines were the first to compress the fuel in a combustion space in the engine cylinder.
Upon the merits of Brown's designs, many patents were granted in France and England from 1838 to 1860. In this period, we find such men as Johnson, Dr. Drake, Degraud, Barsanti and Mattencci. The latter two men built a vertical open cylinder at the top, with a piston operating a rack and pinion. This design could have later inspired Dr. N.A. Otto, who also designed a similar engine.
A Frenchman, J.J.E. Lenoir, in 1862 is credited with the first successful gas engine to have been used for the generation of power. Then Otto and Langen of Germany made further progress in design and the first engine patents were issued in the United States in 1875.
The interesting details of the design of the Lenoir engine was the closed cylinder, like a steam engine with a packing gland around the connecting or piston rod. There was a cross head with a 'U' shaped connecting rod to the crank pin bearing. Two eccentrics, one on each side of the crank pin bearing, were used to actuate the slide valves in the cylinder intake on one side of the cylinder and exhaust on the opposite side. Gas was used for fuel, and mixed with air, then sucked into the combustion chambers at both ends of the cylinder. These engines fired at both ends of the cylinder, somewhat on the two stroke principle. Ignition was derived from a spark coil and hot plugs.
Engines were rated at 6 HP and 20 HP and were built in both France and England, and a few reached the United States. About 500 were manufactured and some historians mentioned that these engines were not completely successful, however they met with a wide application and set a general type, which was followed by gasoline engine designers for many years.