LIBERTY MOTORS, the name applied to types of internal combustion engines produced under the direction of the Unit - ed States Government during the time of the World War.
There is a widely current impression that the Liberty motor was designed dur ing a five da;,7 conference held in Wash At the beginning of the war the Pack ard Company offered all the results of its experimentation to the government free of charge, although it had cost the Pack ard Company almost $400,000. In order that no one company should determine the policy of the government for the production of airplane motors, a confer ence was called in Washington between Mr. J. G. Vincent (afterward Colonel), chief engineer of the Packard Motor Company, and Major E. J. Hall of the Hall-Scott Company, in which confer ence the plans of the Packard Company ington in the early part of the war. As a matter of fact, it was a further de velopment and refinement of a motor which bad been made by the Packard Mo tor Company of Detroit. Early in the war Mr. Henry Joy, then President of the Packard Company, became convinced that the United States would be drawn into the struggle, and he realized that this coun try was entirely unprepared to produce a satisfactory airplane motor, so at his in stigation the Packard Company began experimentation, and produced several preliminary models which were tested and successfully used in special motor car bodies.
were studied, suggestions for improve ments made, and finally, upon the basis of the Packard's one and one-half years of experimentation, and with the co-op eration of almost every American motor builder and automobile manufacturer, plan for the motor were agreed upon. On the receipt of telegraphic instructions, the Packard Company began work upon its first model of the new motor, which was delivered in Washing-ton on July 4, 1917, announced to the public, and christened the Liberty Alotor.
It was deemed more advisable to build the Liberty motors in the then existing shops rather than build new plants for their production, and in many plants the manufacture of motors for motor cars gave way to the production of Liberty motors or their parts, and many other plants produced the tools, jigs, and other fixtures necessary for the quantity pro duction of these motors.
Up to the time of the Armistice, the government had let contracts for about 100,000 airplane motors, of which num ber about 60,000 were to be Liberty motors.
The first Liberty motor built upon the quantity production basis was shipped from the Packard plant or). Thanksgiving Day, 1917, and quantity production was so well organized that by the time of the armistice, the government had ac cepted 15,000 Liberty motors, the daily production being over 150, while England was after four years producing Rolls -Royce engines at the rate of but 59 a clay. Since this country was the only one of the powers which was producing airplane motors faster than it was pro ducing airplanes, the planes of the other nations were designed to take our motors.
Among the larger contractors were the Packard Company and the Lincoln Motor Company, which had each a con tract for 6,000 motors, the Ford Com pany with a contract for 5,000, Nordyke and Marmon for 3,000, and the General Motors for 2,000.
The early designs called for an eight cylinder motor, but demands from France caused the plans to be changed, and most of the motors built were twelve cylinder models, which weighed about 825 pounds and developed as high as 480 horse power, its weight being less than two pounds per horse power, which is considered very light.
The original motors were tested at the summit of Pike's Peak, and in a special vacuum room at the Bureau of Stand ards, both of which preliminary tests were passed satisfactorily.
The Liberty motor is a twelve cylinder, V-type motor of five inch bore by seven inch stroke, with a cubic capacity of 905 inches. The angle between the cylinders is 45°, which produces a rigid motor, and offers less resistance to the air than the generally used 60° angle. The motor is made up of individual steel cylinders. Until this motor was introduced, ' this country had not manufactured many successful steel cylindered motors, cast iron being the usual material. The early cyllnders were bored from steel castings, which was a slow and expensive process, but the Ford Motor Company soon intro duced a method of forging the cylinders out of seamless steel tubing, which by means of cylinder presses and bulldoz ers can be converted into a headed and flanged cylinder blank at small expense and with great rapidity. The cylinders are fitted with a stamped steel jacket which is welded to the cylinder. Be cause of the unequal thickness of the metal in the cylinder, and the jacket, dif ficulties -were experienced in the welding of the parts because of the unequal heat ing, but they were overcome by raising joining flanges upon the heavier cylin der, to which flanges the jacket was welded.
Ignition caused some difficulty, and various types of magnetos and ignition devices were experimented with before a specially designed Delco system was used. The pistons of the Liberty motor are of Hall-Scott design, the connecting rods are of the forked type such as were first used in America by the Cadillac, the crank shaft is a standard twelve-cylin der type except for the special oiling de vices. A special pump pressure oiling device is used. The water is kept in circulation by a pump developed by the Packard Company, a special carburetor was designed for this motor, and the shaft drive was developed by the Hall Scott Company. There is one cam shaft for each set of cylinders. The valves are set in the head of the motor and are operated by a mechanism more or less resembling that of the German Mercedes. The inlet valves of the motor are on the inside, in order that the travel of the gas may be shortened, while the exhaust valves are located on the outside.
The motor was subject to the most se vere tests, and may be cited as a great triumph of American engineering and methods.