Arizona republican., 1918-07-21

Fascinating as any page in mechani- | cal warfare is "The True Story of the Liberty Motor' as told fin the Scien- tific American of June 1, 1918. It IS produced by permission and is as fol- lows;
 When Secretary Baker made the dramatic announcement last summer that new motor christened the Lib erty" had been developed by two American engineers in a five day con- | ference behind locked doors, men who | were experienced in machine design shrugged their shoulders. They knew the impossibility of designing so high | ly refined a machine as an airplane motor in such brief time, They as sumed, therefore, that the so-callcd new motor was probably standard motor in which a few notifications had been introduced; and speculation was rife as to what particular standard mo- tor had been adopted. It was at first claimed that the German motor, known as the Mercedes, formed the basis for the Liberty Motor; then other claim ants came forward.
 An air of mystery surrounded the Liberty motor from it's inception, and it Is high time that this was dispelled. Recent announcements from the war department, disclosing details of the motor and their similarity to other mo- tors of American and foreign design give us the liberty to tell here for the first time the real story of the develop ment of our standard aviation motor
 Shortly after the outbreak of the great European war, Henry Joy, then president of the Packard Motor Car company, became impressed with the importance of the airpane in modern warfare. He felt certain that before the conflict was over the United States would be involved and looking about among our motor manufacturers he realized how poorly prepared we were to produce the motive power for aerial warfare. There was no question that Europe was far ahead of us in the con- struction of airplanes and airplane mo- tors, and being a motor manufacturer himself he realized how long it would take to develop the manufacture of first class motors in this country even after we woke up to the realization of their necessity. Therefore, he urged his company to proceed at once with the development of an airplane motor which would compare favorably with the very best produced in Europe. This was in the fall of 1914.
 In the spring of 1915, work was started on such a motor, and the de- sign was completed in November of that year. The engine was ready for block test in February of, 1916 As there were no facilities for testing air plane engines by actual flights in this country the new motor was placed in racing chassis of special construction and was subjected to severe tests at lA engine was of 299 cubic inches displace- ment or just under the 300-inch racing limit established by the A. A. A. It was of the 12cylinder "V' type, with cast iron cylinder. After it had been thor oughly tested out, a second model was designed, based on the principles that had been proved out on the first model. This was of much larger design with four by six cylinders and of 905 cubic inch piston displacement. The new mo- tor was provided with an airplane pro- peller and mounted on a truck. With this unique power plant the truck was driven about the streets of Detroit. The alr-propelled truck could travel faster than any man would care to drive it. In one test, the wheels were locked and yet the truck was pushed over snow covered ground.
 III AJIll, .l5li, second engine Of this model Was completed and placed in a racing chassis It established the of hcial world record of 130 miles per hour -or a mile in 2S.76 seconds. In this second model, steel forged cylinders were used, fitted with pressed steel Jackets welded on. Considerable diff culty was at first experienced in at tempting to weld the jacket to the cyl 'nder without burning the metal or in- troducing strains in it. After con- siderable experiment it was found that the meeting edges which were to be welded, must be of the same thickness otherwise the heavier section would carry off the greater proportion of heat and the two surfaces could not be heated to the same temperature. By reducing the surfaces to exactly the same section, welding with the oxy- acetylene torch was readily accom- plished
 In the first model, the cylinders were set at angle of SO degree, following the practice used in automobile engines: but in the second model an angle of 4C degrees was adopted so as to cut down head resistance. Tests of the engine showed that there was no noticeable vibration with the cylinders set at this unusual angle, even when the engine was run at considerably reduced speed In this engine, the cam shaft was placed directly over the cylinders and the housing for the cam shaft was placed