CHAPTER VII

DEVELOPMENT OF THE LIBERTY AND OTHER MOTORS

DEBATE IN REGARD TO ORIGIN OF LIBERTY MOTOR—LIBERTY-ENGINE CONFERENCE, DESIGN, AND TEST—MAKERS OF PARTS—HISPANO-SUIZA MOTOR—ROLLS-ROYCE—OTHER MOTORS

There has been more discussion of the Liberty motor than any other motor made during the war. This was due to the publicity given to the motor by the publication of a romantic story of the motor, issued from Washington over the signature of Secretary of War Baker, to the effect that the motor was conceived in a few days, and built and perfected within a month. Of course every engineer knows that that could not be done, and it took at least six months before the Liberty engine was perfected, and this was long after the Creel Publicity Bureau in Washington issued its statement.

As we have pointed out elsewhere, if the Aircraft Production Board had taken the patterns of a standard motor like the Hispano-Suiza, which had been flown for nearly three years under all kinds of war conditions, and which was being built in this country, and if they had ordered gigs, dies, and tools, and when we entered the war had requested our engineers to follow Chinese patterns in the making of the same, the dies, gigs, etc., could have been made at once instead of months later, and many American-made aircraft could have been operating over the lines when the Americans began to fight at Château-Thierry, and not months later, as was the case. Undoubtedly this delay cost the lives of thousands of American soldiers, and set back the Allied victory by just so much. The failure to deliver aircraft on schedule was the reason why General Pershing had to demand haste in the production of machines. Regardless of the fact that the aeroplane motor is radically different from the automobile motor, because it must be much lighter, nevertheless automobile men were called in by the Aircraft Production Board to design the Liberty motor, and many of the engine-building companies that had been constructing aeronautical motors were not consulted.

After the Liberty engine was completed a lively debate was instituted as to which of the two companies that was represented at the designing of the engine deserved the most credit for the job. One of the automobile companies advertised the fact that they were responsible for the Liberty motor, and the other company immediately replied, trying to prove that because they had built successful motors before the war that they were the real designers of the motor.

To be sure, no one would have objected to the construction of a Liberty motor on the side, but to delay the construction of motors in quantity until September, 1917, put the United States back just six months in production, for a number of factories were already producing parts for Rolls-Royce engines, and the Wright-Martin Company had been building the Hispano-Suiza motor since January, 1916.

Be that as it may, the facts regarding the Liberty motor appear to be that General Squier, E. A. Deeds, Howard E. Coffin, S. D. Waldon, of the Aircraft Production Board, called in to consultation on May 29, 1918, E. J. Hall, chief engineer of the Hall-Scott Motor Company, builders of a number of 4, 6, 8, and 12 cylinder aeroplane engines, and Jesse G. Vincent, experimental engineer of the Packard Motor Car Company, who had just completed a design and an experimental aeroplane engine, which had never up to that time been in a plane.

Both these gentlemen were in Washington attempting to interest Signal Corps officials in the aeroplane engine each had designed.

LIBERTY-ENGINE CONFERENCE

A five-day conference between Mr. Hall and Mr. Vincent, called by Mr. Deeds and Mr. Waldon of the Aircraft Production Board to consider aeroplane-engine design and production, was held. The two engineers got together in designing a standardized, directly driven, five-bearing crank-shaft engine of 8 cylinders, and one of 12 cylinders, with a seven-bearing crank-shaft. After a session of twenty hours’ work in a room at the New Willard Hotel, in Washington, during which meals were served the two men, and both lived, worked, and slept in the apartments of Mr. Deeds, a new 8-cylinder 230 horse-power aeroplane engine was laid out, described, and drawings of transverse and longitudinal sections were made by Vincent and Hall themselves. This was the first Liberty motor designed.

On the morning of May 30, 1917, near the close of the designing session, Mr. Vincent dictated a joint report to the Aircraft Production Board. The salient points and a rough draft had been agreed upon the night before. It was dated May 31, 1917, and signed jointly by E. J. Hall and Jesse G. Vincent.

WASHINGTON, D. C., May 31, 1917.

AIRCRAFT PRODUCTION BOARD, WASHINGTON, D. C.

_Gentlemen_: At your request we have made a careful study of the aircraft motor situation and hasten to submit our report as follows:

In order to get this report in your hands promptly we have condensed it as much as possible and have covered the essentials only.

In view of the fact that there are a number of good motors for training-machines available, we have disregarded this type of motor and have confined our attention strictly to the high-efficiency, low-weight per horse-power type, such as is necessary at the front.

In order that any motors that are built by this country may be of any value when received at the front, it is, of course, absolutely necessary that their efficiency be brought up to or a little beyond the best now available in Europe. This, of course, made it necessary for us to know just what has been accomplished in Europe. The French and English Commission has enabled us to obtain this information by answering our questions very clearly and completely.

From information obtained from these gentlemen and from other sources, we believe that the Loraine Dietrich is the coming motor in Europe. This motor has not been built in large quantities as yet, but some thirty had been constructed and carefully tested out at sea-level and also at about 6,000 feet elevation. The important facts about this motor are as follows:

Eight cylinders: 120 mm. bore by 170 mm. stroke.

Cylinders made of steel with water-jackets welded on. Motor is direct-driven and develops 250 horse-power at 1,500 r. p. m., and 270 horse-power at 1,700 r. p. m. The weight of the bare motor is 240 kilos, or approximately 528 pounds, while the weight of the motor complete with radiator and water is 305 kilos, or 671 pounds. There seems to be a reasonable doubt regarding the exact weight of the bare motor, as while the French Commission gave us the figure of 528 pounds, information from other sources indicates a weight of 552 pounds; probably some intermediate figure is more nearly correct, but in any event the motor gives a horse-power for approximately two pounds of weight when figured at its maximum output of 270 horse-power.

After obtaining this information and considering the matter very carefully, we next investigated the matter of testing such a motor, as we knew that a motor of this type could not be run at full power for long periods of time without developing serious trouble. Here again the French Commission gave us valuable information. They stated that in using a motor of this type it is only run at full power for short periods of time while climbing or fighting, and that all other times it is run at speeds 200 to 300 r. p. m. slower. In view of the fact that the motor is built to run under these conditions, it is, of course, necessary to test it under similar conditions, and they stated when trying out a new model of motor it is their practice to mount a propeller which will just hold the motor down to maximum speed under full throttle. The motor is then run for fifty hours, in periods of six to eight hours each, but the motor is not run up to full speed for more than a total of ten hours during this entire period, nor is it run more than thirty minutes at any single time under this condition. The other forty hours’ running is under throttled conditions, turning the same propeller 200 to 300 r. p. m. less than maximum speed.

This information is of the utmost importance, as it enables us to reduce all factors of safety and make possible the light-weight per horse-power now being obtained in Europe.

After obtaining this information we immediately laid down a proposed motor which we believe can be produced promptly in large quantity in this country. Built carefully out of proper materials, this motor will have approximately the following characteristics and be as good, or a little better, than the Loraine Dietrich, which is not as yet really available abroad.

In laying down this motor we have without reserve selected the best possible practice from both Europe and America. Practically all features of this motor have been absolutely proved out in America by experimental work and manufacturing experience in the Hall-Scott and Packard plants, and we are, therefore, willing to unhesitatingly stake our reputations on this design, providing we are allowed to see that our design and specifications are absolutely followed.

The motor is to be of the eight-cylinder type, with cylinders set at an included angle of 45 degrees. The cylinders are of the individual type, made out of steel forgings with jackets welded on. The bore is five inches and the stroke seven inches, giving a piston displacement of 1,100 cubic inches. The crank-shaft is of the five-bearing type with all main bearings 2⅜ inches in diameter, and all crank-pin bearings 2¼ inches in diameter. The connecting-rods are of the I-beam straddle type. This motor is of the direct-driven type with a maximum speed of 1,700 r. p. m. This motor will have a maximum output of 275 horse-power at 1,700 r. p. m. It will weigh 525 to 550 pounds, but we feel very sure of the lower figure. It will have a gasoline economy of .50 pounds of fuel per horse-power hour or better; it will have an oil economy of .04 pounds of oil per horse-power hour or better. Complete with water and radiator, this motor will not weigh more than 675 pounds, if a properly constructed radiator is used and placed high above the motor.

To obtain the above-mentioned weights it will be necessary to use the fixed type of propeller hub which has been thoroughly proved out by Hall-Scott practice. In order to obtain the above-mentioned weights it will also be necessary, as mentioned above, to use the very best material, workmanship, and heat treatment.

Complete detail and assembly drawings, as well as parts list and material specifications, can be completed at the Packard factory under our direction in less than four weeks. We believe that a sample motor can also be completed in approximately six weeks if money is used without stint. As soon as the drawings, specifications, and sample motor have been finished, complete information would, of course, be available so that any high-grade manufacturer could either make parts for this motor or manufacture it complete.

In laying down this design we have had in mind the extreme importance of interchangeability, as a well-laid, comprehensive programme which has for its base interchangeability of important parts, such as cylinders, will speed output and reduce ultimate cost to an astonishing extent. Europe is suffering right now from lack of uniformity of design, but it is too late for them to change their plan. We, however, can take a leaf out of their book and start right.

In the design which we have laid down, the cylinder, for instance, can be used to make four, six, eight, and twelve cylinder motors. As this is the most intricate part to make, immense facilities could be provided to produce them in large quantities for the use of many concerns who could manufacture the balance of the motor. Nearly all small parts and numerous large and important ones would also be interchangeable. This would not only speed up production but would be of the utmost importance in connection with repairs and replacements. A full line of motors made according to this plan would line up about as follows:

Rated Maximum Weight per Type Horse-power Horse-power Weight Horse-power 4 110 135 375 2.7 6 165 205 490 2.3 8 225 275 535 1.9 12 335 410 710 1.7

Respectfully submitted, (_Signed_) J. G. VINCENT. (_Signed_) E. J. HALL.

On June 4 Hall and Vincent finished a layout of an 8-cylinder engine, and presented the drawings and received an order to build ten sample engines, and on June 8 the Packard Company arranged for pattern-making, production work, etc.

This motor after intensive work on detail drawings was put into preliminary production. The first one was delivered to Washington, July 3, 1917. In the making of the sample engine Mr. Vincent’s company placed its factory organization at the disposal of the government, and through Mr. Vincent’s untiring efforts and enthusiasm the first motor was completed within the sixty days.

The other companies which aided in the work of building this motor were:

The General Aluminum and Brass Manufacturing Company of Detroit made bronze-backed, babbitt-lined bearings and aluminum castings.

The Cadillac Motor Car Company of Detroit made the connecting-rods, connecting upper-end bushings, connecting-rod bolts, and rocker-arm assemblies. The Cadillac Company had perfected the design of connecting-rods of the forked or straddle type, and had been using them for several years in their 8-cylinder engines.

The Parke Drop Forge Company of Cleveland made the crank-shaft forgings. These forgings completely heat-treated were produced in three days, simply because Mr. Hall gave them permission to dig out the Hall-Scott dies which were used in making the first Liberty crank-shaft forgings.

Hall-Scott Motor Car Company of San Francisco supplied all the bevel-gears out of its stock for the standardized line of Hall-Scott 4, 6, 8, and 12 cylinder aeroplane engines.

The L. O. Gordon Company of Muskegon made the cam-shafts.

The Hess-Bright Manufacturing Company of Philadelphia made the ball-bearings.

The Burd High Compression Ring Company of Rockford, Ill., supplied the piston-rings out of stock made up for the Hall-Scott line of standardized aeroplane engines, for which it had perfected a piston-ring.

The Aluminum Castings Company of Cleveland supplied the die-cast alloy pistons, and machined them up to grinding, as they had been engaged in making them for several years for the Hall-Scott line of standardized aviation engines.

The Rich Tool Company made the valves.

[Illustration: The Martin bomber.

This plane is equipped with two Liberty engines and has many long-distance records. It flew from Pittsburgh to Washington, a distance of 175 miles, in 1 hour and 15 minutes. It also flew from the Atlantic to the Pacific.]

The Gibson Company of Muskegon made the springs.

The Packard Company made the patterns and several dies in order to obtain drop-forgings of the proper quality. It also machined the crank-shafts.

After the preliminary tests passed by the 8-cylinder engine, August 25, 1917, Government Inspector Lynn Reynolds said “that the design has passed from the experimental stage into the field of proven engines.” The machine was tested at Pike’s Peak, Colorado, for altitude in August, 1917. Reports from the battle-field decided the board to build 12-cylinder engines. Thereupon standardized parts made interchangeable for all types of Liberty engines were detailed, and orders placed with the various firms named to build the same. Production was started on a large scale.

On October 17 the production of the Liberty motor started, over six months after we entered the war.

The delivery of the first Liberty 12 was made on Thanksgiving Day, 1917.

One of the unrecorded incidents of this period concerned the “scrapping” of $400,000 worth of semi-finished parts of an automotive aircraft engine, which was assumed O. K., and parts had been ordered for 250 motors. It was actually in production at the time Hall and Vincent were ignoring practically all its features and “laying out” the designs for the Liberty 8 and Liberty 12. It had never been tested in a plane, and its design and all its parts were rejected.

Owing to the slowness of production due to the new gigs, dies, tools, etc., necessary to build the engines, much criticism was directed at the lack of shipments of Liberty engines for army air service in the winter months of 1917.

Charged with the necessity of protecting the American army transport, the Navy Department had first call on all air-service equipment. As a result it received the first Liberty 12’s turned out. These were installed in navy aeroplanes, where they did good work.

The preliminary Liberty 8 was delivered to the Bureau of Standards, Washington, D. C., July 3, 1917, by the group of industrial concerns named. A 54-hour test was made of a Liberty 12 on August 25 by the Bureau of Standards. The Liberty 12 was detailed for quantity production, and the actual work was begun, and the work done by these companies in producing Liberty-engine parts is above praise. It was then that the mighty energies of their splendid organizations demonstrated the ability of American industrial life to fight the battle behind the lines.

WAR DEPARTMENT STATEMENT

Departing from its policy of secretiveness concerning all things of a military character, the United States War Department on May 15, 1918, issued an authorized statement dealing with the technical features and characteristics of the Liberty 12, then in quantity production. This statement was published in the _Congressional Record_ of an early subsequent date.

Secretary of War Baker in his report published elsewhere in this book gives the following account of Liberty motors built:

PRODUCTION OF SERVICE ENGINES

In view of the rapid progress in military aeronautics, the necessity for the development of a high-powered motor adaptable to American methods of quantity production was early recognized. The result of the efforts to meet this need was the Liberty motor—America’s chief contribution to aviation, and one of the great achievements of the war. After this motor emerged from the experimental stage, production increased with great rapidity, the October output reaching 4,200, or nearly one-third of the total production up to the signing of the armistice. The factories engaged in the manufacture of this motor, and their total production to November 8, are listed in Table 21.

TABLE 21.—PRODUCTION OR LIBERTY MOTOR TO NOVEMBER 8, 1918, BY FACTORIES:

Packard Motor Car Co 4,654 Lincoln Motor Co 3,720 Ford Motor Co 3,025 General Motors 1,554 Nordyke & Marmon Co 433 ——— Total 13,396

Of this total, 9,834 were high-compression, or army type, and 3,572 low-compression, or navy type, the latter being used in seaplanes and large night bombers.

In addition to those installed in planes, about 3,500 Liberty engines were shipped overseas, to be used as spares and for delivery to the Allies.

Other types of service engines, including the Hispano-Suiza 300 horse-power, the Bugatti, and the Liberty 8-cylinder, were under development when hostilities ceased. The Hispano-Suiza 180 horse-power had already reached quantity production. Nearly 500 engines of this type were produced, about half of which were shipped to France and England for use in foreign-built pursuit planes.

Table 22 gives a résumé of the production of service engines by quarterly periods:

TABLE 22.—PRODUCTION OR SERVICE ENGINES IN 1918:

Jan. 1 to Apr. 1 to July 1 to Oct. 1 to Name of engine Mar. 31 June 30 Sept. 30 Nov. 8 Total Liberty 12, Army 122 1,493 4,116 4,093 9,824 Liberty 12, Navy 142 633 1,710 1,087 3,572 Hispano-Suiza 180 h.p. ... ... 185 284 469

Later the Statistical Department of the War Department issued the following. The number of planes and engines shipped by the Bureau of Aircraft Production to depots and storehouses from the date of the armistice to February 14:

Liberty 12 service engines 4,806 OX-5 elementary training-engines 1,261 Le Rhone advanced training-engines 994 De Havilland-4 observation planes 524 Hispano 180 advanced training-engines 343 Hispano 150 advanced training-engines 254 JN6-H advanced training-planes 174 JN4-D elementary training-planes 131

The Packard Motor Car Company made the final deliveries of Liberty 12 motors during the week ended March 21, 1919. This completes all contracts. The following shows the number and per cent produced by each factory:

Number P.C. Firm produced of total Packard Motor Car Co. 6,500 32 Lincoln Motor Co. 6,500 32 Ford Motor Co. 3,950 19 General Motors Co. 2,528 12 Nordyke & Marmon Co. 1,000 5 ——— Total 20,478

THE HISPANO-SUIZA

It is evident from the records made by the German Mercedes, which are given in another chapter, that it was the best aviation motor in existence in July, 1914. Naturally, this motor had considerable influence on the aeronautical engineers of the Allies. Mr. Marc Birkright, a Swiss engineer to the Hispano-Suiza Company, automobile builders in Barcelona, Spain, and Paris, designed the aviation motor which now holds the world’s record for altitude—28,900 feet. When he designed the motor he had in mind the construction of the machine-tools necessary to build the same.

In the summer of 1915 the first motor of 150 horse-power was delivered to France after a test of 15 consecutive hours. The next two were tested for 50 hours, and proved satisfactory. France placed a large order, and the Hispano-Suiza factory began production at the end of 1915. Before the end of the war three Italian, fourteen French, one British, one Japanese, and one Spanish factory, besides 25,000 people in America, were producing Hispano-Suiza engines.

The motor had great success in the single-seater fighters flown by such men as Captain Georges Guynemer, Lieutenant Fonck, Nungesser, and dozens of other aces.

With the exception of increasing the horse-power from 150 to 180, 200, 300, very few changes were made in this motor in this country.

Four hundred and fifty engines were ordered by the French Government of the General Aeronautic Company of America early in 1916. When the Wright-Martin Aircraft Company was formed in September of that year, less than 100 motors had been delivered. At the end of July, 1917, 1,000 motors were on their books.

From July, 1917, the American factory concentrated on the 150 horse-power engine. The Wright-Martin Company had to build its own plant for aluminum castings for the engine. In November of that year the company was ordered to build 200 horse-power engines, and later the 300 horse-power was ordered. In May, 1918, the French and British Governments decided to use the 300 horse-power motor in large quantities, and by October the factories of the company in New Brunswick and Long Island City were tooled up to produce 1,000 motors a month, which represented a $50,000,000 order. Early in the spring of 1918, 15 motors a day were produced, and in August of that year the company was committed to a schedule of 30 engines a day.

THE ROLLS-ROYCE MOTOR

“There is no doubt,” says _London Motor_, “that the conception of the Rolls-Royce aeronautic engine is extremely good, but no one will gainsay the fact that the care exercised in manufacture and the elaborate operations through which the various parts have to pass are in part the reason for its success. This refinement necessitates the passing of certain parts through fifty or sixty operations that might be easily carried out in a comparatively small number if superfine finish were not desired or required.

“The Rolls-Royce ‘Eagle’ engine, originally designed as a 200 horse-power unit, developed 255 horse-power on the first brake test. Diligent research and experiment were pursued with extraordinary results, as will be seen in the following record of official brake tests, all made without any enlargement of the dimensions or radical alteration in design. A 12-cylinder engine, 4½-inch bore by 6½-inch stroke, developed in March, 1916, 266 horse-power at 1,800 R. P. M. By July the power was increased to 284 horse-power; nine months from this date, in September, 1917, it had risen to 350 horse-power, and in February, 1918, 10 more horse-power was added, making the total 360 horse-power. In addition to the ‘Eagle,’ a smaller engine giving 105 horse-power at 1,500 R. P. M. was turned out under the name of the ‘Hawk.’

“The ‘Eagle’ engine was used in the large Handley Page machine, and in the successful long-distance bombing raids into Germany. In 1916 another engine for fighting planes was added to the list, under the name of ‘Falcon,’ and was almost exclusively used in the Bristol fighting plane. The increase in the power developed by the ‘Falcon’ engine, which has a 4-inch bore, was as follows: April, 1916, 206 horse-power at 1,800 R. P. M.; July, 1918, 285 horse-power at 2,000 R. P. M.

“From the stamping-plant through the machine, gear-cutting, and grinding shops and welding department, the care with which each engine is turned out is apparent. Take apart a cylinder which has a stamped sheet-metal water-jacket welded externally, and the original billet is found out of which the cylinder was made, but reduced almost by half when it is ready to receive the valve cages, and during the process of removal of the metal and forming into proper shape the piece is subjected to several heat treatments so as to bring the metal to that stage of perfection needed for the work it has to perform. The elbow cages that are fitted to the cylinders might be cast and cored, but the valve cage is an actual solid stamping, and the right-angle bend through the elbow has to be bored out by special machines.

“One point illustrates the care in the choice of metal and the multifarious operations through which each part has to pass. A crank-shaft stamping with extension piece on the rear and about one foot long is cut off, and test pieces of this metal, properly numbered with each crank-shaft, are passed through the same treatment as the crank-shaft itself, and then subjected to minute examination by highly skilled engineers. The actual manufacturing side of the work would naturally be very similar to the manufacture of a car engine, but one obtains a better perspective of what an engine is subjected to by passing from the erecting and manufacturing shops to the engine-testing shop, where the ear-splitting reports from the open exhausts of a number of engines being tested at the same time are heard. Here one sees how dissimilar the aviation engine is from the car engine. It is almost impossible, without having actually witnessed it, to picture to oneself a 12-cylinder engine running at 2,200 R. P. M. against a brake test. As the exhaust ports are on either side of the engine, the cylinders being placed in the form of a V, it is possible, by passing on either side, to look into the combustion-chamber and see the valves rising and the spit of the exhaust, and, what is almost incredible, that the exhaust valves are actually red-hot and run in this condition for hours. Little wonder is it that the valves have to be made of superfine material and of particular form.

“The variation in the color of the flame of the exhaust, due to strong and weak mixtures, makes it quite possible to test the good running of an engine by the color of its exhaust. The strength of the mixture has necessarily to be altered according to atmospheric conditions and the altitude to which the pilot desires to climb.

“No doubt airplane-engine practice of the last four years and the advance that it has made will be reflected in a very marked degree in the automobile, not necessarily by fitting large airplane engines in cars, but by applying to car practice the knowledge that has been gained in manufacture.

“The Rolls-Royce works had in 1907 an area of 5,312 square yards, and during the war this was increased to 67,935 square yards. At the present time the payroll is somewhere in the neighborhood of 8,650.”

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