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Aviation History
1922
1922 - 0119.PDF
FEBRUARY 23, 1922 " Lion " what it is, yet on account of its greater power differing essentially from that engine in many respects. The result was the 1,000 h.p. engine, which made its first appearance last year. Already that engine has won to the distinction of having a nickname, being affectionately known as the "Cub." This first 1,000 h.p. engine was illustrated and described in FLIGHT of February 10, 1921. On its first test that engine developed 1,057 b.h.p., and as its weight was approximately 2,200 lbs., it will be seen that it worthily maintained the Napier reputation for light weight. Just recently the second " Cub," has been completed, and this was the occasion of a visit, by chiefs of the Air The 1,000 h.p. Napier "Cub" on the test bench, running at about 1,200 r.p.m. When the photograph was taken the engine had not been running long, and was not yet allowed to run at full power. Ministry and other influential personalities, on February 16, to the huge Napier works at Acton. Among those received by Mr. H. T. Vane, C.B.E., Managing Director, and Sir Harry Brittain, K.B.E., Director, were :—Lord Gorell, C.B.E., M.C., Major Sir Phillip L. Greame, K.B.E., M.C., Major-General Sir Frederick Sykes, G.B.E., K.C.B., C.M.G., Sir Wm. Joynson-Hicks, M.P., Major-General Sir Sefton Brancker, K.C.B., Sin Wm. Bull, M.P., Lieut.-Col. Moore- Brabazon, M.C., M.P., and Mr. A. Baldwin Raper, M.P. The visitors were conducted over the works in parties, each under an expert guide, and thus had an opportunity of witnessing the actual production of the Napier aero engines. From beginning to end the Napier engines are made with the most minute care, all materials being subjected to chemical and physical tests before being allowed to be incorporated in the engines, In a well-appointed laboratory, chemists were at work with their retorts, ovens and other paraphernalia of the " lab," and in another part Izod, Brinell and similar physical tests were being carried on. In the shops the visitors saw the different parts being manufactured on the most up-to-date machinery, and erected and assembled on special jigs and benches. It is impossible, in the space available, to give an idea of the innumerable operations necessary before a finished engine emerges and is taken to the test house for its running tests. Suffice it to state that everywhere the greatest possible care is being taken to ensure the excellent workmanship and superb finish for which the Napier engines are rightly famous. Rows upon rows of Napier " Lions " were ready for ship ment, many of them to foreign governments. Others were roaring in the test house. But among all the activity, the most interesting part, from the visitors' point of view, was, undoubtedly, the manufacture and testing of the mighty " Cub." With its cylinders arranged somewhat in the manner of a letter X, although the arms are not evenly spaced, the upper rows being placed at a smaller angle to each other than that which separates the lower rows, the " Cub " is of astonishingly short length, considering its power. The large cylinders have sheet steel water jackets welded on, and each cylinder has two inlet and two exhaust valves. The aluminium crank case on which the cylinders are . mounted, is strongly webbed for rigidity, as shown in one of our photographs, and carries at its front end the housing for the large reduction gear, which is also shown in a photo graph. The connecting rod assembly is of interest inasmuch as *.^.ere is one master rod, to which are attached the three auxiliary rods, one of them to the cap of the big-end. The crankshaft, as will be seen from one of the photo graphs, is of ample dimensions, and runs on very large roller bearings. The manner in which these are slipped over the webs and crank pins into position, and locked, is highly ingenious, and must have taken a great deal of thinking-out. Owing to the size of the roller bearings, the peripheral speed must be very high, but we understand that no trouble whatever has been experienced from this source. The large size was necessitated by the insistence of the designers to have a crankshaft of such diameter as to ensure rigidity, and con sequent smoothness of running and absence of wear and tear. That this object has been attained appears certain. In the test house, visitors were allowed to witness a " Cub " on its first test. Owing to the fact that the engine had only been running for a few hours, it was not allowed to develop its full power. When we saw it the revs, indicator remained steadily on 1,200 r.p.m., with a short " burst " at about 1,650 r.p.m. We understand that full power is developed at about 2,000 r.p.m. So far the " Cub's " achievements rest on what it has done on the test bench, but in the near future, in fact, probably by the time these notes appear in print, it will be mounted in an aeroplane designed and built by a famous pioneer firm of aircraft constructors for the Air Ministry. That it will give this machine an astonishing performance, we have no shadow of doubt. Details are not permitted, but we may say that we have seen the machine, and in our opinion, the power plant is worthy of its machine, and vice versa. It is not too much to say that the advent of a 1,000 h.p. single- power unit will mark a new milestone in aerial development, and J Visiting the Napier aero engine works at Acton : Our photograph shows Mr. H. T. Vane, Managing Director of the firm, conducting a party over the very extensive works. From left to right are seen: Lord Gorell, Mr. Vane, Gen. Sir Sefton Brancker, Sir Harry Brittain, and Lieut.-Col. Moore-Brabazon. it is to be hoped that in the not too distant future this wonderful power plant will be given an opportunity of showing what it can do in a commercial machine. The number of passengers carried in a good high-performance modern aeroplane corresponds to a power expenditure of about 45—50 h.p.'passenger. For the "Cub" this would mean about 20-22 passengers. Aeroplane designers forward.^ The Napier " Lion" has already done invaluable service to commercial aviation. We can express no better hope for the " Cub " than that it may worthily uphold the traditions of its smaller prototype. 119
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