FlightGlobal.com
Home
Premium
Archive
Video
Images
Forum
Atlas
Blogs
Jobs
Shop
RSS
Email Newsletters
You are in:
Home
Aviation History
1946
1946 - 0023.PDF
JANUARY 3RD, 1946 FLIGHT 11 Armstrong Siddeley , Cougar A New M^edium-power Engine in the Famous "Feline" Range GOUGAR is the name given to a new engine now beingdeveloped by Armstrong Siddeley Motors, Ltd.,which thus retains the feline ancestry founded by the Siddeley Puma in the first world war and carried onin all subsequent Siddeley engines. There have been Tigers, Leopards, Jaguars, Lynxes, Cheetahs, Genets andMongoose, but the new engine differs from them all, not only in being the first nine-cylinder single-row radial tobe produced by the firm, but in many of its basic details. It is not yet in production but tests have been very satis-factory . The Cougar is intended for use in medium-size transportaircraft and the larger type of single-engined trainers, and the relatively small diameter (49.5m.) coupled with closebaffling, makes for a neat installation. The engine is geared and supercharged and drives a Rotol constant-speed, fullyfeathering three-bladed airscrew. For a take-off power of 850 b.h.p. the engine has a net weight of 1,020 1b. Amongthe new features is a R.A.E.-Hobson fuel injector and metering unit in place of the carburettor. Cylinder Design Departure In the design of the cylinders the Armstrong-Siddeleyengineers have departed completely from their previous practice. A steel barrel is shrunk and screwed into analuminium alloy head, and is secured to the crankcase by 16 studs. Two valves are fitted, and the exhaust valveis sodium cooled. The crankcase is a one-piece aluminium alloy casting,closed at each end by diaphragm'plates which carry the front and rear roller journal bearings for the split Maneton-type crankshaft. The master connecting rod is an air- hardened steel stamping to which the eight auxiliary rodsare hinged by plain anchor pins secured by circlips at each end. Pressure oil fed through the hollow crankshaft lubri-cates the white-metal one-piece big-end bearing and the anchor-pin bushes in the auxiliary rods. Floating steelbalance weights are attached to edch crankshaft web and act as vibration dampers. / V Valve operation is by a two-Vrack cam drum (four camson each track) running at one-eighth crankshaft speed and in the opposite direction, and actuating the tappetsthrough push-rods and rockers. The whole valve gear is totally enclosed. The supercharger impeller is driven at8.17 times engine speed via a spring drive and a centrifugal clutch. At the front of the engine is the airscrew reduc-tion gear, which is of the epicyclic type, and at the back is a drive for a Rotol remote accessories gear box. The R.A.E.-Hobson fuel injection and metering unit isfully automatic and corrects for boost pressure, altitude, exhaust back pressure and temperature. It also embodiesa fuel pump and fuel cut-off. The fuel is fed direct to the centre of the supercharger rotor, in which it is finelyatomised. There is also a boost control acting through bell-crank levers on the twin throttles. Both throttlesand throttle box are oil heated, and the system completely eliminates the possibility of throttle-icing. ARMSTRONG-SIDDELEY COUGAR Single-row air-cooled 9-cyl. radial. Geared and Moderately Supercharged. Bore, 5.5in. ; stroke. 5.5in. Capacity, 1,176 cu. in. (19.28 1.). Length, 5l.5in., diameter, 49.5in. ; reduction-gear ratio, 0.589 ; I. Supercharger drive ratio, 8.17 : I ; airscrew rotation L.H. tractor. International rating, 690 b.h.p., 2,500 r.p.m.. + 5.5 Ib./sq. in. Max. power rating, 730 b.h.p., 2,700 r.p.m., ~ 5.75 Ib./sq. in. booit b.h.p. r.p.m. (Ib./sq. in.) At max. cruising (rich mixture) ... ... 560 At max. cruising (weak mixture) ... 450 At max. climb conditions ... . ..^ ... 660 At max. level conditions 690 At max. take-off conditions (sea level) ... 850 Net dry weight, 1,020 Ib. r.p.m 2,300 2,300 2,500 2,700 2,800 + 3.25 -i- 0.5 •4- 5.5+ 5.75 + 10 A; 400 4 5 6 7 8 9 ALTITUDE IN THOUSANDS OF FEET Projected ratings for the Cougar. R.Ae.S. BIRTHDAY CELEBRATIONS S related elsewhere in this issue, the Royal AeronauticalSociety celebrates its Soth birthday on January 12th. To mark this notable occasion, two celebrations are being heldin London. On Friday, January nth, the Society is to hold a dinner at the Guildhall for its members and a few distinguishedguests. Invitations have been accepted'by, among others, the Ministers of Civil Aviation and Aircraft Production and Supply,the First Lord of the Admiralty, Lord Trenchard, Lord Dowel- ing and a number of R.A.F. ('ommanders-in-Chief. On the following day the president, Sir Frederick HandleyPage, and the council will hold a reception for members and friends at 4, Hamilton Place, from 3 p.m. to 6.30 p.m. Ad-mission to both gatherings will be by ticket only, obtainable from the secretary.The various provincial branches of the K.Ae.S. will hold their own celebrations during the coming month. To commemorate the occasion, the R.Ae.S. has prepared anillustrated history of British aviation during eighty years. Copies can be obtained from the secretary, at 4, HamiltonPlace, London, W.i.
Sign up to
Flight Digital Magazine
Flight Print Magazine
Airline Business Magazine
E-newsletters
RSS
Events
