FlightGlobal.com
Home
Premium
Archive
Video
Images
Forum
Atlas
Blogs
Jobs
Shop
RSS
Email Newsletters
You are in:
Home
Aviation History
1926
1926 - 0658.PDF
18 SEPTEMBER 9, 1926 when it develops 65 h.p. ; when speeded up to the maximumof 2,035 r.p.m. it develops 75 h.p. The weight, complete with magneto, carburettor, air intake, exhaust pipes, air-screw boss, etc., is 168 lbs., or 2 -5 lbs. per h.p. The cylinders are of steel, with aluminium-alloy semi-spherical heads shrunk, screwed, and lock-ringed on ; the valve seats and plug bosses are also shrunk in. Each cylinderhas two inclined valves, cobalt-chrome steel for the exhaust and stainless steel for the inlet.The crankshaft runs on ball bearings, the front main one taking the thrust. The master connecting rod is in onepiece, and the master ring and auxiliary rods are of " H " saction. The " Y " alloy forged pistons are provided withtwo rings, and a s:raper ring above the floating gudgeon-pin and another below it. The petrol consumption at the rated h.p. is 0-575 pints perb.h.p. hour, and the oil consumption 1 pint per hour. H H H 0 The A.B.C. "Scorpion Mark II" In stating, in our issue of July 29, that but one new enginehad been produced for the forthcoming light 'plane competi- tion at Lympne for the Daily Mail prizes, we were appar-ently not entirely correct, since we now learn that the A.B.C. "Scorpion" which is being fitted in the Westland "Wood-pigeon" and Short "Satellite" machines competing at Lympne, is the " Mark II," which is an entirely new design,and should in no way be confused with the " Scorpion " engines used in earlier competitions. The " Scorpion Mark II " is, like the older engine, a flattwin air-cooled, with a cylinder capacity of 1,500 ex., a bore of 4-015 in., and a stroke of 3-6 in. The normalrevolutions are 2,300 r.p.m., at which speed the engine develops 34 h.p. The maximum permissible speed is 2,530r.p.m., corresponding to a power of 39 b.h.p. Actually the power still continues to increase, as the accompanying powercurve will show. The magneto fitted is a B.T.H. with impulse starter, whilethe carburettor is a special Zenith twin. The A.B.C. " Scorpion II ": This power curve indicatesthat the engine develops just over 40 h.p. at 2,750 r.p.m. The weight of the engine is 106 lbs. Avro " Avis" and A.N.E.C. " Missel Thrush " Lympnemachines, passed its 100 hours' type test during the end of last year with very satisfactory results. The " Thrush "is a 3-cylinder air-cooled radial of inverted Y-type, with a NEW ENGINE FOR LYMPNE : The A.B.C. " Scorpion II," which has recently passed the Air Ministry Type Tests. The engine is here shown in front and rear views. Low petrol and oil consumptions are features of the" Scorpion II," the former being 0'52 lb./h.p./hour at normal revs, (i.e., 17-68 lb./hour), and the latter 0-039 lb /h p./hour(1-326 1b./hour). ' As the machines into which the engine is being fitted arelikely to fly at round about 70 m.p.h. at normal power, and the engine develops this power at the relatively low speedof 2,300 r.p.m., the propeller efficiency should be quite good. The weight of the " Scorpion II " is 106 lb., correspondingto a weight of 3-1 lb./h.p. on a basis of normal power, and 2-72 Ib./h.p. on maximum power. H H S H The Blackburne " Thrush "A 1,500 c.c. 3-Cylinder Radial The Blackburne " Thrush," produced by Burney andBlackburne, of Bookham, Surrey, and which is fitted in the capacity of 1,500 c.c. Generally it is similar to the 1924model, but differs, apart from the increase of capacity, in several detail improvements, which have resulted in a con-siderable increase of efficiency. It weighs, including oil sump, exhaust pipes, induction andignition system, starter, propeller hub, etc., 132 lbs. The normal speed of the engine is 2,500 r.p.m., allowing fordirect drive with reasonably good air-screw efficiency, and the power developed at this speed is 35 b.h.p. A maximum oi38 b.h.p. is developed at top speed, which is 2,750 r.p.m. Thus the weight per h.p., based on normal power, is 3-77 lbs.per h.p., and whilst this figure is not exceptional as regards lightness, the " Thrush " scores considerably in the matterof strong but simple construction and low fuel consumption. The cylinders, having a bore of 81 mm. and.,stroke of96-8 mm., are of steel, with detachable cast-iron heads carrying, the overhead valves. The cylinders are secured to 582
Sign up to
Flight Digital Magazine
Flight Print Magazine
Airline Business Magazine
E-newsletters
RSS
Events
