FlightGlobal.com
Home
Premium
Archive
Video
Images
Forum
Atlas
Blogs
Jobs
Shop
RSS
Email Newsletters
You are in:
Home
Aviation History
1937
1937 - 1712.PDF
640 FLIGHT. JUNE 24, 1937. (Left) An uncowled Rolls-Royce Merlin engine in a production Fairey Battle reveals the down-facing car burettor in-take with its scoop, the separate radiators and details of mounting. In contrast, below, is the finished product faired and cowled. The latest type of exhaust manifold, shown in the first illus tration, may be com pared with the more familiar stubs seen below. (Flight photo graphs.) from a Dagger III. Many points of unusual in terest are to be seen in the Dagger, in particular the self-adjusting tappets and streamlined scoop and baffling to give adequate and even cooling to all twenty-four cylinders. Known the world over as an engine of excep tional workmanship and also as the power unit of the Hawker range (Hart, Demon Fury, Audax, Osprey, Nimrod, Hind, etc.), the vee- twelve Rolls-Royce Kestrel is the only water- cooled engine in Squadron use now that the Blackburn Perths with three R.-R. Buzzard II M.S. engines are almost superseded. Available with 0.477, 0.553, or 0.632 to 1 reduction gear, the 21-litre Kestrel family, the IB (B indicates 87:1 compression ratio), then the IIS and IIIMS and, later, V, VI, and nor mally aspirated X, have given thousands of hours' service and are now handing over to the Merlin in new machines. All the supercharged Kestrels are cleared for v.p. airscrew equipment and tested for composite cooling. For this cool ing the adjustable radiator employed for a 600 h.p. engine is the same size as for the earlier engines, giving only 480 h.p. In level flight the compositely cooled engine is water-cooled entirely, but in climb a slight degree of boiling (steam cool ing) occurs at a small pressure. A few of the more ob servant folk will have noticed a swelled starboard centre- section strut fairing on some Hawker types. This carries a pipe to the condenser—part of the steam cooling system •—in the top centre section. An unsupercharged Kestrel IB or X installation, as in the Audax, can be picked out by the two small air scoops on top of the cowling feeding the twin carburettors located between the cylinder banks. The Rolls-Royce Merlin engine, designed for D.T.D. 230 (87-octane) fuel, has a 6: 1 compression ratio and is of 27 litres capacity. A 0.477 reduction gear is fitted and v.p. airscrew equip ment is specified except when installed in certain single-seater fighters such as the Spitfire or Hurricane, when the weight factor is of particular importance. Ethyl ene glycol is the cooling medium, and outlet temperatures vary from no0 to 1300 C. as a maximum. A single stream lined air scoop differing a little in the shape and position according to aircraft deals with all cooling on Merlin installa tions in the Fairey Battle, Supermarine Spitfire, and Hawker Henly. Under the shining " bonnet" of the Miles Magister is a De Havilland Gipsy Major engine.
Sign up to
Flight Digital Magazine
Flight Print Magazine
Airline Business Magazine
E-newsletters
RSS
Events
