FlightGlobal.com
Home
Premium
Archive
Video
Images
Forum
Atlas
Blogs
Jobs
Shop
RSS
Email Newsletters
You are in:
Home
Aviation History
1945
1945 - 1860.PDF
SEPTEMBER *2OTH, 1945 FLIGHT 3*5 LEADING PARTICULARS Type . . . . . . Pressure liquid-cooled, in-line Go deg. No. of cylinders .. 12, arranged in two monobloc banksof six with detachable heads. .. Coin, x 6.6in... 186.6 cu. in. . . 2,239 cu- m- (36-7 litres).,. Direct spur gear— :Ratio : 0.5102 : 1.. . Left-hand tractor. ... No. 5 S.B.A.C. Standard., . Poppet—exhaust valves sodium cooled. .. Four, quadrantly disposed... Centrifugal two-speed two-stage with inter-cooler. .. Rolls-Royce Bendix-Stromberg pres-sure injection type 9T/40/1 triple- entry up-draught. .. B.T.H. C.S.H. 12-125/3 duplex typewith integral distributors. ,. Two/cyl. diametrically opposite andradially disposed one each to inlet and exhaust sides. ,. (P = port; S = starboard) iS, 4P, 3S, 2P, 5S, iP, 6S, 3P, 4S, 5P,2S, 6P. ,. Fully advanced : Inlet plugs 45 deg.before T.D.C. Exhaust plugs 51 deg. before T.D.C.Fully retarded : Inlet plugs 10 deg. before T.D.C. Exhaust plugs16 deg. before T.D.C. . Counterbalanced six throw. • Bore and strokeUnit capacity Total swept volumeReduction gear Rotation .. * .Airscrew shaft size Valve, type No. of valves/cylinderSupercharger Carburettor Magneto Plug positions Firing order .. Ignition timing .. Crankshaft type BEARINGS Main bearing diametersMain bearing areas Big-end diameterBig-end areas Centre, 5.45 sq. in. Ends and inters,5.12 sq. in. Fqrk rods, 3.10m.; plain rods, 3.773m.Fork rods, 6.28 sq. in. ; plain rods, 2.61 sq. in. 1.50m.Gudgeon diameterTotal gudgeon bearing area . . . . . . 6.83 sq. in.Rod/gudgeon bearing area 2.976 sq. in. Piston/gudgeon bearing area . . . . . . 3.854 sq. in.Con. rod length, centre to centre . . ' . . 10.65m. Ratio of con. rod length to stroke .. . . 1.614 :i^ = 3.228. Max. angularit)' of con.rod Cam base circle dia.Cam major axis length . . Valve lift .... 18 deg. 1.150m. I.53o8in. 0.570m. WEIGHT Power/weight ratio .. 0.941 Ib./b.h.p.Weight/sq. in. piston area 6.159 lb- Max. mean piston speed 3,025 ft./min.Weight of piston and rod ass'y/cyl. " .. .. 12.23 lb. Valve timing Inlet portthroat) area (valve ASPIRATION . . Inlet opens 24 deg. before T.D.C.;closes 44 deg. after B.D.C. Exhaust opens 64 deg. before C.D.C.;closes 4 deg. after T.D.C. Exhaust port area (valve 5-54 sq. in./cyl. throat) . . 4.12 sq. in./cyl.Piston area to inlet valve area ratio .. 5.103 : 1Piston area to exhaust valve area ratio .. 6.867 : !•Ratio of piston area to frontal area .. .. 0.298 : 1.Cylinder compression ratio 6:1. Max. internal compres-sion ratio of blower Impeller diametersM.S. gear ratio .. F.S. gear ratioEquivalent tip speeds Eye area of 1st impeller Rich mixture ratioWeak mixture ratio 5-3:1- 1st stage, 13.4m. ; 2nd stage, 11.3m5.84 : 1. 7-5S: 1.M.S. cruising, 1,071 ft./sec.; M.S max. power, 1,228 ft./sec.F.S. cruising, 1,391 ft./sec:; max. power, 1,594 ft./sec.56.1 sq. in. free, 40.5 sq. in., stricted by tail bearing support.11 : 1 by weight. 14 : 1 by weight. POWER 21 Ib./sq. in. F.S. re- Max, boost pressureMax. cruising boost pres- sureMax. b.h.p. Max. r.p.m.Cruise r.p.m. Max. b.m.e.p. Altitude to which 1 ata.manifold pressure is maintained Power/cu. in. sweptvolume Power/litre . . „„.., ...r.Power/sq. in. piston area 6.54 h.p. Power/sq. ft. frontal area 281 h.p.Power ratio/sq. in. piston area to sq. in. frontal' area .. .. ' .. 3.35 : 1. AUXILIARY DRIVES Auxiliary drive speeds (ratio relative to crankshaft)—Tachometer . . . . 0.250 : 1. Gearbox input . . 0.984 : 1 7 lb./sq. in. 2,220. 2,750- 2,400.286 lb./sq. in. 39,500ft. in F.S. gear. 0.992 h.p.60.5 h.p. MagnetoC.S.U Fuel pump Oil pumps Engine coolant pump . .Inter - cooler coolant pump StarterType of starter 0.50: 1. 0.82 : 1. 0.887 : 1. 0.984 : 1. 1-793 : i- 1.799 : i- 1 : 1. Coffman (Accessory drive faces:hydraulic pump, electric generator, air compressor,vacuum pump). combustion type L5. -V The very high output of the engine would not be pos- ^» sible without the two-speed two-stage supercharger which, ait.hough of greater capacity, seems to be smaller than that of the equivalent Merlin; nevertheless, a price of no less than 600 h.p. is paid in driving the supercharger and, even more amazing, this power is transmitted through relatively small friction clutches in the speed change unit. A driving frheel on the spring drive coupling at the rear of the crank- shaft meshes with a hollow layshaft in the change-speed unit, this layshaft housing a stationary piston and sliding '•:• cylinder assembly. Mounted on the layshaft are a series of clutch plates and driving rings on each side of a driving I member in which are pivoted six fly-weights ; the clutches on the crankshaft side of the central weights are for full supercharge drive (F.S.), whilst those on the impeller side <>! the weights are for moderate supercharge (M.S.), the respective clutches transmitting the drive through gears which mesh with pinions on the impeller shaft. When, for example, M.S. drive is in operation, the fly- Weights are held inclined rearwards by centrifugal force k t>; engage the clutch plates of the M.S. gear, and, as thei'S. clutches are disengaged and doing no work th,e driving gears can both be in constant mesh with the impeller pinions. Automatic Blower Gear Change If the aircraft climbs into an altitude range where F.S. gear is required, the change of speed is effected automatic- ally by a selector mechanism which actuates a piston valve so that oil delivered by the special pump in the crankcase is directed to the appropriate side of the change-speed unit piston. The pressure exerted against the piston reacts on the cylinder causing it to move, and by so doing, push the fly-weights away from the M.S. clutches towards the F.S. clutches; as the weights move beyond the neutral plane centrifugal force again takes hold and forces them to engage the F.S. clutches which thereupon transmit the drive through the high-speed F.S. gear. The automatic selector mechanism which effects the blower speed change comprises an aneroid capsule which operates a micro-switch to open a valve in the aircraft's air supply, and so pass compressed air to a ram on the end of the piston valve which directs the distribution of oil to the change-speed unit. However, the pilot is provided
Sign up to
Flight Digital Magazine
Flight Print Magazine
Airline Business Magazine
E-newsletters
RSS
Events
