Rolls Royce Merlin Engine Manual

182 Pages·57.745 MB·English

by  Rolls Royce

PORT SIDE.
STARBOARD SIDE.
REAR END.
FRONT END.
ROLLS-ROYCE "MERLIN Jl". AERO ENGINE
HANDBOOK
FOR THE
INSTALLATION, RUNNING AND
MAINTENANCE
OF
ROLLS--ROYCE
"MERLIN" AERO ENGINES
SERIES II
(SUBJECT TO REVISION)
May, 1938
(Revi.<ed and Ret>rinted June, 1941)
Published by
ROLLS-ROYCE Llj\UTED
DERBY;
AND 14 & 15 CONDUIT STREET, LONDON
AMENDMEN1"'S
FOR THE
- PRINTED BY ---· ROLLS-ROYCE
BEMROSE & SONS LTD.
DERBY ANO LONDON
"MERLIN" AERO ENGINE HANDBOOK
Series II. May, 1938
CoNT.ENTS.
CONTENTS
PAGI!
LIST OF ILLUSTRATIONS ... vii
LEADING PARTICULARS OF ENGINE x
CHAPTER I.-GENERAL DESCRIPTION
Lubrication System '2
CHAPTER II.-UNPACKING AND INSTALLATION 4
Air Intakes 15
Auxiliary Systems 15
Controls ... 14
Cooling System ... II
Electric Generator 15
Electric Starting System 15
Engine Mounting 7
Exhaust System 15
Fuel System 7
Oil Filter in Installation Io
Oil System 8
Priming Arrangements 15
Re-setting Boost Pressure (Progressive Type Regulator) 14
Unpacking 4
CHAPTER III.-STARTING, RUNNING UP AND GENERAL SERVICE .NOTES 16
Coolant Pump Packing Gland and Grease in System 19
Correct Filling of Cooling System r6
Drain Taps and Glycol Loss ... 19
Ensuring Sound Coolant Joints 19
Ground Running Prior to Flight 18
Inspection and Test of Cooling Circulation 19
Running 18
Starting ... 17
CHAPTER IV.--FLYING ~I
CHAPTER V.-LUDRlCAN'fS, ETC., INSPECTION PERIODS AND FAULTS
Faults
Inspection Periods
CHAPTER VI.-DlSMANTLING THE ENGINE TO UNITS ... 30
v
CONTENTS. LIST OF ILLUSTRATIONS.
PAGE
CHAPTIZR V ll.- DESCRIPTION, DISMANTLING, INSPECTION AND ATTENTION OF
ASSEMBLIES
Air Compressor Drive (Rigbt-hand Cylinder Head)
Air Intakes 44
Airscrew Neduclion Gear r59 LIST OF ILLUSTRATIONS
Automatic Boost Regulator (Progressive Type) 67
.. \uxiliary Drive or Oil Pump Drive for· Retractable Undercarriage 177
PAGE
Camshaft anci Rocker Mechanism ll9 Front, Rear and Side Views of Engine Frontispiece
Camshaft Inclined Drives us Fig. I-Lubrication System .. . 2, 3
Carburetter antl Inciuction System 44 Flg. 2-Slinging the Engine .. . 4
Connecting Rods 132 Fig. 3- Side View for Checking List 5
Coolant Pump 83 Fig. 4-Side View for Checking List 6
Crankcase and Bearings 167 Fig. 5-Installation Drawing ... 6, 7
Crankshaft 133 Fig. 6- Diagram of Typical Fuel System 8
Cylinder Block .and Liners 136 Fig. 7-Diagram of Typical Oil System 9
Decarbouizing 152 Fig. 8-0il Filter IO
Drive for Engine Speed Indicator I24 Fig. 9-Engine Cooling System I2
Dynamo Drive and Couplings 92 Fig. 10-Diagrammatic Plan of Typical Cooling System 13
Electric !:itarting System 98 Fig. Ir-Control Positions and I3oost Gauge-Take-off 2I
Engine Controls 38 Fig. 12-Control Positions and Boost Gauge-Climbing 22
Engine Oil Pipes 167 Fig. 13-Control Positions and Boost Gatige- :'.\:laximum Cruising 22
Engine Oil Pumps (Pre5sure and Scavenge) I72 Fig. I4_-Control Positions and Boost Gauge-Economical Cruising 23
Exhaust :Manifolds t66 Fig. T 5- Lifting Reduction Gear 31
Fuel Pumps 87 Fig. I6-Extracting Dowels 31
Ignition Wiring and Magnetos 78 Fig. t7- Lifting Supercharger ... 32
Induction Manifolds 77 Fig. 18-Lifting Cylinder Block 34
Oil Relief Valves and Control for Two-pitch Airscrew 156 Fig. r9-Cylinder Rig ... 34
Pistons 127 Fig. 20-Extracting Main Bearing Caps 35
Priming and Volute Drain Pipes 76 Fig. 21-Lifting Crankshaft 36
Proprietary Units I82 Fig. 22-Engine Controls 39
Renewing a Cylinder Stud Tube 151 Fig. 23-Controls ... 42
Hemoval or Inspection of a Lesser Unit I82 Fig. 24-Diagram of Carburetter 44, 45
Servicing a Cylinder Block 137 Fig. 25- Carburetter 48
Starting Handle ll4 Fig. 26--Supercharger System 55
Supercharger 55 Fig. 27-Separating Supercharger Casings 58
Supercharger Drive Gears and Spring Drive 62 Fig. 28-Vice Block 59
Valves and Springs .. . 152 Fig. 29-Supercharger ... 60
\Vheelcase and Gears .. . 95 Fig. 30-Vice Blocks 62
Fig. 31-Locating Plate 63
Fig. 32~<iupercharger Gears 64
CHAPTER VIII.- RE-ASSEMBLING ENGINE FROM UNITS. 186 Fig. 33-Diagram of Boost Regulator 68
Adjusting Valve Tappet Clearances ... r92 Fig. 34-Boost Regula.tor 73
Magneto Timing 193 Fig. 35-Ignition Terminals 78
Valve Timing I9! Fig. 36-Diagram of Ignition Leads 79
Fig. 37-1\fagneto, with Parts Removed 8I
Fig. 38-Withdrawing Magneto Coupling Mange 82
Fig. 39-Coolant Pump 84
Fig. 40-Fuel Pumps 88
Fig. 4r-Tool for Removing Drive Gear 89
Fig. 42-Fuel Pumps 90
vi vii
LIST OF ILLUSTRATIONS. -.....- -·---- LIST OF ILLUSTRATIONS.
PACE PAGE
Fig. 43- Dyna.mo Drive Gears. .. 93 Fig. 93- Withdra'!"ing Dearings from Housing I62
Fig. 44- Vertical Drives 97 Fig. 9-1-Removing Rear Roller l.face r63
Fig. 45-Tlfagneto Drive 99 Fig. 95-Pil()t Drift 163
Fig. 46-Layout o[ Starter Systems ... IOO, 10! Fig. 96-Asserubling Rear Roller Raco i64
Fig. 47-Vicc Blocks 103 Fig. 97-Rcpladng Forv:nrd Bearings on Airscrew Shaft 164
Fig. 48-Removal Tools ... ro4 Fig. 98-Removing Oil Filters ... 171
Fig. 49- Tool for Magneto Drive 105 Fig. 99-Extracting Tool for Roller Race 172
Fig. 50--Tools £or Hand Starler Gear IO] Fig. 100-0il Puntp!I 174
Fig. 51-Tools for Starter Gear 107 Fig. 101-Withdrawing Drive Gear 175
Fig. 52-Tool for Starter Layshaft 108 Fig. xo2-0il Pump Drive J78
Fig. 53-Starter Gears ... 109 Fig. 103-Vice Block 180
Fig. 54-Vicc Blocks JI4 Fig. 104-Vice Block 180
Fig. 55- Testing Slip-loading of Clutch 115 Fig. 105-Withdrawing Tool ·Jso
Fig. 56-Cai:nshaft Inclinecl Drive aud Toors Il6 Fig. 106-Vice Rlock 181
Fig. 57-Testing Daeklash II8 Fig. 107-·-Vice Block 181
Fig. 58-!fool for Removing Gearslrn.It n8 Fig. ro8-Startcr Motor 183
Fig. 59-Removing Bevel \Vheel l:Zl Fig. ro9--Electric Generator 184
Fig. 60--Removing Rocker Shaft l:Z2 Fig. 110--TiltiDg Cylinder Block 188
Fig. 61-Carnshaft and Rocker Mechanism .. . 123 Fig. J 1 r-Slipping Spanner 189
Pig. 62-Drive for Engine Speed Indicator .. . u5 Fig. 112-Cylinder Nut Template 189
Fig. 63-Tool !or Holding Gear 125 f'ig. 113-Securing Rockers (Temporarily) 191
Fig. 64-Pislou and Connecting Rods 128 Fig. 114 -Valve Tappet Arljnstmcnt ... 193
Fig. 65-Crankshaft aud Bearings r34 Fig. 115-La.yont of Timing Gear 194
Fig. 66-Extracting a Cylinder Liner 139
Fig. 67-Blocks for Setting Up Cylinder 140
Fig. 68-Depth Gauge ... 141
Fig. 69-Record of Cyliuder joint Faces 141
Fig. 70-Facc Cntting Tool J42
Fig. 71-Record of Cylinder Joint F:aces 143
Fig. 72-Lapping Tool ... 143
Fig. 73- Record of Cylinder Joint Faces 143
Fig. 74-Record of Cylinder Joint Faces 144
Fig. 75- Gauge Ior joint Ring 144
Fig. 76-Cap Gange 145
Fig. 77- Lapping Tool ... 145
Fig. 78-Rccorcl of Cylinder Joint Faces 145
Fig. 79-Record of Cylinder Joint Fa.ces .146
Fig. So-Record of Cylinder Joint Faces 146
Fig. 81-Pilot Tool 146
Fig. 82-Test Rig 147
Fig. 83-Cylinder aud Valves ... 148
Fig. 84- Withdrawing a Cylinder Tubo 151
Fig. 85-Replacing a Cylinder Tube ... 151
Fig. 86- Removing Valve Springs 153
Fig. 87-Inlet Valve Grinding Tool 155
Fig. 88-Lappini; Tool and Blucing Gauge ... 155
Fig. 89- Blue Test Block J56
Fig ..9 o-Oil Relief Valves 157
Fig. 9r-·Airscrew Reduction Gear r6o
Fig. 92-Removiug Airscrew Shaft from Bearings ... 161
ix
viii
LEADING PARTICULARS OF ENGINE. LEADING PARTICUf.ARS OF ENGINE.
LUBRICATION.
Type oil :Hritish Air :vlinistry Specification-D.T.D. 109
(mineral).
Oil consumption at maximum cruising conditions Io-l8 pints per hour (5·6 to 10·2 litres/hour).
Oil pressure-main Normal-Go lbs./sq. inch (4·218 kgs./cm.2).
Leading Particulars of Engine Emergency minimum-45 lbs./sq. inch (3·16
kgs./cm.2).
Oil prP.ssure-auxiliary Normal---6 lbs./sq. inch (422 gr./cm.1).
Emergency minimum-2 lbs./sq. inch {i. .p
GENERAL. Inlet temperature for take-off (minimum) 15g°rc../ cm.2).
Inlet temperature for climbing and level flight (maximum) 90°c.
Type Supercharged, geared, glycol cooled, 60° Vee.
Inlet temperature maximum (5 minutes emergency) 95•c.
Cylinders: :N'umber and arrangement. .. i2 cylinders in ~vo lkcylinder monoblocks.
Bore· and stroke 5·4 ins. by 6 ins. (137·16 rn/m x 152·4 m/m). CARBURATION.
Compression ratio 6·0 : I. Type fuel British Air Ministry Specification-D.T.D. 230
(87 octane).
Airscrew reduction gear: Maximum fuel demand 90 gallons per hour (409 litres/hour).
Type Spur layshaft. Type of carburetters Duplex {Rolls-Royce S. U.).
DRiarteicot ions of rotation 0A•4ir7s7c re; wI .s haft, anti-clockwise; crankshaft, Fce<l pressure supply 2 to 2f lbs./sq. inch (140 to r93 gr./cm.2).
clockwise when · viewed from the engine
forward end. . IGNITION.
International power rating 990 B.H.P. at 2,600 R.P.1\L at r2,250 feet
Number and type of magnetos Two B.T.H. CIS/E/12-S.
(r,004 C.V., 2,600 R.P.M., 3,734 metres).
Maximum power rating I,030 B.H.P. at 3,000 R.P.M. at 16,250 feet Number and type of .sparking plugs (per cylinder) Two K.L.G. RV. r4/4, or
(1,044 C.V., 3,000 R.P.!\I., 4,953 metres). Lodge R.A.-14,14.
Maximum take-off power 890 B.li.P. at 2.850 R.P.!\'l. at sea level ~fagneto timing (fully advanced) 45° B.T.D.C.
(902 C.V., 2,850 R.P.M.). Contact ureaker gap ... 0·012 inches (-305 m/m).
Rated boost pressure ... +6! lbs:/sq. inch (439 gm./cm.2). Sparking plug gap 0·0J2 ins. to 0·015 ins. (-305 m /m to ·38 m/m).
Maximum take-off conditions ... +6l lbs./sq. inch boost and 2,850 R.P.M. Firing order IA, 6B, 4A, 3B, 2A, 5H, 6A, 1B, 3A, 4B,
Minimum take off R.P.M. at + 6l lbs. per sq. inch boost 2,0(8403.9 gm./cm.2). 5A, zB.
VALVE TIMING.
:Maximum climbing conditions +ot lbs./sq. inch boost and 2,600 R.P.M.
(439 gm./cm.2). Valve tappet clearance for timing a.n(I cold running 0·020 inch (·51 m/m).
Maximum level flight ... +6t lbs.jsq. inch boost and 3,000 R.P.M.·
Inlet valve opens 3i0 B.T.D.C.
(439 gm./cm.2).
Maximum continuous cruising conditions (normal rich mixtures) ... +d lbs./sq. inch boost and 2,600 R.P.M. Tnlet valve closes 52° A.R.D.C.
(316 gm./cm.2). Exhaust valve opens 72° B.B.D.C.
Maximum economical cn1ising conditions (weak mixtures) +2! lbs./sq. inch boost and 2,600 RP.M. Exhaust valve closes '12!0 A.T.D.C.
(158 gm./cm.2).
Maximum diving, R.P.M. 3,600 (see page 23).
PARTICULARS OF COOLING.
Weight of engine, nett dry, including ignition system, with bonding
and screening, carburetters and induction systems, engine-driven Coolant ... Ethylene Glycol.
fuel pump, water outlet collector pipes, hand turning gear, super·
Maximum temperature at outlet 95°C. when cruising, 120°C. on climb.
charger with necessary pipe work and drives for accessories
mcorporatcd in engine, but excluding airscrew hub, exhaust
manifolds or stub pipes, air intakes, co111Jexions from water
outlets and water pump to radiator, oil and coolant 1,335 lbs. STARTING.
Cylinder numbering Airscrew. Type Hand turning gear and i2-volt electric motor.
IB IA
2B 2A
3B 3A
4B 4A
5B 5A
6B 6A
x xi
CHAPTER !.-GENERAL DESCRIPTION. I
CHAPTER I
General Description
This handbook is divided into eight chapters, arranged and tabulated to facilitate easy reference
without the necessity for ari index.
The sub-headings given under each clmpter (pages v and vi) should therefore be referred to.
As a detailed illustrnted description of each section of the engine is contained in Chapter VH,
a general outline only is given below.
The lubrication system is also included and embodies a general section of the engine.
The Rolls-I{oyce "Merlin II" engine is a twelve cylinder, supercharged, liquid cooled type,
employing Ethylene Glycol as a cooling medium. It has two blocks of six cylinders, mom1ted at 60°
to one another, at inclined upper faces on the cn.nkcasc.
A spur reduction gear is airanged at the forward end, to drive an airscrcw shaft (mounted above
the engine centre line) at 0·477 times engine speed.
Means are incorporated whereby a two-position pitch airscrew can be operated, using ma.in
uy
pressure engine oil controlled the pilot to move a piston in the hub assembly, or alternative
means when it is required to incorporate a constant speed unit. A fixed pitch airscrew may be
used if required.
a
A superchargtr, co-axial with the crankshaft, and at the rear end, has speed multiplying gear
to drive an impeller, for the purpose of obtaining a positive induction pipe pressure when required,
and maintaining it up to a given rated altitude.
This boost pressure is regulated automatically, within limits, by an aneroid controlled relay, the
w1it being mom1ted above the supercharger.
Below the latter, a twin choke carburetter is attached, to draw from an air intake at the lower
face, aneroid controlled jets providing mixture adjustment for varying altitude and booi:;t pressure.
Four overhead valves, two inlet and two exhaust, operate in each combustion space, six of which
are. formed in the block casting. Steel liners are spigotcd at their upper erid to form both a liquid and
combustion joint, the lower end of the block skiit housing a floating gland around each liner. Eacl1
monoblock assembly is secured to the crankcase by long studs.
Inclined shafts from the whcclcasc drive one overhead camshaft for each head, to operate four
rockers for each cylinder, one per valve.
2 CHAPTER !.-GENERAL DESCRIPTION.
A six-throw, balanced crankshaft, carried in seven main bearings, engages the re<luction gear,
forwards, and rearwards drives all the auxiliaries by a thin spring steel shaft allowing torsional
flexibility.
Forked connecting rods of marine type are used having aluminium pistons. floating small end
bushes and gudgeon pins.
Ignition is by two magnetos, each firing one of the two plugs in all twelve cylinders, the high
tension leads being protected, earthed and suitably directed by metal conduits.
Two starting means are provided, narhely, by hand turning gear or an electric motor which
operates through a reduction gear train incorporated in the wheelcase.
A centrifugal pump, vertically mounted and driven from the wheelcase lower end, circulates the
coolant. A single inlet connects ·with ipstallation, two deliveries supplying, one each cylinder block.
In addition to those drives which are essentially part of the engine, auxiliary drives are provided
for the use o.f electric generator, engine speed indicator, generator p~mp for operating retractable
undercarriage, high pressure air compressor and generator pump for gun turret control.
Duplex fuel pumps fonn a unit driven from the wheelcase left hand side, each pump being of
sufficient capacity to supply the maximum demands of the engine. ·
Lubrication System. Lubrication is by a gear type pressure pump, the system being of a
"dry sump" type, and two other gear pumps being employed to drain
the crankcase front and rear end, independently. They are all incorporated with the lower half
crankcase.
The system is illustrated diagrammatically in Fig. I.
The first stage is regulated to approximately r50 lbs. per sq. inch (10·54 kg./cm.2) for the purpose
of operating the two-pitch airscrew. The second stage is regulated to 60 to 70 lbs. per sq. inch (4·21 to
4·92 kg./cm.2), and supplies the main high pressure oil to the engine. Drilled passages in the crank
case convey oil-to a main gallery pipe ~upplying each of the seven main bearings having two holes
in the lower half.
The six big-end bearings are fed via oil holes in the crank webs supplied by main bearings Nos. 2, .
3, 5, and 6, Nos. 2 and 6 having annul~r grooves, and Kos. 3 and 5 part annular grooves, registering
with holes in the crank journals and providing uniform oil distribution.
The fuel pump bushes and gland are also fed from the high pressure system, the flow being
restricted by a small hole in the pressure oil pump.
The third stage is regulated between 4 and 8 lbs. per sq. inch (281 to 562 gr./cm.2) and supplies
the various auxiliaries such as camshaft and rockers, reduction gear, electric generator and super
charger drive gears, and impeller bearings. The camshaft drives and timing gears are lubricated by oil
which drains back to the crankcase through the camshaft drive housings. Oil also drains back via
tubes through which pass the cylinder holding down studs.
Provision is made at the high pressure main supply on the relief valve casing for fitting a ther
mometer and pressure gauge.
l l
Insert Spread "• ExM MerlinII 0022" Insert Spread"• ExM Merlinil 0023"