Rolls Royce Merlin Engine Manual

Table of contents :
RRMerlinIIManual Ser. II_01
RRMerlinIIManual Ser. II_02
RRMerlinIIManual Ser. II_03
RRMerlinIIManual Ser. II_04
RRMerlinIIManual Ser. II_05

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PORT SIDE.

STARBOAR D SIDE.

REAR END.

FRO NT END. ROLLS-ROYCE " M ERLIN Jl".

AERO ENGINE

HANDBOOK FOR THE

INSTALLATION, RUNNING AND

MAINTENANCE OF

ROLLS--ROYCE "MERLIN"

AERO

ENGINES

SERIES II

(SUBJECT TO REVISION)

May, 1938 (Revi.rinted June, 1941)

Published by

AN D

ROLLS-ROYCE Llj\UTED DERBY; 14 & 15 CONDUIT STREET, LONDON

AMENDMEN1"'S FOR THE PRINTED BY ---· BEMROSE & SONS LTD. DERBY ANO LONDON

ROLLS-ROYCE "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 Air Intakes

Auxiliary Systems Controls ... Cooling System ... Electric Generator Electric Starting System Engine Mounting Exhaust System Fuel System Oil Filter in Installation Oil System Priming Arrangements Re-setting Boost P ressure (Progressive Type Regulator) Unpacking

4

15 15 14 II

15 15 7 15

7 Io

8 15 14 4

CHAPTER III.-STARTING, RUNNING UP AND GENERAL SERVICE .NOTES Coolant Pump Packing Gland and Grease in Syst em Correct Filling of Cooling System Drain Taps and Glycol Loss . .. Ensuring Sound Coolant Joints Ground Running Prior to Flight Inspection and Test of Cooling Circulation Running Starting ...

18 17

CHAPTER IV.--FLYING

~I

16 19 r6 19 19

18 19

CHAPTER V.-LUDRlCAN'fS, ETC., INSPECTION PERIODS AND FAULTS Faults Inspection Periods CHAPTER VI.-D l SMANTLING THE ENGINE TO UNITS ... v

30

CONTENTS.

L IST OF ILLUSTRATIONS.

P A GE

CHAPTIZR V ll.- D ESCRIPTION, DISMANTLING, INSPECTION AND ATTENTION OF ASSEMBL IES Air Compressor Drive (Rigbt-h and Cylinder Head) Air Intakes Airscrew Neduclion Gear Automatic Boost Regulator (Progressive Type) ..\uxiliary Drive or Oil Pump Drive for· Retractable Undercarriage Camshaft anci Rocker Mechanism Camshaft Inclined Drives Carburetter antl I nciuction System Connecting Rods Coolan t Pump Crankcase a nd Bearings Crankshaft Cylin der Block .and Liners D ecarbouizing Drive for Engine Speed Indicator Dynamo Drive and Couplings Electric !:itarting System Engine Controls Engine Oil Pipes Engin e Oil Pumps (Pre5sure and Scavenge) Exhaust :M anifolds Fuel Pumps Ignition Wiring and Magn etos I nduct ion Manifolds Oil R elief Valves an d Control for T wo-pitch Airscrew Pistons Priming and Volute Drain Pipes Proprietary Units Renewing a Cylinder Stud Tube Hemoval or Inspection of a Lesser Unit Servicing a Cylinder Block Starting Handle Superc harger Supercharger Drive Gears and Spri ng D rive Valves and Springs .. . \Vheelcase and Gears .. . CHAPTER VIII.- RE-ASSEMBLING E NGINE F R OM UNITS . Adjusting Valve Tappet Clearances .. . Magneto Timing Valve Timing

44 r59 67 177 ll9

us 44 132

83 167 133 136 152 I24 92 98

38 167 I72 t66 87 78 77 156 12 7 76 I 82 151

I82 137 ll4

55 62 1 52

95 186 r92 193 I9!

vi

LIST OF ILLUSTRATIONS PAGE

Front, Rear and Side Views of Engine Fig. I-Lubrication System .. . Flg. 2-Slinging the Engine . . . Fig. 3- Side View for Checking List Fig. 4-Side View for Checking List Fig. 5-Installa tion Dra wing ... Fig. 6 - Diagram of Typical Fue l Sys tem Fig. 7-Diagram of Ty pical Oil System Fig. 8-0il Filter Fig. 9-Engine Cooling System Fig. 10-Diagrammatic Pla n of Typical Cooling System Fig. I r-Control Positions and I3oost Gauge-Take-off Fig. 12-Control Positions and Boost Gauge-Climbing Fig. 13-Control Positions and Boost Gatige- :'.\:laximum Cruising Fig. I4_-Control Positions and Boost Gauge-Economical Cruising Fig. T 5- Lifting Reduction Gear Fig. I6-Extracting Dowels Fig. t7- Lifting Supercharger . .. Fig . 18-Lifting Cylinder Block Fig. r9-Cylinder Rig ... Fig. 20-Extracting Main Bearing Caps Fig. 21-Liftin g Crankshaft Fig. 22-Engine Controls Fig. 23-Controls . .. F ig. 24-Diagram of Carburetter Fig. 25- Carburetter Fig. 26--Supercharger System Fig. 27-Separating Superch a rger Casings Fig. 28-Vice Block Fig. 29-Supercharger . .. Fig. 30-Vice Blocks F ig . 31-Locating Pla te Fig. 32~elo~ 2,070. Climblng. With the airscrew pitch control changed . to the coarse setting, the mixture

the

control still at normal rich and the throttle fully opened to the automatic boost control of +61 lbs. per sq. inch (439 gr.fcm.1 ), climbing can proceed to the desired altitude. Having changed the airscrew pitch to the coarse setting, it may be found that the engine speed has fallen below 2,080 r.p.m., possibly causing detonation. Under these· conditions the angle of climb must be reduced to allOw the necessary increase in r.p.m. (2,o8o minimum).

c

.

CHAPTBR IV.-Fl.YING.

CHAPTER IV.- FLYJNG.

The mixture control should not be opened to the automatic weak position until boost pressure has fallen to ~i lbs. per sq. inch (158 gr./cm.1). The r.f.m. during the climb must not exceed 2,6oo, and the oil temperature should not normally exceed 90 C., but a peak temperature of 95° C. is permissible provided the duration does not exceed five minutes. . The coolant outlet temperature must not ~ceed uo° C.

For economical cruising, the mixture control must be in the automatic weak position, but the boost preslJW'e mllSt not exceed + 2t Ibs. per sq. inch ·(x58 gr./cm,I) or the r.p.m. ~.6oo. ~e limitations Oll the coolant and ~il temperatures are the same as for maximum cruising conditions.

+

23

Eoonomlcal Cruising.

WEAK OPEN

CLO.SEO

RICH

Boosr GAUGE

FIG. 12.-CLIMBING AND AL:IA>UT LEVEL FLIGHT.

The position of the variable pitch airscrew control in level filght must be that.: which gives a coarse pitch setting. ,At full throttle in level flight (a five minute limitation) the r.p.m. must not exceed 3,000 and the boost i;>ressure + 6t lbs. per sq. inch (439 gr../cm.1 ). The mixture control must be at the normal rich position and the temperature of the coolant outlet and oil inlet must not exceed those specified aboYe for climbing conditions. · · Maximum Crulelng. . Fqr continuous cruising, an engine speed of :a,6oo r.p.m. and a boost . /ressure of + 4l lbs. per sq. inch (3I6 gr./cm.•) must not be exceeded. The mixture control shoul . be in the normal rich position for a.11 boost pressures in excess of + :al lbs.

WEAK OPEN

BOOST GAUGE

LBS/D• (Gr/cml) "

FIG. 1.4.-:--EC()NOMICAL CRUISING.,

LBS/D• (Gr/cm•) "

Level Fllght.

CLOSED

Diving.

For diving operations the variable pitch airscrew controls should be in· the coarse pitch setting as for level flight.

Terminal Veloolty Diving.

When the ear~tter throttle lever is less than one-third of the full open position, the engine speed should· not exceed .3,000 r.p.m.

:Dive Bombing.

When the carburetter throttle lever is more than one-third of the full travel of the quadrant and with the maximum boost pressure of + 61 lbs. per sq. inch, the authorized maxim.um r.p.m. for level flighf may be exceeded in dives for.periods up to 20 secdnds, but the momentary maximum r.p.m. for terminal velocity diving must not exceed ·3,6oo r.p.m. _In addition to the above gerieral limiting conditions for the engine in terminal velocity dives, there may be overriding limitations in respect of the aircraft or airscrew. Flying in Formation.

As the engines are fitted with the progres&ve type regulator, the

boost i>ressnre will llicrease accordibg to opening i:noveriient of the pilot's throttle lever, but it is, nevertheless, essential for the leading pilot openillg to accommodate variations in the aircraft following.

It-is essential to allow the engine to idle for a short period before switching off (in order to cool the valves, etc.), otherwise it may continue to run under the in1luence of irregular and violent impulses which throw excessive stresses on the engine and .air frame. During this procedure the radiator shutters should be fully opened or the retractable radiator fully exposed. . . . ' Do not attempt to stop the engine by, opening the throttles at this stage, as the carburetter incorporates an accelerator pump which diSch.arges into eaoh choke on opening the throttle. 11 the procedure of tuniing .off the fuel is adopted, the ignition shoUld be switched oft at the first signs of irregular firing. ·

Stopping. .

BOOST GAUGE LBS/cf (Gr/cm1)

M

FIG. 13.-MAXIHUM CONTINUOUS CRUISING.

per sq. inch (I58 gr./cm.1 ). If tlu control lever is inad'IJerle'Htly left in llae weak positiMS, thB afttomatic · tOfltrol Tftll not re-adjust the mixture strmgth ~ M1'mal until the boost pressure "ceeds +3f lbs. per sq. inch (263·6 gr.fem."). With rich mixt~e setting, the consumption is approximately 25 per cent. greater than in the automatic weak aetting._ . ·

to allow a margin of throttle

To

CAMSHAfT. _

lo

_

__..i;

WHr.tLCAst.

lo

VARIABLC PITCH A11~. SCRf:W.

Low

PRCSSU"C TO

Rcoucr10N GcAR OIL JE:T5.

'SUCTION P IPE TO f lL TC:RS.

$CAV E:N~E: TO TNROTTLE'.S .

f ROM

PRESSURE. PUMP.

PUMP

HIGH PRESSURE OIL MAIN PRESSURE OIL

Low PRESSURE OIL SCAVENGE OIL FIG. 1.-LUBRICATION SYSTEM.

~~~~~:.:i. Low

To

PRESSURE TO

REDUCTION GEAR

AUXILIARIES

To VARIABLE ~~~Yk=~~

Low PRE.ssuRE. ro ROCKE.R MECHANISM

Low

FRE.ssuRE ro ROCKER ME.CHAN1$M.

PITCH AIRSCRE:W

OIL RELIEF VALVE~ SUf"f"L.Y FROM ~CAVE.NGE. PUMP.

To

To

PRe:ssuRt: GAUGE:.

AIRSCRE.W CONTROL

h'?t. .~';JF=~ol:::l:Jf-~-..:rHER MOME TE:R (OWNECTIONS.

OIL. HE.ATE.D THROTTLES.

Rt:LIE".f VALVE.$

RELIEF VALVE: DRAIN

.__,,._

HIGH PRESSURE

OIL SUPPLY

To

THROTTLE.S

flL TE.RS.

To io

To f uE.L

PuMP GLAND.

PRESSURE PUMP FROM TANK.

D1AGRAM

or

ScAYE:.NGE

r:BUES.

CHAPTER VII.-DEscRIPTION, D1s~iANTLING, INSPECTlOl'\ AND ATTENTION OF ASSEMBLIES.

8I

The terminals are fitted with insulated sleeves, Cr, containing spring pressed plungers to make electrical contact with the magneto distributor poi11ts, and protrude through separate bakelite plates numbered on their lower face according to each plug supplied, e.g., A.I.4 or B.E.6. "A" or "B" refers to the cylinder block, right- or left-hand side; I or E to the inlet or exhaust side plug. and 4 or 6 to the cylinder numbcT counting from the airscrcw end. The plate, therefore, must be replaced over the terminals with tl1e marking~ on lower face, the correct numbers registering according to the ECTtoN AND ATTENTION oF AssEMBLIEs.

dynamo drive shaft. At the rear end, keyed on a taper, another smaller gear meshes with the intermediate gear in m esh with the supercharger planet gear. Steel bushes in the casing support the floating phOS'J>hOr-bronze bushes, which have annular grooves and holes for lubrication. The hollow shaft is also drilled, being blanked off at its forward end by a disc . End movement of the gearshaft is limited by the forward bush flange, and an adjusting washer placed between the rear gear and bush face, a ring nut and lock washer securing the assembly.

... . _. ~

Lower Vertical A hollow vertical shaft, mounted in a ball bearing each end, has a bevel gear Drive. formed integral ·w ith its upper end to mesh with the lower side of the spring drive

gear. Towards this end, internal splines on another shaft engage the shaft, extending d0\1rnwards, inside, and splined to drive the coolant pump mounted co-axial on a bracket below. Also mou nted on the gearshaft are gears for engaging the fuel pump, J1, and the idler gear, Kr, the latter being mount ed in a bracket attached to the wheelcase for the purpose of driving the oil pumps, as explained. The coolant pump bracket i~ spigotcd and secured by four studs through its upper flange, and has an oil guard tube extending upwards, having a spiral outer groove and being secured at its lower flange by a ring nut and circlip. A ball bearing is ·presseur gcarshaft, sleeve and upper bearing race, r espectively, all being tightened together by the lower nut. An ahuninium skew gear is secured by splines and a ring nut to the spur g~rshaft, making the whole a combined unit for removal. The gearshaft has internal splines and an end locating bush engaging the bevel gearshaft. End location of the latter is effected by the upper ball bearing, meshing of the bevel gear being determined by the adjusting washer placed between the outer race and housing, which is retained in the casfog by a ring nut and circlip below. A ring nut and circlip retain at the upper end the serrated shaft which drives the coolant pump, the shaft · resting in a part spherical seating. Four studs at the wheelcase forward end secure a bracket in which is mounted an idler gear to mesh · with the gear referred to above. A hollow spindle, p inned in the bracket, forms a pivot for the gear, which has a phosphor-bronze bush inserted. Upper Vertical This comprises a vertical gearshaft having a bevel gear formed integral with Drive. its lower end, mounted in a ball bearing in t he casing, and having a roller bearing at its upper end. It meshes at the lower end with the upper side of a main bevel gear mounted on the spring drive shaft as explained, and bears another bevel gear at its upper end to mesh with the two inclined gears which drive the camshafts and their auxiliaries. A cover secured by studs encloses the whcclcasc top and bears the gland housing flanges, the drives being mounted below in the case. Driven by two keys near the lower end, a skew gear wheel of phosphor-

....' II

.'I ,,- - - .- ·:

/~:· ~ ~i:~~-. ~

I

- --:

/ i(:!K:_·~_/ ...

"

. -\

FIG. 44.-UPPER AND LOWER VERTICAL DRIVES.

97

98

CHAPTER V IL -

DESCRIPTION, DISMANTUN'G, b'SPECTION AND A TTENTCON OF ASSEMBLIES.

bronze is mounted and secured by a castellated nut and split pin above. This wheel meshes with the horizontal magnet o shaft as explained lat er. A distance piece separates the gear and ball !>earing, an adjusting washer being interposed between the bevel gear shoulder and beating lower face to determine meshing of bevel gears.

CHAPTER VI L -DESCRIPTIO N, D 1s :.\fANTLJKG, I NSl'ECTIOK AND A TTEKTION OF AssE.MBUEs.

safet y slipping clutch, P , which protects both hand and electric t urning gear against backfire. Dog teeth on the bendix shaft engage and t urn one of the smaller gears of the supercharger larger planet wheels, finally turning the central shaft, Q, which is coupled t o the crankshaft by splines, t he approximate gear ratio being 393 : I.

Each end locat ion of the shaft and gears is then effected by the ball bearing, which is retained below with a serrated ring nut of phosphor-bronze and a spring circlip. The upper bevel gear has an extension below it, a butting against an adjusting washer retained by a shoulder on the $haft. Splines at the upper end engage the gear which is secured by a castellated nut and tab washer above. The gear extension has an inner roller race formed integral to bear in a flanged outer race, pressed downwards, and then secured in the wheelcase by a circlip. The shaft is removable downwards as explained later.

Magneto Drive.

Meshing with the bronze· gear wheel described in "Upper Vertical Drive" , a hollow steel gearshaft is mounted hor izontally in a ball bearing each end and drives each magneto by internal splines at its centre, engaging t wo shafts. The magnetos are secured by studs t o vertical facings, one on eit her side of the drive centre line, and are coupled by hollow shafts having external serrations at t heir inner end, to engage the drive shaft, and internal serrati01ls at the outer end. This is formed with a flange, the serrations engaging a serrated coupling t apered and keyed on the magneto primary shaft and secured by a nut and tab washer. As there are eleven and twelve teeth at the inner and outer coupling ends, respectively, and the magneto shafts rotat e at one-and-a-half t imes crankshaft speed, a fine adjustment is formed for t iming purposes, t o allow setting within I error. Slight er rors in alignment are also cat ered for. The left hand ball journal is a push fit in the wheelcase, a flange in the latter limiting end movement one way and a shoulder on the gearshaft engaging the inner race. 0

At the other end, a similar shoulder is formed, and the outer race limited endwise by a flange retained by studs and adjust ed initially t o give t he required end clearance.

ELECTRIC STARTING SYSTEM

( Fi~

99

46).

A twelve-volt B.T.H. Starter Motor, Type C.A. 4125 , Form F .E .3, is fitted, a switch of the relay type being normally employed. The sequence of operation is as follows:Turning movement of t he armature shaft, N, is transmitted, by means of a splined coupling shaft, t o t he lower wheel of a compound planet. This rotat es in a fixed annulus, the upper wheel engaging and turning slowly in an opposite direction another annulus, the combination being kn own as a crypto gear, and giving in this case a reduction ratio of approximately 90:1. Th.is in turn drives a be~el gear, C, mounted thereon and incorporates a ratchet type free wheel, 0 , wl11ch allows a h~nd turmng gear to be operated without turning the motor. A lay shaft, and b~vel gea_r ~eshcd with that on the vertical shaft, is geared t o t he bendix form of engaging mechamsm. Tlns mcorporates also the FIG. 45.-MAGN ETO DRIVE.

roo

CHAPTER VIl.- DESCRtPTION, D1s:M:A~TLING, I~sPECTI0:'.11 AND ArTE~TION OF AssEMBLms.

The engaging mechanism is as follows:Tw-ning of the motor and gears causes a shaft, restrained rotationally by a light friction clutch, to move rearwards and engage a spr ing-pressed dog with the driven member. Continued movement of the drive then causes the forward movement of the shaft t o abut against a stop, thereby forming a solid drive, and causing the small friction clutch to slip. When the engine fires, t he engaged dog teeth t.hen overrun, causing withdrawal of engaging shaft. In the event of backfire, the dog teeth remain ·eugaged, and owing to the free wheel in the hand starter mechanism the gear would remain solid.. but for the protecting friction clutch which then slips. The four m ain assemblies arc described below.

Hand Starter Gear. This is secured as an assembly, to a facing on the right-hand side, by six nuts, A. (See Fig. 46.) It comprises a"bcvel gearshaft engaging at its inner end, the gear train in communication with the engine, and a free wheel as explained.

The outer end has a cross pin inserted for the purpose of engaging the start ing handle which can, therefore, only be rotated in one direction (clockwise), and so protects the operator against backfire. The shaft bears in a ball bearing at the gear end, and a phosphor-bronze bush at· the engagement end, in the co.sing. An adjusting washer between bearing and gear determines meshing of the latter, end loca.tion then being effected by the ball bearing, which is retained a t its outer race in the sted housing by a ring nut and circlip. The steel housing and casing are spigot e M}ll!NG E KGI!:\£ FRO:>! UNITS.

C HA.P TER VIIl.--RE-ASSEMBLING ENGINE FROM U NITS.

195

Two tinll.ng positions will be seen on the disc, namely, A6 M.A., and Br :.\-LA .. and either may be used , but each distributor must be set accordingly (see Figs. 36 and n 5). For example, if the A6 mark is used, the distributor pointer of each magneto must be set point ing to the A 6, or, alternat ively, at the Br contacts if the Bx posit ion is used. The ignition leads, of course, must not be changed about or timing will be useless. (See " Ignit ion Wires", Chapter VII.) It is assumed that the distributor covers are detached as shown in Fig. 37, and that valves have already been timed. Check that contact breaker points are ·012 inch (·305 m/ m) apart when in the f ully advanced position. Time magnetos as follows:! . Tµrn crankshaft in direction of arrow until one of the above markings, say A6 :\LA., r egisters with pointer mark. All valves m ust be closed in the A6 cylinder, since the engine must be on · its compression stroke. If this is not so, rota te the engine through 360° (one complete revolution). 2 . Fully advance the "B" side magneto contact breaker, and turn armature until the large d istributor pointer registers wit h contact marking A.E .6, and the contact brea ker points at L are just breaking. This can best be determined by use of a pilot lamp and battery in circuit with the contacts. 3. Make certain that t he correct side pointer is registering, as there are two ro'>vs o-f six leads and two main pointers. 4. Ensure that armature is not t urned, rotat e coupling, H, in stages until it can be engaged at both ends and magnet o pushed into position. This may necessitate several trials . 5. Secure magneto, using paper joint, three nuts and washers. 6. Without turning the engine, engage t he other side magneto, exactly as described before, except t hat th e distributor pointer will register with the A.I.6 contact . Secure magneto. 7. Replace each distributor cover and met al screen (observe note in " Wiring" section, Chapter VII ). Insert the. twelve terminals (it is assumed that the m arking plate is attached), and secure with two bolts for each magnet o. An alternative method of t iming is by use of a suit ably graduated plate fixed on t he red uction gear casing, using a point er on the airscrew shaft. The engine must then be timed according t o figures on page xi, taking care to avoid errors due to backlash between reduction gears. . Air Compressor.

Replace the air compressor (or the a uxiliaries ) after engaging its splined coupling with gear on rocker shaft and securing housing (four nuts) . Six nuts secm e the compressor. Secure rocker covers a fter inserting vellumoid washers.

Superc harger and Car bu rette r.

Insert rubber gland ring in central manifold and in supercharger bend, and screw up gland nuts a few threads only. Smear the rings with pure glycerine and insert short pipe with its earthing clip on top and towards the rear end of engine.

FIG. 115.- DIAGRAM MATIC LAYOUT OF TIMING GEAR.

r96

CHAPTEK VIIT.-·-R E-ASSEMBLDfG E~GI~E FROM UNITS.

CHAPTER VIII.-RE-ASSEMBLIKG ENGINE FROM U NITS.

- - - - - - - -- - - - - - - - - -- ----- -- .

---·· --- - - - - - - - - - - - -- - - - - - - - -- - - - --

Add paper joint and jointing compound to supercharger facing. Att ach the lift ing plate t o control bracket facing, as in Chapt er V I , and with crane lift assembly. Turn t he three planet gears so that the set ting gear HB.18152 can be engaged. Carefully slide the s upercharger assembly into position and secure with fifteen nuts. Screw up the t wo-gland nuts "vith pin spanner D.7102, and secure with lock plates. Add earthing connexion. Attach oil pipe to union on wht:elcase, and also to tail bearing of supercharger. l~clcase connexion, D , Fig. 39, at base of coolant pump and insert short pipe, connecting it with coolant connexion on supercharger casing. Screw up gland nuts. Replace earthing connexion.

Oil and Coolant Pipes.

Insert ends of main coolant pipe in gland joints at ~idc of cylinder block and in coolant purnp, and tighten gland nuts. Connect scavenge oil pipe from crankcase right-hand side union t o relief valve on supercharger, and secure clip. Insert end of main upper coolant pipe in gland of the other and screw up gland nut a few turns. Insert " Klingerit" joints (three each pipe), ensuring that they are in perfect condit ion. Attach ea~h pipe assembly with the restricted opening pointing t o the rear of engine. Assemble the right-hand pipe having its auxiliary connexion pointing rearwards on the righthand side of engine. Secure ea ch pipe assembly with ten nuts. Sccm e the main bracket to three studs on supercharger casing and couple up control rods t o boo:st regulator, each magneto, mixture control, accelerat or pump and main throttles, an(l cam control on progressive type regulator.

Controls.

Should the leng ths have been disturbed, see "Controls" section, Chapter VII. Replace coolant branch pipe and secure at its three connexions. Attach hook of crane to lifting eye and suppor t weight of gear in position for re-assembly. Smear the joint faces with jointing compound and the roller bearings with vaseline. Reduction Gear.

Insert dr ive coupling and carefully slide unit into position, engaging t he coupling splines and oil tube for airscrew pitch control. Carefully t ap the two dowels (at lower end) into the crankcase a nd fi nally secure with all nuts and bolts. Replace plug for lifting eye and lock wit h washer.

197

Should aut hority be obta ined to intercha nge a reduction gear assembly from one engine to another, the following points should be observed:! . The original rear roller bearing races must be used and extract ed from the crankcase as explained in that section. 2. The gear must then be assembled temporarily on its new engine, without the locating dowels, ~nd a blue test made to determine such a posit ion of the casing, that the gear teeth bedding is correct. 3. Having determined this position it may be found that the dowel holes are not in register. They will then require to he reamed out a nd new oversize dowels must be fitted. Priming and Volute Drain Pipes.

Secure the priming pipe assembly, one to each side manifold. The lefthand one bears the main priming connexion and the right-hand one the volute drain connexion. Confirm that all joints arc clear at the holes, that atomizers and holes are clean. Connect up the "Pctrollex" pipe to bend on supercharger, and abo the flexible pipe (right-hand side) to carburetter and volute drain assembly. \Vhen the engine has been finally assembled at the works the following points are locked with plain wire, twisted, and in certain cases sealed. A special. spring wire clip locks the drain t ap at the coolant pump base. I. Two retaining bars for magnet o contact breaker (two seals each). 2. Boost contr ol nut s (one seal). 3. Boost control cut-out (soft wire and one seal). 4. Oil relief valves (three sealc;). 5. Scavenge oil r elief valves (one seal) . 6. T op variable pitch airscrew union and hexagon plug on forward end o[ crnnkcase. 7. Forward oil jct on reduction gear casing (right-hand side). 8. Timing plug. Crankcase fonvard end. 9. Two magneto arms (two screws ~n each) . 10. Volute drain pipe union (each end). II. "Petroflex" priming pipe union (each end ). 12. Retaining screws for carburetter chokes (two). r3. Supercharger securing nuts (four wires , eight nuts). 14. Plug for fuel pump r elief valve. r5. Two oil filter covers (two screws and one cap nut for each).

Lock Wires.

It should also be confirmed that the two earthing wires have been fitted, one connecting the short extension pipe with supercharger, and the other connecting the coolant pump with short coolant pipe to carburetter. It is important that the cut-out hole, 0 , Fig. 34, is quite clear and that the valve movement is not prevented due to ingress of paint or jointing compound.

SUPPLEMENT TO

"MERLIN II" HANDBOOK FOR

Series III, IV & X E,ngines This supplement has been issued for the purpose of indicating the main differences between engines of the above series as compared \vith Series II Engines. Therefore, except where an assembly has been extensively altered or is additional (e.g. twospeed supercharger), attention is called only to the parts of the assembly which differ from those included in the Series II Handbook. This applies also to "Fits and Clearances". vv11cn so authorized, however, original "Merlin II" Engines may be modified to incorporate certain of the changes indicated as applying to later series.

LIST OF ILLUSTRATIONS. PAGE

Fig. Fig. Fig. Fig. Fig. Fig. Fig. Fig. Fig. Fig. Fig. Fig. Fig. Fig. Fig: Fig. Fig. Fig.

116-Diagram of Oil Piping and Modified Relief Valves 117-0il Fittings used in "Universal" Airscrew Shaft 1.18-Boost Control showing Modified Arrangement ... 119-- Diagram showing ·working of Two-Speed Supercharger 120-Layout of Dynamo Drive Gearing 121-Diagram of Starter Systems 122-Connecting Rods showing Loose Bearing Shells 123- Airscrew Reduction Gear and Auxiliary Drives 124-Spring Drive ... 125-Two-Speed Supercharger 126-0perating Mechanism for Two-Speed Supercharger 127-Automatic Boost Control 128-Dynamo Drive 129-Drive for Starter Motor 130-Starter Engaging :Mechanism 131--Connecting Rods 132-Drive for Gun Turret Pump 133-Drive for R.A.E. Air Compressor

facing page 3 4 1l

facing f>age 12 14 facing page 15 17 I9

23 24 27 29 31 32 3f 36 38 39

November, 1939.

Revised and Reprinted June, i941.

5Ul'PJ.EMENT TO "MERLI:\

2

tr"

HANDBOOI{.

Leading Particulars of Engines.

Page x.

(SERIES III & IV.) l\faximum take-off conditions...

Weight of engine as a.lreaia mctcr of piston

Diameter of piston stem ...

5

23 · 02 22·985 =-·- 22·96 •904 ·906i · 905

1 ·750 1 · 750

Ins.

m/ m .

1 ·375/o = 34·95 I ·

·ooor'ii~

374 = 34 ' 9

·006

M.::

. 15

·085

·025

·006

· 15

·OOI

·025

·004

.I

·00.1

·025

·005

• 1 25

·075

•OO ·OJ

}'ooot = -·015 ·oor! •04

} · ooo

m/m.

Ins.

•ooo

FIG. 127 .- A UTOMATIC BOOST CONTROL.

·01-

1·374-fo- 34· 924

6

Dore o f connecting rod jaw

· 25of

Diamet er of pin

· 250 · 249 ·247

* Piston la pped

into cy linder liner.

(,. 365 =- - 6· 35 6 · 325

=- -6 ·275

·254

' 2 45

6 ·45

... 6· 225

}:::t= I

•025 '09

SUPPLEMENT TO "MERLIN

II"

SUPPLEJ.l.f:ENT TO ''MERLIN

HANDBOOK.

11"

31

HANDBOOK

Page 76.

* Automatic Boost Regulator-Series X Engines (Fig. 127) LIST OF FITS AND CLEARANCES. Ref. No. -

15

Description.

-- --··}3ore of bush in casing cover Diameter of aneroid spindle

I

.Din1ensions, new. Permissible worn dimensions. I Ins. m/m. I lns. . m/m. '594i

I5' !05

. 593£ ·593

r5·08 r5·06

-- = ---

- ---

·592 16

Diameter of boost contr:ol camshaft

17

Bore of bush in rocker arm Diameter of bolt

r8

...

Bore of rocker arm J)iamcter of floating bush

!9

Bore of locating bush Diameter of aneroid housing

7·965 '3 1 3! = - -·. 312i} 7·935 · 31 rt 7·91 = - -. 31I 7·9 · r88~ • 187! . 187

-. 186! -

I ·662

Ins.

I ·oooi _ ·oz I ~O:Zf- -«>7-

i} I

clearance.

Ins.

m/m.

Page 95.

* Dynamo Drive and Couplings-Series X Engines (Fig. 128) ·005

LIST OF FITS AND CLEARANCES.

. 125

Ref.I ~o.

·316!= 8·04 ·3°7!= 7·81

FIG. 128.-DYNAMO DRIVE.

Description.

- - - - - - - - ·-

···

! Dimensio11s, new.

----·· -1l· -

Ins.

\~~

J ·002 !

·025 =

·005

i

. 125 I6

·065

Bore o( front wheelcase bush

· 191 = 4·85 · 183~= 4 ·66

~ ·ooo~ ~ ·or5 ) ·002

•004

7·95

·3r5!-• 8·015

7·935 7·91 --7·9

. 308!~ 7·835

42·215 = --42·165 41 ·985

}~~ ·002

·876

•004

'I

18

·05

Bore of rear floating bush Pia.mete r of intermediate shaft

1·670 ;=42·42 r ·643 = 4l ·73

}~~ ·Oll

·18 ·28

•or7

Ins.

IPermissible worn clearance.

m/m. '

Ins.

m / m.

i j

' } ·OOif

I

j

- ~·,

•005

·002!

I

Bore of rear wheelca.se bush

•05

·025

m/ m.

. ·751{- 19·09 ·751 ·~ r9·075 ·749l 19·03

Clearance, new·

dimensions. Ins. m/m.

I Diameter of floating bush

= ---

Permissible worn

• I

4·735

: r; - - -

r ·65r

• Refer

4·79 = - -- 4·765 1·75 =----

. 312t •JII! = . 31I

1 ·660 1 ·653

! I

--m/m.

Diameter: of floating bush

--

·313

·588}=14·955

IPermissible worn

r5·035

___..

Bore of bushes

·598 = I5' I9

Clearance, new.

•43 I9

41 ·935

Bore of front floating bush

::;;!=:::::~ I

I

·75ot

... I -:-75~ gea·~·1

·879} = 22·335 •125

19-065 = r9·05

. I

·748! = r9·01 ·748 19·0

I ·625t 15·89 ... i --:-: - - ! ·625 15·875

I 20

I

I

Di:i~~~icr of intermediate gea~. I

to page 75 for remaining dimensions.

22 ·25

·6 23 t=.12.·8.~5

·623

·620 =I5 ·75

i

·065

I I

r5·825

Backlash between gears- inter- I mediate gear shaft and super· charger gearshaft ... ·--1

Refer to page 93 for remaining dimensions.

·005

I

I

*

·04

•006

·015

I

• 15

.

- ·- - 1 ·orz

. 125

SUPPLEMENT 1'0 "MERI.IN

II"

HANDBOOK.

·-·---- - - --··

..

SUPPLEMENT TO "MERLIN

- - -----

Page

II" HANDBOOK.

33

III .

. Drive for Starter Motor-(Compound Epicyclic Gear) (Fig.129) LIST OF· FITS AND CLEARANCES. Ref j ~__o_. _ _ __

IDimensions new

Description _________

1

28

1

I

·

Ins.

m/m.

·719f

r8·27

=---

·718i

18·255

Dore of lower planet cage bush ... _ _ Dia.meter of gear shaft

29

Permissible worn Clearance new Permissible worn 1_______,__d_im_e_ns_i_on_s_.__ _ _ _ _ _ _ _ _ _ c_le_a_r_an_c_e_.~

...

...

·7r7i= 18·23 ·717l 18·22

Bore of bush in upper planet cage I

.

·626 __

= ---

'

·625

r5·875

Bore of bush in upper planet cage

i j .

m/m.

·721i=18·33

1

m/m.

Ins. } ·OOI

·002

·628! = 15·965

l:.~

- ~~

·620! = 15·76

) ·002t

·714!=18·155

Ins..

m/m.

•025

·05

15·9

Diameter of gear shaft

30

Ins.

=

·004 =

•IO

•004! =

. Il5

=

·125

·065

•9.53/ir 24•22 - ·953,Jrr - =-24·21 --

Diameter of lower planet cage ·952 24 · 18 shank ... ... ... . .. - = - -··951! 31

Bore of bevel gear lower bush

...

Diameter of upper planet cage shank ... ... ... . .. 32 *End float between upper planet,

lower planet and gear shaft 33 FIG. 129.-DRIVE FOR STARTER MOTOR..

...

Backlash between any pair of gears in epicyclic train... . ..

• Adjustable by washer.

24•17

. 1·406! 1 •405!:

35·72 35•695

1·401!=35·59

·001 = ·025 } ·003 ·003

-·005

·075

=

-·125

=

·405 I

•004

-·016-

•015 =

·38

•020 =

·sc

•10

j

34

SU PPLEMENT TO "MERLI N

If"

SUPPLEMENT TO "MERLIN

HANDBOOK.

JI"

HANDBOOK.

35

Page nz.

Starter Engaging Mechanism-Series X Engines {Fig. 130) LIST OF FITS AND CLEARANCES.

Ref.] Xu.

l

Description.

-i-----Bure of uush in gear Dia.meter of outer sleeve•..

2

Bore oI ouler sleeve hush

I

[ ·7lh£

44' 55 =---·-1·78r} 41·245

r·780

3

4

Bore of clutch spring housing

j

·626

·625 I •624

Dia.meter of outer 8lcove ...

[ Bore of starter .u332 to D. 11342 D.2056

No. 40362

D. 1 roor D.8722 F .86284 D. 11002 E.33091 D.10939 D. rrooo

40023 40026 40037 40024 2708 400:.u 40025

to

403]'2 32152

TITLE.

I

)Adjusting Washer Stud-Double Banjo Connection on Relief Valve Sheat h Kut,, Lock 'Was her- ,, Joint Washer·- ,, Distance Piece-,, Joint 'Washer- ,, Banjo Bolt-,, Locking Plate- ,,

SPECIAL BANJO FITTING AT BOTTOM OF DUAL DRIVE UNIT. See Foundation Diagram B .l. D.10967 D.5594 D.7224 E. 14748

4003 1 4011 8 4rn24 32044

Adaptor

...

Joint Washer Banjo Bolt Joint Washer

2

. D.7222 D.7223 K. 1807 K.45o5

4 T '21''2

41193 1724 1732

Locking Plate Distance Piece Cheei;e-heacl Screw (3 BA}

Grover Washer (3 BA) ...

l

3

SECTION "B"

SUB-SECTION B.3

B.

F'I TTING DIA.GRAM.

"""'O ftT1 '""

A

"'tYPE

MERLIN III EN GINES. · Nos. 2907 to 5605 I NCLUSIVE. Nos. 7163 to 7307 I NCLUSIVE. MERLIN IV ENGINES. Nos. 6243 to 6341 INCLUSIVE. MERLIN X ENGINES.

OF°

FITTING TWO - PITCH DE HAVILLAND BRACKET TYPE AIRSCREW 5000 SIZE, WITH VACUUM PUMP ONLY, TO ENGINES AS RECEIVED FROM STORES.

LIST OF PARTS REQUIRED TO COMPLETE THE FITTING OF A TWO - PITCH DE HAVILLAND BRACKET TYPE AIRSCREW AND VACUUM PUMP, TO MERLIN III, IV, AND X ENGINES AS RECEIVED FROM STORES. No.

D.10974 D.7303 D.8716 D.10938 D.2056 D.IIOOI D.8722 F .8(>284 D.II002 E.33091 D.10939 D.lIOOO

R:aa•. No.

41210 40062 32152 40023 40026 40037 40024 2708 40022 40025

·

T ITLJt.

Arrangement of Dual Drive Unit. Arrangement of Manual Control to Oil Cock. Oil · h Cli ps an d Uruon . F'i tt.mgs. Oil Pipe Pipe lf Comp1ete wit

C~AMGC •

WIU CUOl..0.

~o. OFF.

OL ~SSUR( l 50

L.&~.

P£1l fA ~NGK,

{ ......

l

-{U-

~N U.lb

SOtf1iC\. 10 P!U)T

FOR THO· Pll'M •1R!ICUW. ~H

ARR'l Ml D.130!>.

MERLIN m ENGIN E N'l''L907 To 5605 INCLUSIVE. MER LIN N ENGIN E N'J7163 To7307 INCLUSIVE . ME RLI N X E NGINE N'l16Z.4~ To6~41 INCLUSIVE.. TWO PITCH DE HAVILLANO B RACKET TYPE AIRSCRE.W ANO DUAL DRIVE. UNIT WITH VACUU M PUMP.

DIA.Gl2AM Nf 5. 3.

SPECIAL BANJO FITTING AT BOTTOM OF DUAL DRIVE UNIT. See Foundation Diagram B.1. A.M. .PIECE

Ko.

D.ro967 D.5594 D.7224 E.r4748 D.7222 D.7223 K.1807 K.4505

l

D.6405 D.6401 .E.9240 E.368n K.4410 K.46o2 . E.26190 E.33175 D.3576

I

D .3577

I I I l I

I

3

0. 10141.

I

R>:F. No .

40031 4on8 4ro24 32044 41212 4n93 1724 r732

T1T1.1-;.

Adaptor ... Joint Washer Banjo Bolt J oint Washer Locking Plate Distance Piece Cheese-head Screw (3 BA) Grover Washer (3 BA) ...

l'\o.

OFF.

I I I

2 l I

I I

MANUAL CONTROL.

Double Banjo Connection on Relief Valve ... StudSheath NutLock WasherJoint WasherDistance PieceJoint WasherBanjo BoltLocking Plate-

30702 30704 30710 30706 30708

...

Bracket Lever (complete with llall Joint) Bushes Spindle Plain Washer Split Pin ... Nut Seal in Spindle Control Tube End Pieces If ordering, quote Ref. No. 40c53 for Installation Pipes, etc.

30

eLA.0£. Pf'YCM

6.R~tKE.T

'2.0* Jtt.HC.(

\ C N UT o .1C1l9. B. ~~lA.NCE. Plt.C!.

(1) Remove Cap Nut and Sheath from the Airscrew Shaft. See that Distance Piece B is in mouth of Airscrew Shaft, leaving Oil Passage Open. (2) See that the First Stage of Relief Valve U is in place. Break seal and remove Plate from Two-way Oil Cock Lever Z . Fit Control Rod L with Crankcase Bracket and Lever for Manual Control of Oil Supply. See Arrgt. No. D.7303. (3) Remove Cap Nuts from Crankcase Banjo A and Relief Valve G, and couple up outside Oil Pipes:(a) Relief Valve to Crankcase F. (b) Relief Valve to Dual Drive Unit H. Fit Double Banjo Fitting Y on Relief Valve G. (4) Remove Cover R from Dual Drive Unit Q , and fit Vacuum Pump. Change bottom Plug J r to small Banjo Fitting. Sec Arrgt. No. D.10974. (5) Retain t he long Housing E and " Gits" Oil Seal. (6) Fit De Havilland Bracket Type Airscrew on to splines of Airscrcw Shaft, taking care that the Piston No. is P.5340-5.

PIECE

AI R''$LE ~NJO CONNEC~IOM

(OtiU: QJ.l»&

· ·--..Jll { $tAl'"" •'511CJ\lt'. t'.! jTAGf

FITTING VARIABLE PITCH ROTOL INTERNAL CYLINDER AIRSCREW, WITH VACUUM PUMP AND ROTOL CONSTANT SPEED UNIT, TO ENG INES AS RECEIVED FROM STORES.

-

Y

o ·~m.

Of:' 8 Et.JEF

/mv1. Awo gEeLACE

r.v

j P'=\JG. o 1oss1 -.l'Co ''"'')(Ell \ s.lli.4l.~

!.L -.~~~=::~===::;;--­

:t

See Foundation Diagram B .1 and Fitting Diagram B .5. (1} 1{emove Cap Nut and Sheath from Airscrew Shaft. (2) Remove Locking Wire D and Reta ining Nut C from mouth of J\irscrcw Shaft, to change Distance Piece B to Cover Br and Seal Ring. Replace :.Tut and \Vire, taking great care to make a perfect oil-tigh t joint on the taper of Front Support and spigot face of Cover. (3) Remove the First Stage·of Relief Valve and replace b y Plug and Washer U . Break seal on Two-way Oil Cock Z and remove Plate. Ope n Cock by moving Lever to the Rearward position. Replace Plate to lock Lever in the new position, lock with wire and seal.

(4) Remove Cap :'Juts from Crankcase Banjo A and Relief Valve G, and couple up outside Oil Pipes:-(a) Relief Valve to Dual Drive Cnit W . (b)_ Relief Va lve to Crankcase V. Fit Double Banjo Fitting Y on Relief V,13400/ 1, f{C., ~~la~

{1

OJ'~. ··· 2

.. .

Clipa,{1

SJfuF

1

pq,a, de., and

SECTION "C"

SUB-SECTION C.6

MERLIN III ENGINES.

No. 5607 ONWARDS.

·MERLIN X ENGINES.

No. 6343 ONWARDS.

FITTING DIAGt2AM.

DIAGRAM NfC6.

FITTING VARIABLE PITCH ROTOL EXTERNAL CYLINDER AIRSCREW, 35° RANGE, WITH VACUUM PUMP AND ROTOL CONSTANT SPEED UNIT, TO ENGINES AS DELIVERED FROM STORES.

See Foundation Diagram C.1 and Fitting Diagram C.6. (1) Remove Cap Nut and Sheath from the Airscrew Shaft.

(2) See that Plug U is in place of First Stage of Relief Valve, and that the Two-way Oil Cock Z is locked and sealed with the Lever in the Open or Rearward position. (3) Remove Covers R and S from Dual Drive Unit Q. Fit Vacuum Pump and Rotol Constant Speed Unit with Quill Shaft I. Change bottom Plug JI to large Banjo Fitting. See Atrgt. No. D.n636. (4) Remove Cap Nuts from Crankcase Banjos A and Ar, and Relief Valve G ---couple up outside

Oil Pipes:(a) Composite Pipe-Relief Valve to Dual Drive Cnit WI. .*(b) Two Pipes-Constant Speed Cnit to Crankcase, VI and V2. Fit Single Banjo Fitting Y on Relief Valve G. (5) H.etain Short Housing Er with the ''.Cits" Oil Seal. Change the Dummy Distance Piece Lr on the De-icing Pipe, for a short Feed Pipe to Airscrew L3, using the adjustment provided to clear the Airscrcw Slinger Ring. (6) Fit the Airscrew Hub on to the splines of Airscrew Shaft and secure with Kut. Inset the Inner Tube T2 down the bore of Shaft, and carefully screw down to. the shoulder. Follow up with the outer tube T3 also pressed down to a sho.ulder. Fit Piston and Cylinder. Care must be ta.ken to produce perfect oil-tight joints on the tube assembly.

"'Two-aided Oil Pipes have been allocated to MERLIN Ill ENGINES ONLY, and Single-aided Pipes to MERLIN X ENGINES ONLY.

54

•

gywp ppl!T!Cl!t, •TH pus, pej

. '*f§Q

ll!O ¥5lp

WIT!( ipp.

MEl2LIN

m ENGINE Nl·56Q7

MERLIN X

ONWl\QOS.

ENGIN~

Nl6343 ONWARDS. VARIABLE PllCH QOTOL E')(TERNAL · CYLIND£12 All2SCl2E.'N ANO OU"L OQIVE UNll WITH VACUUM PUMP AND ~OL CON&TANT SPEED

LIST . OF PARTS REQUIRED. TO COMPLETE THE FITTING OF A . VARIABLE PITCH ROTOL EXTERNAL CYLINDER AIRSCREW, 35° RANGE, WITH VACUUM PUMP AND ROTOL CONSTANT SPEED UNIT, TO MERLIN III AND X ENGINES AS RECEIVED FROM STORES . PI BCE

No. •RA.1988 •RA.1g65 A.54906 A.54631 . D.12088

A.M. RaP. No.

A.M•. RKF. Pl:scx No. No. G.54708 D.13404 D .2056

No. . TlTLB.

011'P.

Inner Tube-Airscrew Sh8ft Ou* Tube-Air8Cl'8W Shaft .. . 1 Be.njo Bolt-Constant Speed Unit 2 Joint Washer... ... 4 Oil Pipe} Co11sta.nt Speed Unit to {1 !)il .Pipe Cra11kcaae. I (Comp~ with Clip1, Comiections and Fittinga.) Oil Pipe} Complete with Clipe, Con- I 1 Oil Pipe nections and Union Fittings. l t Bracket-Oil Pipes ... .. . t Cover-Oil Pipe .13403

No. ori.

. Tin.is. Inner Tube-.AiraCl:ew Shaft Outer .Tubct-Airlcrew Shaft;

%

Joint Washer

4

••• ··• ••• ••• Oil Constant Speed Unit Oil Pip; · · Cm.xalr.c:a.ee. (Complete with Cipa, Connectlona

.

Oil Pipe l Complete with Clipt, Co11.Oil Pipe f nectiona and Union Fittings.

{I

Joint Wuher--Cover

••• x

...

E.3a4+.

31889

D.2035

32110

E.33091

2708

.A.5o86o

40083

No. Tln.:a:. Onr. Setecrew---Ccm::r 2 Lockplate--Settlcrew ••• •.• I Stud-Single Ba.a. o Comiec:t.ion OD

'Relief

Vatve ...

Distance Piece- ., Looking Plate- ., Banjo llolt- ., Joint Waaher- ., Banjo :Bolt

. ..

...

I I I

·" .. ...

I

.,.

2. . ..

I

... · ••• 2 2703 Joint Waaher ... E.49487 401e>8 Qaill ~tSpeed Unit l •RA.4777 D&-icingFeed Pipe to Slinger Ring 1 •RA.4776 Diatance Piece-D~.ic.ing Feed Pipe I

E.27490

I I

.. • · •. .

.J%I,ja

E.40366 32122

1

Bracket-Oil Pipes ... ... Cover-()il Pipe Connection...

R:a:r. No•. ·

D.1340.. D.20.56

to{t

:E>iJ>e}

PIBCB No. G.54708

I t

...

:Banjo Bolt-Conatu.t Speed Unit...

and Union Fittmp.)

...

rwa "'*

LIST OF PARTS REQUIRED TO COMPLETE TJIE FITTING OF A ROTOL EXTERNAL CYLINDER FEATHERING AIRSCREW. 75° RANGE, WITH ·VACUUM PUMP AND ROTOL CONSTANT SPEED UNIT, TO MERLIN III AND X ENGINES AS RECEIVED FROM STORES. · Plll:cB Rn. No. No. •RA.1582 •RA.1583 A.3490& A.5463t D.12o88 D.12o89

(5) Retain Short Housing Er or Long Housing E with the "Gits" Oil Seal (both are suitable). Change the D~1mmy Distance Piece Lr on the De-icing Pipe, for a short Feed 'Pipe to Airscrew L3, using the adjustment provided to clear the Airscrew Slinger Hing.

Ull9ll.

I

• 8uppll1d with Alraorew.

*Two-sided Oil Pipes have been allocated to MERLIN Ill ENGINES ONLY, and Slngle-slded Pipes to MERLIN X ENGINES ONLY.

.U., and Rt/. No. 40xo8 /or Qaill Shaft t1111iclt driwl Constant . . . · D.xos154/or D.xw:x>/r and ib araib, 1111til D.1'3400/x, ate.,~ avallab&. .

If ordlrlng, qliote Rll/. No. 40ISS fqr ltllt4llatlim Plpu, Spt«l Unit.

SribrtitD# PiP'

·

57

SECTION "C"

SUB-SECTION C.8

MERLIN X ENGINES.

FIU!NAM.

FITTING VARIABLE PITCH ROTOL EXTERNAL CYLINDER AIRSCREW, 35° RANGE, WITH VACUUM PUMP AND ROTOL CONSTANT SPEED UNIT, TO ENGINES AS DELIVERED· FROM STORES.

See Foundation Diagram D.l and Fitting Diagram D.5. (I) Remove Cap Kut and Sheath from the Airscrcw Shaft. (2) Remove Covers R and S from Dual Drive Unit Q.

Fit Vacirnm Pump and Rotol Constant Speed Unit with Quill Shaft I. (3)

J~cmove

Cap Nuts from Crankcase P,anjos A and Ar. Couple up outside Oil Pipes, V5 and V6-Constant Speed Cnit to Crankcase.

t(4) Retain Short Housing El, or Long Housing E, with the "Gits'' Oil Seal. (Both arc suitable.) Change the Dummy Distance Piece Lr on the De-icing Pipe for a short Feed Pipe to Airscrew L3, using the adjustment provided to clear the Airscrcw Slinger H.ing. (5) Fit the Airscrew Hub on to the splines of Airscrcw Shaft and secure with Nut. Insert the Inner Tube Tz down the bore of Shaft and carefully screw down to the shoulder.. Follow up ·with the Outer Tube T3 also pressed down to a shoulder. Fit Piston and Cylinder. Care must be taken to produce perfect oil-tight joints on the tube assembly.

t Long Housing E has been allocated to Merlin VIII Engines for use with the Rotol Internal Cylinder Alrscrew, and t Short Housing Er to Merlin XII for use with any Airscrew EXCEPT the Roto' Internal Cylinder.

.LIST OF PARTS REQUIRED TO COMPLETE THE FITTING OF

A VARIABLE PITCH ROTOL EXTERNAL CYLINDER AIRSCREW. 35° RANGE, WITII VACUUM

P!BcB No.

·•RA.r:g88

·•RA.1965· A.549o6 A.54631 D.IJLfO D.XJLJX

D.i:3931 D.13932 D.13271 K.xo8

·K.4307 KB.29_S3 D.i:32t>g D.13272 E.49487

•RA.4777

•RA.4776

74

PUMP AND ROTOL CONSTANT

SPEED UNIT, TO MERLIN VIII AND XII ENGINES AS RECEIVED FROM STORES.

A.Y. Ru. No.

.

No.On.

Trn.B.

Inner Tube-Airscrew Shaft

•••

I I 2

... .

Outer Tube-Airscrew Shaft .•• Banjo Bolt~nstant fu>eed Unit Joint Washer ... ... ... Oil Pipe-Constant Speed Unit to Crankcase ... Oil Pipe-Constant Speed Unit to Crankase .•• Complete with Clips, Connections and Fittings.

Bracket

4 I y

...

I I l

Clip

B115h-aips

....

Bolt

Lock Nut Lock Washer Clip

•••

•••

•••

•••

.=~:J:-Cons~t sj;ed u.tlt Feed Pipe to Slinger fie.icing

Ring

·Distance Piece-De-icing F«d Pipe • Supplied with AINCl"ew. 7$

:r

.

... ...

.•.

J: I I I

r I

I

SECTION "D"

SUB-SECTION D.6

MERLIN VIII ENGINES.

Nos. 7501 to 11489 INCLUSIVE.

MERLIN XII ENGINES.

Nos. 11491 to 13689 INCLUS IVE.

flTI!NG DIACi~AM,

DIAGRAM N' D 6.

FITTING VARIABLE PITCH ROTOL EXTERNAL CYLINDER FEATHERING AIRSCREW, 75° RANGE, ·wITH VACUUM PUMP AND ROTOL CONSTANT SPEED UNIT, TO ENGINES AS RECEIVED FROM STORES. See Foundation Diagram D.1 and Fitting Diagram D.6. (I} Remove Cap )Iut and Sheath from the Airscrew Shaft.

(2) Remove Covers R and S from the Dual Drive "Cnit Q . Fit Vacuum Pump and Rotol Constant Speed Unit with Quill Shaft I. (3) Remove Cap Nuts from the Crankcase Ban jo A and A r. Couple up outside Oil Pipes V5 and V6---Constant Speed Unit to Crankcase. (4} Retain Short Housing Er, or Long Housing E, with the "Gits" Oil Seal. (Both arc suitablr..) Change the D ummy Dista nce Piece LI on the D e-icing Pipe for a Short F eed Pipe to Airscrew L3, using the adjustment provided to clear the Airscrew Slinger Ring. (S) Fit the Airscrew Hub on to t he splines of Airscrew Shaft and sccurr. with Nut. Insert the Inner Tube T 4 down the bore of the Shaft and carefully screw do"W'Tl to the shoulder, Follow up with the Outer Tube Ts also pressed do"'-n to a. shoulder. Fit Piston and Cylinder. .care must be taken t o produce perfect oil-tight joints on the tube assembly,

/

lfllt.... l'l 11ir1 flll1U9I 9L •1IQLlt M"'

MERLIN 1llI ENG!N~ NP 7501 m I 148' !~CWSNE, MEQLlN m ENGINE N' llA91 TO 1'3689 1i..icLus1vE. fEA.THERING VARIABLE PITCH RQIOL EXTERNAL CYLINDER All(SrnEw ANO 1..!!!11... O~L Ot2!VE UNIT WlTH VACUUM PUMP ANO gQTOL CON5TN-IT SPEEO UNIT.

LIST OF PARTS REQUIRED· TO COMPLETE THE. FITTING OF· A .ROTOL EXTERNAL CYLINDER FEATHERING AIRSCREW, 75° . RANGE, WITH VACUUM PUMP AND ROTOL CONSTANT SPEED UNIT, TO MERLIN VIII AND XII ENGINES AS RECEIVED FROM A.H. STORES. Tm.B.

Plsc.s No, lbnr, No.

Inner Tube-Ainlcrew Shaft ,. • OUter Tube-Airscrew Shaft ·

•RA.i:58z •RA.i:583 A.54906 A.54631

Banjo Bolt-Constant Speed Unit ... Joint Washer .. . .

Oil Pipe-Constant Speed Unit to Crankcase Oil Pipe-Constant Speed Unit to Crankcase COD1plet.e with Clips, Connections and Fittings. Bracket .. . . .. . . . · ., . •.. . .. .. . ... . Clip

D.:XJX40

D,x3x41 D.i:3931 D.i:393z D.x327I K.i:o8 IL~307

Bush~P!!

su

KB,2953 41458 D.:13269 . D.:13272

E.49487

·•RA.4m *RA,4n6

40108

Bolt Lock Nut Lock Washer Clip ... Busb--Clip .. ; . . . . •. . .. . Quill Shaft-Constant Speed Unit ... De-icing Feed Pipe to Slinger Ring ·Distance Piece-De-icing Feed Pipe • Supplled wllh Alreorew.

7'I

No, On, I

2

4 I

l I l

x :x I I I J: I

EIIIIN~

SECTION "D"

D!AGDAM.

SUB-SECTION D.7

MERLIN VIII ENGINES.

Nos. 7501 to 11489 INCLUSIVE.

MERLIN XII ENGINES.

Nos. 11491 to 13689 INCLUSIVE.

FITTING DE HAVILLAND FEATHERING HYDROMATIC AIRSCREW WITH VACUUM PUMP AND DE HAVILLAND HYDROMATIC CONSTANT SPEED UNIT, TO ENGINES AS RECEIVED FROM STORES. See Foundation Diagram D.l and Fitting Diagram D.7.

-

(r) Remove Cap Nut and Sheath from the Airscrew Shaft. (2) Remove Cover R and S from the Dual Drive Unit Q. Fit Vacuum Pump and De Havilland Hydromatic Constant Speed Unit with Quill Shaft I. Change Top Plug J on Dual Drive Housing to Large Banjo Fitting. See Arrangement No.

D.u745.

SM llCH

LIST OF PARTS REQUIRED TO COMPLETE

THE

-

Yll.W

.

!11 g!pte !!f ~·

011'G~AM

Nf 0 7.

FITTING OF

. A VARIABLE PITCH DE HAVILLAND HYDROMATIC FEATHERING· AIRSCREW WITH· VACUUM PUMP AND DE HAVILLAND

up outside Oil Pipes:Composite Pipe W3. Starter Drive to bottom of Dual Drive Unit. Composite Pipe F3 to Crankcase Banjo A. Pipe X3. Top of Dual Drive Unit to Crankcase Banjo Ar.

. HYDROMATIC CONSTANT SPEED UNIT TO MERLIN VIII AND .XII ENGINES AS RECEIVED FROM STORES.

A.?4.

(6) Fit the Airscrew Barrel and Blade Assembly on to Airscrew Shaft. Insert the outer of two Internal Tubes TJ down the bore of Shaft before tightening the Alrscrew Shaft Nut. Press down to the shoulder. Follow up with the Inner Tube TG which is pinned to the Airscrew Valve Body. See that the "Gaco" Oil Seal is on the Inner Tube. Screw down to the face of Outer Tube, making a perfect oil-tight joint with t he Washer T8, between the Outer Tube and the Valve Body. The Inner Tube is screwed with a LEFT HAND thread. Assemble the remainder of Airscrew.

·a-·

.

Rllll'. No.

(5) See that Short Housing Er is fitted, complete with "Gits" Oil Seal. tFit the Slinger Ring Shield Ez on the front of Reduction Gear when required. Change the Dummy Distance Piece Lr on the De-icing Pipe for a Short Feed Pipe to Airscrew L4. using the adjustment provided to clear the A.irscrew Slinger Ring.

t On some installations the-shape-of.Front Cowling Plate forms a ehleld for Slinger Ring, so separate ftttlng Is NOT required.

MEJ?LIN l!lI ENGINE N!750l T0 11489 INCLUSIVE. MERLIN JlI ENGINE N~ll491 TO U669 INCLUSIVE.

DE HA\llUAND HYDl?OMATIC [E:ATHEQ!NG AIR5C12EW ANO DUAL DRl\JE UNIT WITH VACUUM PUMP ANQ HYWQMATIC CONSTANT SJ:£EQ UNIT.

(3) Remove Cap Nuts from Crankcase Banjos A and Ar. Take off outside Oil Pipe W2 from Starter Drive to bottom of Dual Drive Housing. (4) Couple (a) (b) (c)

lOfM

Trn'..Ji:.

Joint Washer ... Outer Tube-Airscrew Shaft · Inner Tube-Airscrew Shaft ..• Gaco Oil Seal . . •• Banjo Bolt-Dual Drive Joint Washer-Dual Drive ... Quill Sha.ft..-Const~t Speed Unit ... ... •.. Composite Oil Pipe, Starter Drive to Dual Drive Oil Pipe-Dual Drive Unit to Crankcase Banjo A Oil Pipe-Composite Pipe to Crankc~ Banjo A1

N'o. I I

....

D.n:ooz· D.u623 D.10751 D.n643 D.u6.p: D.m57r KB.2725 K.4307 K.4506 *P.30314

*P.30265-:aA ·

Clip

l'.

I

:r 2 I I I

....

:I

I

Rubber Bush .•• .. • Bracket.-:.compoaite Pipe Clip-Composite Pipe ...

:I :I

...

Rubber Bush ... Bolt Lock Nut Grover Wash.er... .•• •.• ••• ••• De-icing· Feed Pipe to 'Slinger Ring ... Distance Piece-Assembly De-icing Feed Pipe

• Supplied wlih Alreorew. 79

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PRESSURE OIL SUPPLY

D.10353 A OIL RELAY FOR OPERATING GE.AR CHANGE MECHANISM ON TWO SPEED SUPERCHARGER

II

I

Il Ill

Ill

OIL RELIEF VALVES FIG. 116.-DIAGRAM OF OIL PIPING AND MODIFIED RELIEF VALVES.

z A. Inlet for Scavenge Oil.

LOW GEAR A1. Clutch Engagement Springs. Az . Stop P egs for Ball Outer Race.

B . Outlet for Scavenge Oil. C. Two-Way Control Tap (to Pilot). D. Oil Relay Piston. E. Control Lever for Two-way Tap. F. Cam for Operating Low Gear. G. Camshaft Operating Lever. H. Cam R oller and Arm for Low Gear Operation .

J.

Selector For k (Low Gear).

I