Notebook

MGouldAG1605203-160708-08.pdf

Title

Notebook

Description

Contains notes and diagrams on fuel tanks, control settings, aircraft engine systems, ignition, cooling systems, layout of Merlin and other flight data.

Creator

Coverage

Language

Type

Format

Multipage notebook

Rights

This content is available under a CC BY-NC 4.0 International license (Creative Commons Attribution-NonCommercial 4.0). It has been published ‘as is’ and may contain inaccuracies or culturally inappropriate references that do not necessarily reflect the official policy or position of the University of Lincoln or the International Bomber Command Centre. For more information, visit https://creativecommons.org/licenses/by-nc/4.0/ and https://ibccdigitalarchive.lincoln.ac.uk/omeka/legal.

Contributor

Identifier

MGouldAG1605203-160708-08

Transcription

[cover]

[page break]

[inverted]

[table]

[calculations]

[/inverted]

[page break]

Oil Corrections. – [unreadable] Pumps – Fuel Pumps – Curved Pipe – Pressure Relief. Valve Unit [symbol] VP A/S lat.
[unreadable] Chamber [symbol] Reduction Gear sprogs.
Tail Bearing S.C. P. [unreadable] bearing in Steel Bearing not BB. [unreadable].

[diagram]

[page break]

[diagram]

[page break]

[underlined] Control Settings [/underlined]. 30° above horizontal = fully closed. 21 1/2 degrees below horizontal = fully open.
Recommended Procedure.
(1) Screw out Control Shaft stop screw.
(2) With B side magneto fully advanced and the 3 pin centres in line set control rod to correct length and shorten by 1/2 a turn. (This gives the required toggle action and produces a 3° retard at full throttle position).
(3) Repeat on A. side.
(4) With B Magneto fully retarded and pilots' throttle lever 30° above horizontal set control rod to correct length and connect up.
(5) Repeat on A side. [underlined] Mags [/underlined]

[page break]

[diagram]

ON MERLIN III BOTH MAGS FIRE AT 45° BTDC (FULLY ADVANCED

ON MERLIN X (MOD) XX TO 65, THE [underlined] PORT [/underlined] MAG FIRES 50° BTDC + STARBOARD 45° BTDC (FULLY ADVANCED IN BOTH CASES)

[page break]

AI is on exhaust where A6 is compression.
Mag Cross Drive rotates towards engine.

[underlined] SERRATED COUPLING [/UNDERLINED]

[diagram]

[symbol] II SERRATIONS
[symbol] ANGLE BETWEEN TWO ADJACENT
= 360/11 = 32.7°

[symbol] 12 SERRATIONS
[symbol] ANGLE BETWEEN TWO ADJACENT SERRATIONS
=360/12 = 30°
A VERNIER ADJUSTMENT OF [underlined] 1.8 ° [/underlined] (I.E. 2/3 (32.7° – 30°) IS PROVIDED

[diagrams]

CORRECT

EARLY. TO ADJUST. TURN THE SERRATED COUPLING BACKWARD THE NECESSARY NUMBER OF SERRATIONS THEN TURN MAG & SC BACK UNTIL IT MESHES.
LATE, TO ADJUST, [underlined] FORWARD [/underlined] AS ABOVE

[page break]

[inverted]

(5) Repeat operations 2 + 3 + 4 for the other mag and then check both mags for synchronisation.
(6) Firstly [underlined] remove the insulations from the primary pick-up tongue and completely assemble both magnetos [underlined] with care. [/underlined]
[underlined] Ignition timing sequence Merlin X (Mod) XX to 65 [/underlined]
The same as before, but with following Exceptions:-
The crankshaft is turned until the mark A6 E MA on the turning ring is coinciding [underlined] exactly [/underlined] with the pointer, and the port magneto is offered up and checked, as before, the the C/S. is turned [underlined] 5° [/underlined] in normal direction of R. until the mark A6 IMA is [underlined] exactly [/underlined] on pointer, and the starboard magneto is offered up, and checked. No synch check is necessary.

[/inverted]

[page break]

[underlined] Relay Piston Lever. [/underlined]

With relay piston fully forward pilot throttle lever 30° above horizontal & starboard differential lever 5° back from the vertical, set rod to correct length & connect up.
(alternative method for Merlin 3 – XX rod pin centres to 2 9/16 ".) On Merlin XII differential lever 7° back from vertical (rod pin centres 2 1/2 ". [unreadable]
Merlin XX – 45 differential lever 13° back from vertical. (alternative method – rod pin centres 2 9/16 ").
Throttle Curved Rod.
(1) Screw out Slow Running stop screw and close butterfly throttles fully in the bore (2) Screw in slow running stop screw to just touch stop.
(3) Insert a 20/000 feeler between

[page break]

[inverted]

screw + stop with the relay piston fully forward & pilot lever 30° above horizontal and connect up moved rod.
(4) Screw in stop screw to just touch stop. (Butterflies 6/000 open in bore at slow running).
[underlined] Change over lock. [/underlined]
With pilots [unreadable] 30° above horizontal and change over lever horizontal to 5° [underlined] above [/underlined] horizontal, connect rod with pinch bolt at the bottom.
[underlined] Progressive Com. [/underlined] III
(1) Set pilots' lever 21 1/2° below horizontal. (2) Insert a 30/000 between com cap & case, press whole assembly & correct rod. (3) With relay piston fully forward & pilots lever 21 1/2° below horizontal set control shaft stop screw. Merlin XII XV – 45 pilot

[/inverted]

[page break]

[underlined] Ignition Timing Sequence of Merlin III [/underlined]

(1.) Turn the crankshaft until the mark A6 MA on the timing ring is coinciding with [underlined] (exactly) [/underlined] the pointer, with [underlined] A6 [/underlined] cylinder on [underlined] compression stroke. [/underlined]
(2.) Set the Magneto as follows.
(1) Fully advance the contact breaker assembly (2) Check the C.B. points, and set to .012 + 1/000 Gap. (3) Insulate the primary pick-up tongue. (4) Set the distributor rotor so that, with the C.B. points just breaking (Comp & Battery) the main brush of the correct portion of the rotor is pointing to [underlined] A.6. [/underlined] segment
(3) Offer up the mag with the serrated coupling in any position, if it does not mesh, vary the coupling until it does
(4) Check timing, using a Comp & Battery and adjust, if necessary.

[page break]

[inverted]

lever 16° below horizontal, & [unreadable] lines on com & rocker com in line connect rod.
[underlined] Accelerator Pump [/underlined] Merlin III to XII
With Pilot lever 30° above horizontal, and ball end of pump lever in line with centre of linkage cover, set control rod to correct length & connect. Merlin XX – 45 (AXT 40 [unreadable])
Pilots lever 30° above horizontal connect rod to make pin & intermediate belt crank lever point vertically downwards.
[underlined] 2 Position Mixture Control. [/underlined]
Set back cover horizontal & connect up rod (Merlin XX & 45 all levers horizontal).

[/inverted]

[page break]

pointer, and repeat operations 3 & 5 for [underlined] B.I [/underlined] Cylinder.
(7.) Finally set all Inlet valve tappets to 0.010 clearance and all exhaust valve tappets to 0.020 clearance.
(N.B. If the firing order is followed, this operation can be carried out in two revolutions of the crankshaft.

Makers recommend setting C/S to 2° before A6IC to make up for Bank Sash. 1° = 16/000 or 1/16 approx on tuning ring

[underlined] Reduction Gear [/underlined] Spur Joyshaft type .477.1 Thrust [unreadable] & Rolls Fuel on A/S. Drive on front cover to [unreadable]esco & Cont[unreadable]tant speed unit.

[page break]

[underlined] TYPICAL MERLIN COOLING SYSTEM [/underlined]

[diagram]

[page break]

[underlined] Valve Timing Sequence – Merlin. [/underlined]

(1.) Disengage the serrated drive shafts.
(2.) Set one inlet tappet of [underlined] A6 & B1 [/underlined] Cylinders to 0.025[symbol] clearance.
(3) Insert a 5/000 Feeler in [underlined] A6 [/underlined] inlet tappet, and turn the "A" side camshaft [underlined] anti clock [/underlined] until the feeler is just nipped.
(4). Turn the crankshaft in normal D.O.R. until the mark [underlined] A6IC [/underlined] on the timing ring coinciding [underlined] exactly [/underlined] with the pointers.
(5). Engage the serrated drive shaft in its nearest setting, check the timing by use of the 5/000 feeler and adjust if necessary.
(6) Turn the crankshaft [underlined] 60° [/underlined] in normal D.O.R. so that the mark [underlined] B1IC [/underlined] is coinciding [underlined] exactly [/underlined] with the

[page break]

[inverted]

[underlined] Ducted Radi[unreadable] [/underlined]

[diagram]

LAYOUT OF "MERLIN" PRIMING & VOLUTE [underlined] DRAIN RETURN SYSTEM [/underlined] [symbol] = AN ATOMISER

[/inverted]

[page break]

The 11° drag causes a lag of16 1/2° on mags and 5 1/2° on valves.
[underlined] Wheel Case [/underlined]
[underlined] Upper Vertical Drive Shaft [/underlined] – (1) [unreadable] skew gear ([unreadable] bronze) to mag drive. 1 1/2 time engine speed. – (2) Cam drive.
1/2 engine speed.
Lower Vertical [unreadable] (1) Light alloy [unreadable] gear to fuel pumps (2) Mushroom pincer – [unreadable] pinion – 2 stoving pumps & 1 pressure gauge
(3) Self centring spindle to coolant gauge impellor.
Torqe [sic] Pinion on end of C/S drives train of Supercharger gears. 8.588-I-III
Impellor to 16 blades = 2.3-1
3. Slip Drives Phosphor Bronze [unreadable] engaged by plates. Generator Drive.
Bore plugs used for positioning when moulding.

[page break]

[inverted]

[underlined] Fuel Pumps [/underlined]
I Cogs Phosphor Bronze White [unreadable] 1 Cog Steel drive by interval [unreadable] to quill drive. 2-2 3/4 lb III relief valve, later [unreadable] 8-10 .
1 oil supply .
Hand Tuning Mesh

[/inverted]

[page break]

Rocker Shafts mounted in ends of Pedestal Brackets. Bottom of P. Bracket have tenons for location. End one has Y oil duct to com, will fit either bank. Oil also goes to rocker bearing through hollow shaft into rockers to com striking pod.
Oil sling fitted to outside of gears.
2 side gears rotate on bushes on extensions of rocker shaft.
[underlined] Whal Case [/underlined]
Spring drive shaft. Tested to 20° twist absorbs tortional vibrations through power stroke being 60° apart. From C/S to auxiliary drive. Dogs on Auxiliary pick up the drive from the C/S 11 degrees after spring drive take up, owing to log being 11° apart with 2° at the back.

[page break]

[blank page]

[page break]

[underlined] LAYOUT OF "MERLIN" [/underlined]

[diagram]

[page break]

[blank page]

[page break]

has 2 springs held by retaining plate secured by Phosphor Bronze split collects. Inlet valve guide mode of cast iron has same expansion of valve [unreadable]. valve seals made of aluminium bronze.
[underlined] Exhaust valves [/underlined] – austenitic S Steel hollow – filled with metallic sodium. Exhaust valve guides are Phosphor Bronze. Seals are made of Silicon Chromium Steel.
[underlined] Com Shaft [/underlined] held in 7 bearings hollow for oil inductor. Held in pedestal brackets. Nickel forged Steel drilled. Surface nitrated.
[underlined] Both cones rotate clockwise from rear [/underlined]
Front1 bearing light alloy, last 1 Phosphor bronze.

[page break]

[diagram]

[page break]

[underlined] Pin Boss & 1 below. [/underlined]
[underlined] The Cylinder Block. [/underlined]
The Monobloc type cast in one. it houses 6 cylinders in the form of inserted liners and form the combustion chambers and coolant jackets of those cylinders
Wet type [underlined] Cylinder liners [/underlined] fitted with 2 rubber synthetic washers and 1 aluminium alloy ring. 1 rubber washer round spigot fitting on bottom of liner below flange. Studs are surrounded by guard takes as protection against coolant. Two aluminium bronze spark plug adaptor per cylinder – 4 valves per cylinder 2 inlet 2 outlet
[underlined] Inlet Valves [/underlined] mode of austenitic SS steel, tip is coated with stellite stem nitrided, has fused onto the rim a ring of "Brightroy" all round face

[page break]

[diagram]

[page break]

Nickel Chrome Nitrided Hollow C/S.
180lb. fitted with adapter and timing ring. No 1 Journal no oil holes No 4 only 2 all the rest 3. All crank pins 2 oil holes.
Firing Stroke every 60° C/S rotation Con Rods Plain & York Forged Nickel Steel. Big End Bearings one Lead Bronze lined Steel Shell Small End for fully floating phosphor bronze. Cask. Gudgeon Pin made of air-hardening steel is fully floating. The Piston is a light alloy forging and the weight exclusive of rings is 3lbs (plus or minus a few droms), Fully skirted, concave crown. 3 Compression Rings of cast iron all having a 1° chamfer or appropriate 2 [unreadable] rings (Channel section) 1 above Gudgeon

[page break]

[blank page]

[page break]

Single Crankshaft 6 Throws.
1-6 2-5 3-4
7 Journals 6 Crank Pins

[diagram]

[underlined] Firing Order [/underlined]

[diagram]

"MERLIN" VALVE & IGNITION TIMING DIAGRAM.

[page break]

[blank page]

[page break]

Fuel Consumption (PTS/H.P./Hrs)
Max Takeoff .66/.73
Max Rich Cruising .58/.63
Max Econ. Cruising .54 max
Oil consumption. (PTS/Hrs) 6/18
Type of Fuel DTD 230 (87 Octone)
Type of Oil DTD [deleted] 109 [/deleted] 472
Net dry weight in lbs 1,375
Type of Coolant
Merlin 1-5 Echyline Glycol to DTD
344
CISE 12/95 Double Trock. Mags

[page break]

[blank page]

[page break]

Min Takeoff 2,080
Max Climb 2,600
Max Level Flight 3,000
Max Rich & Econ Cruising 2,600
Max Diving (more than 1/3 throttle) 3,600
Max Diving (less than 1/3 throttle) 3,000
B.H.P.
Rated at International R.P.M. 990
Minimum Rated Acceptance 950
Power at Max. Power Altitude 1,030
Max Takeoff 890
Boost.
Max Takeoff + 6.25
Max Climb & Level Flight +6.25
Max Rich Cruising + 4.5
Max Econ. Cruising +2.5
Altitude in feet
International 12,250
Max Power 16,250

[page break]

[printed calendar 1941 & 1942]

[page break]

[underlined] Merlin. [/underlined] Inline Upright Engine.
12 cylinder engine arranged 2 Banks of 6 on top of the crankcase with an angle of 60° between them.
Supercharged. Liquid Cooled.
Geared Engine. Compression Ratio 6-1
Bore 5.4" Stroke 6" Overall Capacity 1648 cubic inches or 27 litres
Main Oil Pressure (before increased capacity oil pumps was introduced)
60 to 75 lbs per [symbol]" (after) 75 to 95 lbs
Emergency Minimum (before) 45lb [symbol]" (after 60lbs [symbol]". Auxiliary Oil pressure 4 to 8lbs [symbol]" Emergency minimum of 2lbs [symbol]"
Performance Details Applicable to Type 2 - 3 - 4 - 5. Reduction Gear Ratio .477-1 R.P.M. Supercharge Gear Ratio 8.588-1
International 2,600
Max Takeoff 3,000

Collection

Citation

A Gould, “Notebook,” IBCC Digital Archive, accessed April 24, 2024, https://ibccdigitalarchive.lincoln.ac.uk/omeka/collections/document/28709.

Item Relations

This item has no relations.