Gipsy major overhaul manual

OPERATION, MAINTENANCE AND OVERHAUL GIPSY MAJOR SERIES 10

This manual compiles with British Civil Airworthiness Requirements Section A, Chapter A6-2. The technical accuracy of this manual has been verified and is certified as correct.

CONTENTS AND LIST OF CHAPTERS

NOTE : A list of its contents and illustrations appears at the beginning of each chapter.

FRONTISPIECE
FOREWORD
INTRODUCTION
LEADING PARTICULARS
LUBRICATlNG OILS
OPERATING LIMITATIONS
GIPSY MAJOR MK. 8
TORQUE LOADING TABLE
CHAPTER
I.	Description of Engine.
II.	Lubrication.
Ill.	Carburation.
IV.	lgnition.
V.	Installation.
VI.a.	Operating Instructions.
VI.b.	Defect Diagnosis.
VI.c.	Storage and Anti-Corrosion Treatment.
V I.d.	Components containing asbestos.
VII.	Maintenance Schedule and Routine Servicing.
VIII.	Tools and Equipment.
IX.	Dismantling.
Xl.	Rectification and Salvage.
XII.	Reassembling.
XIII.	Testing after Overhaul.
XIV.	Table of Fits and Clearances.
XV.	BTH Magnetos.
XVI.	Rotax Electric Starter.
XVII.	K.L.G. Sparking Plugs.
XVIII.	Lodge Sparking Plugs.
XIX.	Hobson Carburettor.
XX.	Fuel Pump.
Accessory Manufacturers' Addresses.

LUBRICATING OIL FOR DE HAVILLAND GIPSY ENGINES

The Gipsy range of de Havilland piston engines is approved for operation in Arctic and Temperate conditions on lubricants complying with British Ministry of Supply Specification D.Eng.R.D.2472, and in Tropical conditions on lubricants complying with de Havi1land Specification DHE.227.

The appropriate grade of oil must be used according to the prevailing conditions and the following grades of oil, certified as complying with these requirements, are, until further notice, suitable for use in de Havilland Gipsy engines in appropriate climatic and operating conditions.

Conditions of Operation	"Arctic" (Below 0 deg. C.)	" Temperate " (0-30 deg. C.)	"Tropical" (Above 30 deg. C.)
Specification	D.Eng.R.D.2472.A/O	D.Eng.R.D.2472.8/O	deHavilland DHE.227
The following grades comply with the above specifications.
Esso Petroleum Co.	Esso Aviation Oil 80	Esso Aviation Oil 100	Esso Aviation Oil 120
Shell.:.Mex Ltd	Aeroshell 80	Aeroshell 100	Aeroshell 120
Regent Oil Co.	Caltex Aircraft Engine Oil 80	Caltex Aircraft Engine Oil 100	Caltex Aircraft Engine Oil 120
Vacuum Oil Co.	Mobiloil Aero, grey band	Mobiloil Aero, red band	Mobiloil Aero, green band
C. C. Wakefield & Co.	Castrolaero " A "	Castrolaero " B ''	Castrolaero " C "

The conditions of operation given above can, of course, act only as a general guide, for, as will be readily appreciated, the wide variations of temperature that may occur in one locality even during a single day would make impossible a literal application of the recom­ mendations. In general, however, if it is expected that the temperatures specified for the use of tropical or arctic grades of oil will be met at ground level during the normal course of opera ion of the aircraft at that particular time, then the appropriate grade of oil should be used.

OPERATING LIMITATIONS, PERFORMANCES AND FUEL CONSUMPTION

For oil pressures and minimum temperature, see Leading Particulars. Powers subject to a tolerance of minus 4 per cent.

With a fixed-pitch propeller it is not possible to obtain all these conditions but none of the operating limitations may be exceeded.

Gipsy Major 10, Mark 1-1, 1-IA, 1-3, l-3A, 1-7 and 1-7A (Based on Engine Technical Certificate No. SS, issue 6, 25-1-55)
Flying conditions	Time limitation	R.P.M.	Boost pressure in. Hg. cm. Hg.	Cyl. temp, deg. C.	Oil temp, deg. C. Oil grade* D. Eng. R.D.2472 B/O	B.H.P. at Sea Level	Fuel consumption (upper limit)
							Galls, per hr.	Litres per hr.
Maximum take-off Maximum emergency	-- 5 min.	2400 2550	Full Throttle	240	100	136/142 145	11¼ 11½	51,11 52,25
Climb Emergency cruise	60 min. --	-- 2400	Full Throttle	230	85	136/142	11¼	51,11
Maximum cruise	--	2300	Minus 1½ Minus 3,8	210	85	138	10	48,9
Maximum cruise, weak	--	2300	Minus 4 Minus 10,2	210	85	120 3750 ft. 1143 m.	8½	38,62
Maximum overspeed	20 sec.	2675	Full Throttle	--	--	--	--	--
Gipsy Major 10, Mark 2 and 2-1. (Based on Engine Technical Certificate No. 89, issue 7, 12-1-56)
Flying conditions	Time limitation	R.P.M.	Boost pressure in. Hg. cm. Hg.	Cyl. temp, deg. C.	Oil temp, deg. C. Oil grade* D. Eng. R.D.2472 B/O	B.H.P. at Sea Level	Fuel consumption (upper limit)
							Galls, per hr.	Litres per hr.
Maximum take-off Normal Emergency	5 min. 15 min.	2550	Full Throttle	255	100	139/145	11½	52,25
Minimum r.p.m. at maximum take-off boost pressure	--	2000	--	--	--	--	--	--
Maximum continuous	--	2400	Full Throttle	250	85	136/142	11¼	51,11
Maximum weak mixture	--	2300	Minus 4 Minus 10,2	230	85	120 3750 ft. 1143 m.	9	40,89
Maximum overspeed	20 sec.	2675	Full Throttle	--	--	--	--	--

For information regarding the use of lubricating oils see page vii.

GIPSY MAJOR M K.8

As the original Gipsy Major Mk. 8 engines (pre-mod. 1685) were fitted with Hoyt white­ metal bearings and all the Gipsy Major 10 Mk. 2 engines have the Vandervell main bearings, civil

approval of the Gipsy .M. ajor Mk. 8 was neither sought nor obtained.

With increasing numbers of Royal Air Force Gipsy Major Mk. 8 engines becoming available in the civil market, the Air Registration Board has agreed that this type of engine can be used in civil aircraft subject to the following provisos :-

1. The military log card or log book must be available.
2. Before the engine may be used, the operator must comply with the current requirements of Air Registration Board Notice to Licensed Aircraft Engineers No. 16.
3. On transfer of the engine from the Royal Air Force, a civil type log book must be raised and all relevant entries made in it. The log book may only be raised by the Inspection Department of an organisation approved for the overhaul of de Havilland Gipsy engines, or by a ‘ D’ Licence engineer in this category.
4. The engine type must be recorded in the log book as “Gipsy Major 10 Mk. 2” and the engine name plate must be altered to accord with this nomenclature.
5. The log book must be endorsed to the effect that only fixed-pitch propellers may be used on the Gipsy Major Mk. 8, or 10 Mk. 2, engines with Hoyt white-metal main bearings ; modification 1685 introduced Vandervell bearings to Gipsy Major Mk. 8 engines.

The instructions and information given in this handbook for the Gipsy Major 10 Mk. 2 are equally applicable to the Gipsy Major Mk. 8 having regard to· the modification standard of the engine.

When ordering spares for Gipsy Major Mk. 8 engines, operators must inform this Company of the engine number for which the parts are required, so that the correct parts may be supplied.

''''TORQUE LOADING TABLE

To assist overhaul and maintenance operators to ensure that correct loads are applied when tightening certain nuts on Gipsy Major Series 10 engines, the table set out below lists the respective torque loading values. These values are subject to threads being lubricated, and not being stiff to turn during any part of their travel ; they are not the loadings to be applied when the appropriate studs are being inserted. The table will be amended accordingly when appropriate torque loading values are issued for other components of the engine.

Nut Part No.	Descriplion	Torque Loading (lb. in.) and recommended tools
800-CN-1	Nut, Intermediate and Rear Main Bearing	500 to 600 MSW 208, TQ.S0A
800-CN-2	Nut, Front Main Bearing	300 to 400 MSW 207, TQ.S0A
N.372 or N.376	Nut, Rocker Bracket (pre-mod. 2197)	300 MSW 205. TQ.S0A
N.6542	Nut, Rocker Bracket (mods. 2197 or 2282)*	Tighten to 360, slacken completely and then retighten to 275. MS W 204, TQ.S0A
1900/3	Nut, Connecting Rod	180 to 270 MSW 204, TQ.50A
801/16B	Nut, Cylinder, Holding Down	350 to 400 mod. 2329 T79017 T79013 T86451

Cylinder Heads (mods. 2197 and 2282)

Modification 2197 introduces a redesigned cylinder head of L.35 (' Y' alloy) which provides for the attachment of the rocker bracket to the cylinder head with three studs and one bolt. The rocker platform provides better support by improved cylinder head webbing ; the valve rocker bracket supports the valve rocker cover thus dispensing with the stirrup bracket ; the cylinder head cooling is improved by additional finning in the vicinity of the exhaust port ; and 14 mm. sparking plug adapters replace the l 2 mm. type. When this modification is embodied, the / 2 mm. sparking "plug end fittings of unscreened, and screened ignition cables are replaced with end fittings suitable for use with the 14 mm. screened type sparking plugs.

As an alternative to the cylinder head mod. 2197, a cylinder head mod. 2282 is introduced incorporating 12 mm. plug adapters to permit the use of 12 mm. sparking plugs.

When assembling the rocker bracket to the cylinder head, it is important that all the rocker bracket attachment nuts are tightened in rotation with small torque increments until the final torque loading value is obtained.