Specifications from the official Sprite/Midget Workshop Manual, covering the 948 cc, 1098 cc, and Sprite Mk IV/Midget Mk III (1275 cc) specifications.
948 cc Engine
Engine
| Type | 9CG. |
| Number of cylinders | 4. |
| Bore | 2·478 in. (62·94 mm.). |
| Stroke | 3·00 in. (76·2 mm.). |
| Capacity | .. 57·87 cu. in. (948 c.c.). |
| Firing order | I, 3, 4, 2. |
| Compression ratio: High | 9 : I. |
| Low | 8·3 : I. |
| Capacity of combustion chamber (valves fitted) | 24·5 c.c. |
| Valve operation | Overhead, by push-rod. |
| Oversize bore: I st | .. ·010 in. (·254 mm.). |
| Max | .. ·040 in. (I ·016 mm.). |
| Torque (H.C.) | 52·8 lb. ft. (7·3 kg. m.) at 3,000 r.p.m. |
| Main journal diameter | 1·7505 to 1-7510 in. (44·46 to 44·47 mm.). |
| Minimum regrind diameter | 1·7105 in. (43·45 mm.). |
| Crankpin journal diameter | 1·6254 to 1·6259 in. (41·28 to 41·30 mm.). |
| Number and type | 3 shell type. |
| Material: Bottom half | Steel-backed, lead-indium-lined. |
| Top half | Steel-backed, lead-indium-lined. |
| Length | 1-1875 in. (30·16 mm.). |
| End-clearance | ·002 to ·003 in. (·051 to ·076 mm.). |
| End-thrust | . . Taken by thrust washers at centre main bearing. |
| Diametrical clearance | ·001 to ·0025 in. (·025 to ·063 mm.). |
| Undersizes | -·010 in., -·020 in., -·030 in., -·040 in. |
| Length between centres | 5·75 in. (14·605 cm.). |
| Material: Bottom half | Steel-backed, lead-indium-lined. |
| Top half | Steel-backed, lead-indium-lined. |
| Bearing side clearance | ·008 to ·012 in. (·203 to ·305 mm.). |
| Bearing diametrical clearance | ·001 to ·0025 in. (·025 to ·063 mm.). |
| Type | .. Flat crown, aluminium alloy, anodized. |
| Clearances: Bottom of skirt | ·0016 to ·0022 in. (·040 to ·056 mm.). |
| Top of skirt | ·0036 to ·0042 in. (·0914 to ·1067 mm.). |
| Oversizes | +010 in., +·020 in., +·030 in., +040 in. |
| Compression: Plain | Top ring. |
| Tapered | Second and third rings. |
| Width (plain) | ·069 to ·070 in. (l ·75 to l ·78 mm.). |
| Thickness | ·103 to ·109 in. (2·62 to 2·78 mm.). |
| Fitted gap | ·007 to ·012 in. (·178 to ·30 mm.). |
| Clearance in groove | ·0015 to ·0035 in. (·038 to ·089 mm.). |
| Oil control type | Slotted scraper. |
| Width | ·124 to ·125 in. (3·15 to 3·175 mm.). |
| Fitted gap | ·007 to ·012 in. (·178 to ·30 mm.). |
| Clearance in groove | ·0015 to ·0035 in. (·038 to ·089 mm.). |
| GENERAL DAT A-continued |
948 cc Engine
Gudgeonpin
| Type | Semi-floating. |
| Fit in piston | ·0001 to ·00035 in. (·0025 to ·009 mm.). |
| Fit in connecting rod | ·0001 to ·0006 in. (·0025 to ·015 mm.). |
| Diameter (outer) | ·6244 to ·6246 in. (15·86 to 15·865 mm.). |
| Seat angle: Inlet and exhaust | 45°. |
| Head diameter: Inlet | 1·151 to 1·156 in. (29·23 to 29·36 mm.). |
| Stem diameter: Inlet | ·2793 to ·2798 in. (7·094 to 7· 107 mm.). |
| Exhaust | ·2788 to ·2793 in. (7·081 to 7·094 mm.). |
| Valve lift | ·312 in. (7·925 mm.). |
| Valve stem to guide clearance: Inlet | ·0015 to ·0025 in. (·038 to ·063 mm.). |
| Exhaust | ·002 to ·003 in. (·051 to ·076 mm.). |
| Valve rocker clearance: Running (cold) | ·012 in. (·305 mm.); ·015 in. (·381 mm.) for com• |
| Valve rocker bush bore (reamed) | ·5630 to ·5635 in. (14·30 to 14·31 mm.). |
| Timing markings | Dimples on timing wheels. |
| Chain pitch and number of pitches | ¾in. (9·52 mm.). 52 pitches. |
| Inlet valve: Opens | 5° B.T.D.C. |
| Closes | 45° A.B.D.C. |
| Exhaust valve: Opens | 51° B.B.D.C. |
| Closes | 21° A.T.D.C. |
| Valve rocker clearance: timing check | ·021 in. (·74 mm.). |
| Length: Inlet and exhaust | 1·687 in. (42·86 mm.). |
| Diameter-inlet and exhaust: Outside | ·4695 to ·470 in. (11·92 to 11·94 mm.). |
| Inside | ·2813 to ·2818 in. (7·145 to 7·177 mm.). |
| Fitted height above head | Hin. (15·1 mm.). |
| Outer | 1·75 in. (44·45 mm.). |
| Fitted length: Inner | 1·179 in. (29·95 mm.). |
| Number of working coils: Inner | 6½. |
| Outer | 4½. |
| Pressure: Valve open: Inner | 30 lb. (13·6 kg.). |
| Outer | 88 lb. (39·9 kg.). |
| Valve closed: Inner | 18 lb. (8·17 kg.). |
| Outer | 52 lb. (23·6 kg.). |
| Type | Bucket. |
| Diameter | ·8120 in. (20·62 mm.). |
| Centre | .. l ·62275 to l ·62325 in. (41·218 to 41·231 mm.). |
| Rear | 1·3725 to 1·3735 in. (34·862 to 34·887 mm.). |
| End-float | ·003 to ·007 in. (·076 to ·178 mm.). |
| Bearing: number and type | 3. Steel-backed white metal. |
| Inside diameter (reamed in position): Front | 1·667 to 1·6675 in. (42·342 to 42·355 mm.). |
| Centre | 1·62425 to 1·62475 in. (41·256 to 41·369 mm.). |
| Rear | 1·3745 to l ·3750 in. (34·912 to 34·925 mm.). |
| Clearance | ·001 to ·002 in. (·025 to ·051 mm.). |
| GENERAL DATA-continued |
948 cc Engine
Engine Lubrication System
| Type | Eccentric rotor or vane type. |
| Relief pressure valve operates | 60 lb./sq. in. (4·2 kg./cm. 2). |
| Relief valve spring: Free length | 2·859 in. (72-63 mm.). |
| Fitted length | 2·156 in. (54·77 mm.). |
| Type | Full-flow. |
| Capacity | 1 pint (1·2 U.S. pints, ·57 litre). |
| Normal running | 30 to 60 lb./sq. in. (2-1 to 4·22 kg./cm. 2). |
| Idling (minimum) | IO to 25 lb./sq. in. (·7 to 1-7 kg./cm. 2). |
Fuel System
| Make and type | S.U. twin HS2 semi-downdraught. |
| Diameter | 1¼in. (31-75 mm.). |
| Jet | ·090 in. (2·29 mm.). |
| Needles | Standard V3. Rich V2. Weak GX. |
| Piston spring | Light blue. |
| Make and type | A.C. 'Y' type. Mechanical. |
| Delivery rate | 40 pints/hr. (48 U.S. pints/hr., 22·8 litres/hr.). |
| Delivery pressure | 1·5 to 2·5 lb./sq. in. (-105 to ·175 kg./cm. 2). |
| Type | .. Paper element. |
Cooling System
| Type | Pressurized radiator. Thermo-siphon, pump- and |
| Thermostat setting | 65 to 70° C. (149 to 158° F.). |
| Blow-off pressure | 7 lb./sq. in. (·49 kg./cm. 1). |
Ignition System
| Sparking plugs | Champion NS. |
| Size | 14mm. |
| Plug gap | ·024 to ·026 in. (·625 to ·660 mm.). |
| Coil | Lucas Type LA12. |
| Distributor | Lucas Type DM2P4. |
| Distributor contact points gap | ·014 to ·016 in. (·36 to ·40 mm.). |
| Static ignition setting: High compression | 4° B.T.D.C. |
| Low compression | 1° B.T.D.C. |
Clutch
| Type | Single dry plate. |
| Diameter | 6¼in. (16 cm.). |
| Facing material | Wound yarn. |
| Pressure springs | 6. |
| Colour | Yellow and dark green. |
| Damper springs | 4. |
| Colour | Light grey. |
| Clutch fluid | Lockheed Super Heavy Duty. |
| GENERAL DATA-continued |
948 cc Engine
Gearbox
| Number of forward speeds | .. 4. |
| Synchromesh | Second, third, and top gears. |
| Ratios: Top | .. 1·0 : 1. |
| Third | .. 1·357: I. |
| Second | 1·916: I. |
| First | 3·200 : 1. |
| Reverse | .. 4·114:1. |
| Overall ratios: Top | 4·22 : 1. |
| Third | 5·726 : 1. |
| Second | 8·085 : I. |
| First | 13·504 : 1. |
| Reverse | .. 17·361 : 1. |
| Speedometer gear ratio | 5/13. |
Steering
| Type | Rack and pinion. |
| Steering-wheel turns-lock to lock | 2¼. |
| Steering-wheel diameter | 16 in. (40·6 cm.). |
| Camber angle | ¾o. |
| Castor angle | 30. Static |
| King pin inclination | 6¾o. unladen |
| Toe-in | 0 to i in. condition. |
| Steering lock angle of outer wheel with inner wheel at 20° | 18½0 • |
Front Suspension
| Type | .. Independent. Coil springs. |
| Free length | 9·4 in. (23·8 cm.). |
| Mean coil diameter | 3·625 in. (9·2 cm.). |
| Number of effective coils | 7. |
| Working load | 750 lb. (340 kg.). |
| Spring rate | 271 lb. in. (3-127 kg. m.). |
| Dampers (front) | Lever arm type. |
Rear Suspension
| Type | Quarter-elliptic. |
| Spring details: Number of leaves | 15. |
| Thickness of leaves | 5 at -A-in. (3·97 mm.), 10 at tin. (3·18 mm.). |
| Width of leaves | 1¾in. (44·45 mm.). |
| Working load | 375 lb. (170 kg.). |
| Free camber | 3i2-in. (81-76 mm.). |
| Dampers (rear) | . . Lever arm type. |
Propeller Shaft
| Type | Tubular. Reverse spline. |
| Make and type of joints | Hardy Spicer. Needle-roller. |
| Propeller shaft length (between centres of joints) | 26¼ in. (66·6 cm.). |
| Diameter | 1¾in. (44·45 mm.). |
Rear Axle
| Type | Three-quarter-floating. |
| Ratio | 9/38 (4·22 : 1). |
| (Later cars) | 3·9: 1 |
| GENERAL DATA-continued |
948 cc Engine
Electrical Equipment
| System | 12-volt. Positive earth. |
| Charging system | Compensated voltage control. |
| Battery | Lucas BT7A (BTZ7A Export). |
| Capacity | 43 amp.-hr. (at 20-hour rate). |
| Electrolyte to fill one cell | ¾pint (430 c.c., t U.S. pint). |
| Starter motor | Lucas 4-brush M35G/l. |
| Dynamo | Lucas C39. |
| Maximum output | 19 amps. |
| Field coil resistance | 6·1 ohms±5%. |
| Control box | Lucas RB 106. |
| Cut-out: Cut-in voltage | 12·7 to 13·3. |
| Drop-off voltage | . . 8·5 to 11·0. |
| Reverse current | 5·0 amps. (max.). |
| Open-circuit setting at 20° C. (68° F.) | . . 16·0 to 16·6 volts. |
Brakes
| Type | Lockheed hydraulic. |
| Front | Two leading shoes. |
| Rear | Single leading shoe. |
| Drum size | 7 in. (17·78 cm.). |
| Lining dimensions: Front and rear | 6¾ in. x 1¼in. (17-14 cm. x 3-175 cm.). |
| Total lining area | 67·5 sq. in. (435·37 cm.2). |
| Brake fluid | Lockheed Super Heavy Duty. |
Wheels
| Type | Ventilated disc. 4-stud fixing. |
Tyres
| Size | 5·20-13. |
| Tyre pressures-normal and fully loaded: Front | 18 lb./sq. in. (l ·27 kg./cm. 2). |
| Rear | 20 lb./sq. in. (I ·41 kg./cm. 2). |
| (129-136 km.p.h.) increase pressure to: Front | 24 lb./sq. in. (1 ·69 kg./cm. 2). |
| Rear | 26 lb./sq. in. (1 ·83 kg./cm.2). |
| CAPACITIES | Imp. U.S Litres |
| Engine sump (including filter) | 6·5 pts. 7·8 pts. 3·7 |
| Gearbox | 2·25 pts. 2·7 pts. 1·3 |
| Rear axle | 1·75 pts. 2· l pts. ·99 |
| Cooling system (without heater) | 10 pts. 12 pts. 5·68 |
| Heater | ·5 pt. ·6 pt. ·25 |
| Fuel tank | 6 gal. 7·2 gal. 27·3 |
General Dimensions
| Wheelbase | 6 ft. 8 in. (2·03 m.). |
| Overall length | 1I ft. 5¾ in. (3·49 m.). |
| Overall width | 4 ft. 5 in. (1 ·35 m.). |
| Overall height | 4 ft. 1¾in. (1·25 m.). |
| Ground clearance | 5 in. (12·7 cm.). |
| Turning circle: Left lock | 32 ft. 1½in. (9·79 m.). |
| Right lock | 31 ft. 2½ in. (9·51 m.). |
| Track: Front | 3 ft. 9¾ in. (1·16 m.) (static unladen condition). |
| Rear | 3 ft. 8¾ in. (1 •14 m.). |
| Vehicle weight (dry) | .. 1,400 lb. (635 kg.). |
| GENERAL DATA-continued |
948 cc Engine
Weights Of Components
| Engine | 246 lb. (111·5 kg.). |
| Gearbox | .. 44 lb. (19·95 kg.). |
| Axle | .. 83 lb. (37·64 kg.). |
Torque Wrench Settings
| Cylinder head nuts | . . 40 lb. ft. (5·5 kg. m.). |
| Main bearing set screws | . . 60 lb. ft. (8·3 kg. m.). |
| Connecting rod bolts | . . 35 lb. ft. (4·8 kg. m.). |
| Flywheel securing bolts | 40 lb. ft. (5·5 kg. m.). |
| Steering-wheel nut | 40 lb. ft. (5·5 kg. m.). |
| Road wheel nuts | . . 45 lb. ft. (6·22 kg. m.). |
| Rear damper bolts | . . 25 lb. ft. (3·4 kg. m.). |
| Front hub nuts | 25 to 65 lb. ft. (3·4 to 8·9 kg. m.). |
| GENERAL DATA |
1098 cc Engine
Use in conjunction with 948 cc specifications above. Only differences are listed.
1098 cc Engine
Use in conjunction with 948 cc specifications above. Only differences are listed.
Engine
| Type | .. IOCG. |
| Bore | 2·543 in. (64·58 mm.). |
| Stroke | . . 3·296 in. (83·72 mm.). |
| Capacity | 67 cu. in. (1098 c.c.). |
| Compression ratio | 8·9: 1 (or8·1: 1). |
| Valve operation | Overhead by push-rod. |
| Oversize bore: 1st | +·010 in. (·254 mm.). |
| Max | +020 in. (·508 mm.). |
| Torque | H.C. 62 lb. ft. (8·6 kg. m.) 3,250 r.p.m. |
| Length | I¼ in. (27 mm.). |
| Type | Solid skirt. |
| Clearances: Bottom of skirt | ·0005 to ·0011 in. (·013 to ·028 mm.). |
| Top of skirt | ·0021 to ·0037 in. (·053 to ·094 mm.). |
| Oversizes | +·010 in., +·020 in. ( +·254 mm., +·508 mm.). |
| Compression: Type: Top ring | Plain, internally chamfered (chrome-faced). |
| Second and third rings | Tapered. |
| Width: Top ring | ·062 to ·0625 in. (1·575 to l ·587 mm.). |
| Second and third rings | ·0615 to ·0625 in. (1·558 to 1·587 mm.). |
| Clearance in groove | ·002 to ·004 in. (·051 to ·102 mm.). |
| Oil control: Type: Early engines | Slotted scraper. |
| Thickness | ·106 to •112 in. (2·69 to 2·84 mm.). |
| Type: Later engines | Wellworthy-Duraflex 61. |
| Fitted gap: Rails | ·012 to ·028 in. (·31 to ·7 mm.). |
| Side spring | ·10 to ·15 in. (2·54 to 3·81 mm.). |
| Type | Fully floating. |
| Fit in piston | Hand push fit. |
| Head diameter: Inlet | 1·213 to 1·218 in. (30·81 to 30·94 mm.). |
Fuel System
| Needles: Standard | GY. |
| Weak | GG. |
| Piston spring | .. Blue. |
Cooling System
| Standard | 82° C. (180° F.). |
| Hot climates | 74° C. (165° F.). |
| Cold climates | 88° C. (190° F.). |
| GENERAL DATA |
Engine
| Type | 10cc. |
| Torque | .. H.C. 65 lb. ft. (8·9 kg. m.) at 3,500 r.p.m. |
| Main journal diameter | .. 2·0005 to 2·0010 in. (50·79 to 50·80 mm.). |
Fuel System
| Needles | .. Standard AN. Rich H6. Weak GG. |
| Make and type | .. S.U. (electrical) Type AUF200. |
| Delivery rate | 56 pints/hr. (67 U.S. pints/hr., 32 litres/hr.). |
| Delivery pressure | .. 2·5 to 3·0 lb./sq. in. (·17 to ·21 kg./cm. 2). |
Front Suspension
| Spring free length | .. 9·59 in. (24·4 cm.). |
Rear Suspension
| Type | .. Semi-elliptic. |
| Spring details: Number of leaves | .. 5. |
| Width of leaves | 1½in. (38·10 mm.). |
| Working load | .. 375 lb. (170 kg.). |
| Free camber | 4·437 (112·7 mm.). |
Tyres
| (129-136 km.p.h.) increase pressure to: Front | . . 22 lb./sq. in. (1-55 kg./cm. 2). |
| Rear | . . 24 lb./sq. in. (1·69 kg./cm. 2). |
Weights
| Vehicle weight (dry) | .. 1,490 lb. (676 kg.). |
Torque Wrench Seitings
| Cylinder side cover (deep pressed type) | .. 5 lb. ft. (·7 kg. m.). |
| GENERAL DATA |
Sprite Mk IV / Midget Mk III (1275 cc)
Use in conjunction with preceding specifications. Only differences are listed.
Engine
| Type: Early cars | 12cc, 12cE. |
| Midget Mk. III from Car No. G-AN5-105501 | 12V. |
| Number of cylinders | 4. |
| Bore | 2·78 in. (70·61 mm.). |
| Stroke | 3·2 in. (81·28 mm.). |
| Capacity | 77·8 cu. in. (1274·86 c.c.). |
| Firing order | 1, 3, 4, 2. |
| Valve operation | Overhead by push-rod. |
| Compression ratio: H.C | 8·8: 1. |
| L.C | 8·0: 1. |
| B.M.E.P.: H.C. (Standard) | 139 lb./sq. in. (9·77 kg./cm. 2) at 3,000 r.p.m. |
| L.C. (Standard) | 127 lb./sq. in. (8·93 kg./cm. 2) at 3,000 r.p.m. |
| Torque: H.C. (Standard) | 72 lb. ft. (9·96 kg. m.) at 3,000 r.p.m. |
| L.C. (Standard) | 64·5 lb. ft. (8·91 kg. m.) at 3,000 r.p.m. |
| Cranking pressure: H.C | 120 lb./sq. in. (8·44 kg.fem.a-,at 350 r.p.m. |
| Engine idle speed | 650 to 700 r.p.m. |
| Oversize bore: 1st | ·010 in. (·254 mm.). |
| Max | ·020 in. (·508 mm.). |
| Main journal diameter | 2·0005 to 2·0010 in. (50·813 to 50·825 mm.). |
| Crankpin journal diameter | 1·6252to 1·6259 in. (41·28 to 41·29 mm.). |
| Regrind-Main and crankpin journals | Maximum permissible, without heat treatment: |
| Crankshaft end-thrust | Taken by thrust washers at centre main bearing. |
| Crankshaft end-float | ·002 to ·003 in. (·051 to ·076 mm.). |
| Number and type | 3 thin-wall; split shells, steel backed: copper-lead- |
| Material | VP3 lead-indium or NFM/3B. |
| Length | ·975 to ·985 in. (24·765 to 25·019 mm.). |
| Diametrical clearance | ·0010 to ·0027 in. (·0254 to ·067 mm.). |
| Type | Horizontally split big-end, plain small-end. |
| Length between centres | 5·748 to 5·792 in. (145·99 to 145·101 mm.). |
| Type and material | Steel-backed lead-indium· plated. |
| Length | ·840 to ·850 in. (21-336 to 21·590 mm.). |
| Diametrical clearance | ·0010 to ·0025 in. (·0254 to ·063 mm.). |
| End-float on crankpin | ·006 to ·010 in. (·15 to .·254 mm.). |
| Type | Aluminium solid skirt dished crown. |
| Clearance in cylinder: Top of skirt | ·0029 to ·0037 in. (·074 to ·095 mm.). |
| Bottom of skirt | ·0015 to ·0021 in. (·038 to ·054 mm.). |
| Number of rings | 4 (3 compression, 1 oil control). |
| Width of ring grooves: Top, second, and third | ·0484 to ·0494 in. (1·229 to 1·255 mm.). |
| Oil control | ·1578 to ·1588 in. (4·008 to 4·033 mm.). |
| Gudgeon pin bore | ·8125 to ·8129 in. (20·638 to 29·647 mm.). |
| GENERAL DATA-continued | |
| Type: Top | .. Internally chamfered chrome. |
| Second and third | .. Tapered cast iron. |
| Fitted gap: Top | .. ·011 to ·016 in. (·279 to ·406 mm.). |
| Second and third | .. ·008 to ·013 in. (·203 to ·330 mm.). |
| Type | .. Duaflex 61. |
| Type | Pressed in connecting rod. |
| Fit in piston | Hand push-fit. |
| Diameter (outer) | ·8123 to ·8125 in. (20·63 to 20·64 mm.). |
| Fit to connecting rod | ·0008 to ·0015 in. (·020 to ·038 mm.) interference. |
| Journal diameters: Front | 1·6655 to 1·6660 in. (42·304 to 42·316 mm.). |
| Rear | 1·37275 to l ·37350 in. (34·866 to 34·889 mm.). |
| Bearing liner inside diameter (reamed after fitting): Front | 1·6670 to 1·6675 in. (42·342 to 42·355 mm.). |
| Centre | 1·62425 to 1·62475 in. (41·256 to 41·369 mm.). |
| Rear | 1·3745 to 1·3750 in. (34·912 to 34·925 mm.). |
| Bearings: Type | White-metal lined, steel backed. |
| Diametrical clearance | ·001 to ·002 in. (·0254 to ·0508 mm.). |
| End-thrust | Taken on locating plate. |
| End-float | ·003 to ·007 in. (·076 to ·178 mm.). |
| Cam lift | ·250 in. (6·35 mm.). |
| Drive | Duplex chain and gear from crankshaft. |
| Timing chain | ¾in. (9·52 mm.) pitch x 52 pitches. |
| Type | Bucket. |
| Outside diameter | ·81175 to ·812 in. (20·618 to 20·64 mm.). |
| Diameter | .. ·5615 to •5625 in. (14·262 to 14·287 mm.). |
| Bore | ·686 to ·687 in. (17·424 to 17·449 mm.). |
| Rocker arm bush inside diameter | ·5630 to ·5635 in. (14·3 to 14·313 mm.). |
| Seat angle: Inlet and exhaust | 45°. |
| Head diameter: Inlet | 1·307 to 1·312 in. (33-198 to 33·21 mm.). |
| Exhaust | 1·1515 to 1-1565 in. (29·243 to 29·373 mm.). |
| Stem diameter: Inlet | ·2793 to ·2798 in. (7·094 to 7·107 mm.). |
| Exhaust | ·2788 to ·2793 in. (7·081 to 7·094 mm.). |
| Stem to guide clearance: Inlet and exhaust | ·0015 to ·0025 in. (·0381 to ·0778 mm.). |
| Valve lift: Inlet and exhaust | .. ·318 in. (8·076 mm.). |
| GENERAL DATA-continued | |
| Valve springs | Outer Inner |
| Free length l ·828 in. (46·47 mm.) | 1-703 in. (43·26 mm.). |
| Fitted length | 1·383 in. (35-13 mm.). 1·270 in. (32·26 mm.). |
| Load at fitted length | 51 lb. (23·1 kg.). 25 lb. (11·3 kg.). |
| Load at top of lift | 87 lb. (39·5 kg.). 44 lb. (20 kg.). |
| Valve crash speed | 6,750 r.p.m. |
| Timing marks | Dimples on timing gears. |
| Rocker clearance: Running (Standard) | ·012 in. (·30 mm.) cold. |
| (Competition work) | ·015 in. (·38 mm.) cold. |
| Timing | ·029 in. (·72 mm.). |
| Inlet valve: Opens | 5° B.T.D.C. |
| Closes | 45° A.B.D.C. |
| Exhaust valve: Opens | 51° B.B.D.C. |
| Closes | 21° A.T.D.C. |
| System pressure: Running | 40 to 70 lb./sq. in. (2·81 to 4·92 kg.fcm. 2). |
| Idling | 20 lb./sq. in. (l ·4 kg.fem.I). |
| Oil pump | Eccentric rotor: splined drive from camshaft. |
| Oil filter | Full-flow type; renewable element: differential pres- |
| Oil pressure relief valve | 50 lb./sq. in. (5·3 kg.fem.I). |
| Relief valve spring: Free length | 2·86 in. (72·64 mm.). |
| Fitted length | 2·156 in. (54·77 mm.). |
| Load at fitted length | 13 to 14 lb. (5·90 to 6·35 kg.). |
Ignition System
| Coil | Lucas 11C 12. |
| Resistance at 20° C. (68° F.) primary winding | 3 to 3·4 ohms. |
| Consumption: Ignition switch on | 3·5 to 4 amps. |
| At 2,000 r.p.m | 1 amp. |
| Distributor | Lucas 23D4. |
| Rotation of rotor arm | Anti-clockwise. |
| Cam closed period | 60°±3°. |
| Cam open period | 30°±3°. |
| Serial number | 40819. 41198. |
| Type | 23D4. 25D4. |
| Automatic advance | Centrifugal. Centrifugal and vacuum. |
| Crankshaft degrees-(vacuum pipe disconnected) | 0°-3° at 600 r.p.m. 0°-1° at 600 r.p.m. |
| 6°-12° at 1,000 r.p.m | 2°-6° at 800 r.p.m. |
| 11°-15° at 2,000 r.p.m | 4°-8° at 1,000 r.p.m. |
| 22°-26° at 5,200 r.p.m | 10°-14° at 2,000 r.p.m. |
| 28°-32° at 7,000 r.p.m | 20°-24° at 5,600 r.p.m. |
| Starts | 5 in. Hg. |
| Finishes | 8 in. Hg. |
| Total crankshaft degrees | 60±20. |
| Contact point gap setting | ·014 to ·016 in. (·35 to ·40 mm.). |
| Breaker spring tension | 18 to 24 oz. (510 to 680 gm.). |
| Condenser capacity | ·18 to ·24 mF. |
| Timing marks | Pointer on timing chain case and notch in crankshaft |
| GENERAL DATA-continued | |
| (SPRITE (Mk | IV) and MIDGET (Mk. lll)-con t inued) |
| Static ignition timing: H.C | 7° B.T.D.C. |
| L.C | 7° B.T.D.C. |
| Stroboscopic ignition timing | 22° at 1,200 r.p.m. (23D4 distributor). |
| Sparking plugs | Champion N9Y. |
| Size | 14 mm. |
| Gap | ·024 to ·026 in. (·62 to ·66 mm.). |
Cooling System
| Thermostat settings: Standard | 82° C. (180° F.). |
| Hot countries | 74° C. (165° F.). |
| Cold countries | 88° C. (190° F.). |
| Pressure cap: Early cars | 7 lb./sq. in. (·49 kg./cm.2). |
| Later cars | 15 lb./sq. in. (l ·O5kg./cm.2). |
| Capacity with heater | 6 pints (3·4 litres, 7 U S. pints). |
Fuel System
| Carburetter | Twin S.U. Type H.S.2. |
| Choke diameter | 1·25 in. (31-75 mm.). |
| Jet size | ·090 in. (2·29 mm.). |
| Needles | Standard AN; Weak GG; Rich H6. |
| Piston spring | Light blue. |
Clutch
| Make and type | Borg & Beck; diaphragm-spring type. |
| Clutch plate diameter | 6·5 in. (165 mm.). |
| Facing material: Early cars | Wound yarn. |
| Later cars | Thermo id 11046 |
| Number of damper springs | 4. |
| Damper spring colour | 2 lavender, 2 white and violet. |
| Clutch release bearing | Carbon pad. |
| Clutch fluid | Lockheed Disc brake (Series II). |
Heering
| Type | Rack and pinion. |
| Early cars | 2·25. |
| Midget Mk. III from Car No. G-AN5-114643 | 2·8. |
| Steering-wheel diameter | 15½in. (39·4 cm.). |
| Toe-in | 0 to¼ in. (0 to 3·17 mm.). |
| Camber angle | ¾o• |
| Caster angle | 30, |
| Midget Mk. III from Car No. G-AN5-ll4643 | ·010 in. (·25 mm.). |
| Early cars | 6¾0±1¼0. |
| Later cars: Laden | 6° 30'} |
| Unladen | 60 45' ±10 15'. |
| Early cars | 19¾ ±1-¼ |
| Later cars | 19° 3o':::W. |
Rrakes
| Lining material: front | Ferodo 2424F-GG. |
| rear | Ferodo AMS-FF. |
| Brake fluid | Lockheed Disc Brake (Series II). |
| Front brake disc size: Standard width | ·300 to ·305 in. (7·62 to 7·75 mm.). |
| Minimum permissible width | ·29 in. (7·37 mm.). |
| GENERAL DATA-continued |
Wheels
| Size and type (Pressed spoked) | 4-½JSLx 13. |
| (Pressed disc) | 3·5D X 13. |
| (Wire) | 4J X 13. |
Gearbox
| Number of forward speeds | 4. |
| Synchromesh | .. Second, third, and top gears. |
| Ratios: Top | 1·0 : 1. |
| Third | 1·357 : 1. |
| Second | 1·916 : 1. |
| First | 3·200 : 1. |
| Reverse | 4·114: 1. |
| Overall ratios: Top | 3·9: 1. |
| Third | 5·292 : 1. |
| Second | 7·472 : 1. |
| First | 12·480 : 1. |
| Reverse | 16·044 : 1. |
| Speedometer gear ratio | 5/13. |
Tyre Pressures
| 5·20-13S | 145SR-13 |
| Cross-ply tyres | Radial-ply tyres |
| Front | Rear Front Rear |
| 18 lb./sq. in | 20 lb./sq. in. 22 lb./sq. in. 24 lb./sq. in. |
| 18 lb./sq. in | 24 lb./sq. in. 22 lb./sq. in. 26 lb./sq. in. |
Weights
| Including | Total weight Distribution |
| Front | Rear |
| Kerbside | Full fuel tank, ali 1,701 lb. 861 lb. 840 lb. |
| Normal | Kerbside weight, 2,001 lb. 959 lb. 1,042 lb. |
| Maximum | Normal weight and 2,151 lb. 926 lb. 1,225 lb. |
| Maximum permissible towing weight | 1,344 lb. |
| Towbar hitch load | Maximum |
| GENERAL DATA-continued |
Capacities
| Fuel tank: Midget Mk. III from Car No. G-AN5-105501 | 7 gallons (32 litres). |
| DIMENSIONS | Pressed spoked wheels Wire wheels Pressed disc wheels |
| Turning circle: Later cars | 32 ft. 5 in. (9·88 m.). |
| Track: Front | 3 ft. 10¼ in. (1-18 m.). 3 ft 10¼ in. (1-18 m.). 3 ft. 10¼ (1-18 m.). |
| Rear | 3 ft. 10 in. (1-17 m.). 3 ft. 9¼in. (1•15 m.). 3 ft. 8¾in. (1-14 m.). |
| Overall width | 4 ft. 8½in. (1·5 m.). 4 ft. 6-i in. (1 ·4 m.). |
| Overall height | 4 ft. i in. (1·22 m.). |
| Overall width | . . 4 ft. 5-i in. (1·36 m.). 4 ft. 8¼in. (1·44 m.) 4 ft. 6-i in. (1 ·39 m.). |
| Cross-ply tyres | . . 4 ft. i in. (1·24 m.). 4 ft. i in. (1·24 m.) 4 ft. i in. (l ·24 m.). |
| Radial-ply tyres | . . 4 ft. ¼in. (1·23 m.). 4 ft. -¼in. (l ·23 m.). 4 ft. ¼in. (1·23 m.). |
| from Car No. G-AN5-138801) | 11 ft. 4½in. (3·47 m.). 11 ft. 4½in. (3·47 m.) 11 ft. 4½in. (3·47 m.). |
Torque Wrench Setiings
| Oil pump securing bolts | 12 lb. ft. (l ·66 kg. m.). |
| Plain studs | 42 lb. ft. (5·81 kg. m.). |
| Studs stamped 22 or with small drill point | 50 lb. ft. (6·91 kg. m.). |
| Connecting rod nuts | 40 lb. ft. (5·53 kg. m.). |
| Fan securing bolts | 100 lb. in. (1-15 kg. m.). |
| Road wheel nuts | 45 lb. ft. (6·22 kg. m.). |
| Steering-column pinch bolt | 9 to 11 lb. ft. (1·2 to 1·5 kg. m.). |
| Oil filter | 10 to 15 lb. ft. (1-38 to 2 kg. m.). |
| Petrol tank drain plug | 100 to 120 lb. in. (1-15 to 1·38 kg. m.). |
| Oil pipe union adaptor-oil filter head | 19 to 21 lb. ft. (2·63 to 2·9 kg. m.). |
| Clutch bolts | . . 18 to 22 lb. ft. (2·49 to 3·04 kg. m.). |
| Steering rack clamp bolts | 20 to 22 lb. ft. (2·77 to 3·04 kg. m.). |
| Steering rack mounting bracket retaining bolts | 23 to 25 lb. ft. (3·18 to 3·46 kg. m.). |
| Tie-rod end assembly locknut | . . 30 to 35 lb. ft. (4·15 to 4·84 kg. m.). |
| Tie-rod end assembly ball joint nut | 28 to 32 lb. ft. (3·87 to 4·48 kg. m.). |
| Tie-rod inner ball joint assembly locknut | . . 80 lb. ft. {ll ·06 kg. m.). |
Electrical
| Make/type | Lucas RB340. |
| Setting at 20° C. (68° F.), 3,000 r.p.m. dynamo | 14·5 to 15·5 volts. |
| Cut-in voltage | 12·7 to 13·3 volts. |
| Drop-off voltage | 9·5 to 11·0 volts. |
| Make/type | Lucas M35J. |
| Brush spring tension | 28 oz. (·8 kg.). |
| Minimum commutator thickness | ·08 in. (2·05 mm.). |
| Lock torque | 7 lb. ft. (·97 kg. m.) at 250-375 amps. |
| Light running current | 65 amps. at 8,000 to 10,000 r.p.m. |
| Maximum armature end-float | ·010 in. (·25 mm.). |
| Torque at 1,000 r.p.m | 4·4 lb. ft. (·61 kg. m.) at 260 to 275 amps. |
| GENERAL DATA-continued | |
| Make/type | Lucas A9/AZ9-All/AZ11. |
| Capacity at 20-hr. rate | A9/AZ9: 40 amp. hr. |
| Make/type | Lucas 7FJ. |
| Type | Lucas 16ACR. |
| Brush length-new | ·5 in. (12·6 mm.). |
| Brush length-minimum | ·2 in. (5 mm.) protruding beyond brush box moulding. |
| Brush spring pressure | 9 to 13 oz. (255 to 369 gm.) when brush is pushed in |
| Rotor with forged claw | .. 4·3 ohms±5%. |
| Rotor with pressed claw | 3·3 ohms±5%. |
| Current flow at 12 volts | 3 amperes. |
| Insulation test equipment | . . I IO-volt A.C. supply and 15-watt test lamp. |
| Continuity test equipment | 12-volt D.C. supply and 36-watt test lamp. |
| Diode current test equipment | 12-volt D.C. supply and l ·5-watt test lamp. |
| Alternator output at 14 volts | 34 amperes at 6,000 alternator r.p.m. |
| Spring coil diameter (mean) | 3·575 to 3·625 in. (9· l to 9·2 cm.). |
| Free height | 9·85 in. (25 cm.). |
| Fitted length at load of750± 15 lb. (337±6·8 kg.) | 7·08 in. (18 cm.). |
| Number of effective coils | 7. |
| GENERAL DATA-continued |
Engine
| Type (1969-70) | 12CD (EEC). |
| Type (1970-71) | 12CJ (EEC, ELC). |
| Type (1971-72) | 12V 5872 (EEC, ELC). |
| Type (1972-74) | 12V 6712 (EEC, ELC). |
| Abbreviations: EEC, Exhaust Emission Controls | ELC, Evaporative Loss Control. |
| Valve guides | ·5 molybdenum added. |
Fuel System
| Early cars | 6 U.S. gallons (22·7 litres). |
| Midget Mk. III from Car No. G-AN5-I05501 | 7 U.S. gallons (27·3 litres). |
| Type | S.U. electric AUF 300. |
| Minimum flow | 18 U.S. gal./hr. (68·2 litresihr.). |
| Suction head | 18 in. (·457 mm.). |
| Delivery head | 4 ft. (122 cm.). |
| Type | S.U. electric AUF 305. |
| Delivery pressure | 2·8 to 3·8 lb./sq. in. (0·2 to 0·27 kg./m.2). |
Brakes
| Lining material: front | Ferodo 2424F-GG. |
| rear | Ferodo AMS-FF. |
| Brake fluid | Lockheed Disc Brake (Series 329). |
Electrical
| Type | Lucas 16ACR. |
| Brush length-new | 0·5 in. (12·6 mm.). |
| Brush length-minimum | 0·2 in. (5 mm.) protruding beyond brush box mould- |
| Brush sp.-ingpressure | 9 to 13 oz. (255 to 369 gm.) when brush is pushed in |
| Resistance | 4·33 ohms. |
| Current flow at 12 volts | 3 amperes. |
| Insulation test equipment | I IO-volt A.C. supply and IS-watt test lamp. |
| Continuity test equipment | 12-volt D.C. supply and 36-watt test lamp. |
| Insulation test equipment | 110-volt A.C. supply and 15-watt test lamp. |
| Diode current test equipment | 12-volt D.C. supply and l ·5-watt test lamp. |
| Alternator output at 14 volts | 34 amperes at 6,000 alternator r.p.m. |