Specifications from the official MGA Workshop Manual, covering both the MGA (1500) and MGA 1600 models.
Engine
MGA (1500)
| Type | 15GB (from Car No. 61504: 15GD) |
| Number of cylinders | 4 |
| Bore | 2.875 in. (73.025 mm.) |
| Stroke | 3.5 in. (89 mm.) |
| Capacity | 90.88 cu. in. (1,489 cc.) |
| Firing order | 1, 3, 4, 2 |
| Compression ratio | 8.3 : 1 |
| Valve operation | Overhead by push-rod |
| B.M.E.P. | 130 lb./sq. in. at 3,500 r.p.m. |
| Torque | 77.4 lb. ft. at 3,500 r.p.m. |
| Cooling system | Thermo-siphon, pump- and fan-assisted |
| Oversize bore (1st) | .010 in. (.254 mm.) |
| Oversize bore (max) | .040 in. (1.016 mm.) |
MGA 1600
| Type | 16GA |
| Number of cylinders | 4 |
| Bore | 2.968 in. (75.39 mm.) |
| Stroke | 3.5 in. (89 mm.) |
| Capacity | 96.9 cu. in. (1,588 cc.) |
| Firing order | 1, 3, 4, 2 |
| Compression ratio | 8.3 : 1 |
| Valve operation | Overhead by push-rod |
| Maximum b.h.p. | 79.5 at 5,600 r.p.m. |
| Torque | 87 lb. ft. at 3,800 r.p.m. |
| Cooling system | Thermo-siphon, pump- and fan-assisted |
| Oversize bore (1st) | .010 in. (.254 mm.) |
| Oversize bore (max) | .040 in. (1.016 mm.) |
Crankshaft
| Main journal diameter | 2 in. (50.8 mm.) |
| Minimum regrind diameter | 1.96 in. (49.78 mm.) |
| Crankpin journal diameter | 1.8759 to 1.8764 in. (47.65 to 47.66 mm.) |
| Crankpin minimum regrind | 1.8359 in. (46.64 mm.) |
| Main bearings | 3, Shell-type, Steel-backed white metal |
| Main bearing length | 1.375 in. (34.925 mm.) |
| End-clearance | .002 to .003 in. (.051 to .076 mm.) |
| End-thrust | Taken by thrust washers at centre main bearing |
| Running clearance | .0005 to .002 in. (.0127 to .0508 mm.) |
Connecting Rods
| Length between centres | 6.5 in. (165.1 mm.) |
| Big-end bearing material (MGA 1500) | Steel-backed lead-indium or lead-tin |
| Big-end bearing material (MGA 1600) | Steel and lead-indium |
| Side clearance | .008 to .012 in. (.203 to .305 mm.) |
| Diametrical clearance (MGA 1500) | .0001 to .0016 in. |
| Diametrical clearance (MGA 1600) | .0010 to .0025 in. |
Pistons
| Type | Aluminium alloy |
| Clearance, bottom of skirt | .0017 to .0023 in. |
| Clearance, top of skirt | .0035 to .0042 in. |
Piston Rings (MGA 1500)
| Compression plain | Top ring |
| Tapered | 2nd and 3rd rings |
| Width | .0615 to .0625 in. |
| Fitted gap | .008 to .013 in. |
| Oil control | Slotted scraper |
Gudgeon Pin
| Type | Clamped |
| Fit | Hand push at 68°F (20°C) |
| Diameter | .6869 to .6871 in. |
Valves and Timing
| Seat angle | 45° |
| Head diameter, inlet | 1.5 in. (38.1 mm.) |
| Head diameter, exhaust | 1.281 in. (32.54 mm.) |
| Stem diameter | .342 in. (8.68 mm.) |
| Valve lift (MGA 1500) | .357 in. (9.06 mm.) |
| Valve lift (MGA 1600) | .350 in. (8.89 mm.) |
| Rocker clearance, running (MGA 1500) | .017 in. (.432 mm.) hot |
| Rocker clearance, running (MGA 1600) | .015 in. (.38 mm.) cold |
| Valve guides | Removable |
| Timing markings | Dimples on timing wheels |
| Chain pitch | 3/8 in. (9.52 mm.), 52 pitches |
| Inlet opens | 16° B.T.D.C. |
| Inlet closes | 56° A.B.D.C. |
| Exhaust opens | 51° B.B.D.C. |
| Exhaust closes | 21° A.T.D.C. |
Camshaft
| Journal diameter, front | 1.789 in. |
| Journal diameter, centre | 1.729 in. |
| Journal diameter, rear | 1.623 in. |
| End-float | .003 to .007 in. |
| Bearings | 3, Thinwall steel-backed white metal |
| Clearance | .001 to .002 in. |
Engine Lubrication
MGA (1500)
| Oil pump type | Eccentric rotor |
| Relief pressure | 75 to 80 lb./sq. in. |
| Oil filter | Tecalemit or Purolator |
| Normal running pressure (min) | 10 to 25 lb./sq. in. |
| Normal running pressure (max) | 50 to 75 lb./sq. in. |
MGA 1600
| Oil pump type | Eccentric rotor |
| Relief pressure | 50 lb./sq. in. |
| Normal running pressure (min) | 15 lb./sq. in. |
| Normal running pressure (max) | 50 lb./sq. in. |
Torque Wrench Settings
| Cylinder head nuts | 50 lb. ft. (6.91 kg. m.) |
| Main bearing nuts | 70 lb. ft. (9.7 kg. m.) |
| Connecting rod set screws | 35 lb. ft. (4.83 kg. m.) |
| Clutch assembly to flywheel | 25 lb. ft. (3.46 kg. m.) |
| Road wheel nuts | 60 to 62.5 lb. ft. |
| Gudgeon pin clamp | 25 lb. ft. |
| Manifold stud nuts | 25 lb. ft. |
| Water pump bolts | 25 lb. ft. |
| Clutch to flywheel bolts | 35 to 40 lb. ft. |
| Oil filter centre-bolt | 15 lb. ft. |
| Brake calliper bolts | 45 to 50 lb. ft. |
Fuel System
| Carburetter | S.U. twin H4 semi-downdraught, 1.5 in. diameter |
| Needle (MGA 1500) | GS |
| Needle (MGA 1600) | No. 6 |
| Jet | .090 in. |
| Piston spring | Red |
| Air cleaner | Vokes oil-wetted |
| Fuel pump | S.U. electric high pressure |
Cooling System
| Type | Pressurized radiator, thermo-siphon, pump- and fan-assisted |
| Thermostat | 70 to 75°C (158 to 167°F) |
Ignition
| Sparking plugs | Champion N5 |
| Plug size | 14 mm. |
| Plug gap | .024 to .026 in. |
| Coil | Lucas HA12 |
| Distributor | Lucas DM2, later DM2.P4 |
| Contact points gap | .014 to .016 in. |
| Timing | 7° B.T.D.C. |
Clutch
| Make and type | Borg & Beck A6-G, Single dry plate |
| Diameter | 8 in. (20.3 cm.) |
| Facing | Wound yarn-Borglite |
| Pressure springs | 6 |
| Release lever ratio | 9 : 1 |
Gearbox
| Synchromesh | Second, third, and fourth |
| Top | 1.0 : 1 (overall 4.3 : 1) |
| Third | 1.374 : 1 (overall 5.908 : 1) |
| Second | 2.214 : 1 (overall 9.520 : 1) |
| First | 3.64 : 1 (overall 15.652 : 1) |
| Reverse | 4.76 : 1 (overall 20.468 : 1) |
Steering
| Type | Rack and pinion |
| Turns lock to lock | 2.75 |
| Steering wheel diameter | 16.5 in. |
| Camber angle | 1° positive to 0.5° negative on full bump |
| Castor angle | 4° |
| King pin inclination | 9° to 10.5° on full bump |
| Toe-in | Wheels parallel |
Track (MGA 1500)
| Front, disc wheels | 47.5 in. |
| Front, wire wheels | 47.875 in. |
| Rear, disc wheels | 48.75 in. |
| Rear, wire wheels | 48.75 in. |
Front Suspension
| Type | Independent coil |
| Dampers | Piston type |
Rear Suspension
| Type | Semi-elliptic |
| Number of leaves | 6 |
| Width | 1.75 in. |
| Working load | 450 lb. |
| Dampers | Piston type |
Rear Axle
| Make and type | B.M.C. ‘B’ type, three-quarter-floating |
| Ratio, standard | 10/43 |
| Ratio, optional | 9/41 |
| Adjustment | Shims |
Brakes
MGA (1500)
| Type | Lockheed hydraulic front and rear |
| Size | 10 in. x 1.75 in. |
| Front | 2 leading shoes |
| Rear | Single leading shoe |
| Lining material | Ferodo DM12 |
MGA 1600
| Type | Lockheed hydraulic, disc front, drum rear |
| Disc diameter | 11 in. |
| Rear lining material | DON24 |
| Option | Also available with Dunlop disc brakes front and rear |
Electrical System
| System | 12-volt, Positive earth |
| Battery | Lucas SG9E, 6-volt (2 off), 58 amp-hr |
| Starter motor | Lucas 4-brush M35G |
| Dynamo (MGA 1500) | Lucas C39PV2 |
| Dynamo (MGA 1600) | Lucas C39PV2 (later C40/1) |
Wheels and Tyres
Wheels
| Disc wheels | 4J x 15 |
| Wire wheels (optional) | 4J x 15, 48-spoke |
Tyres
| Size | 5.60-15 |
| Normal, front | 17 lb./sq. in. |
| Normal, rear | 20 lb./sq. in. |
| Fast motoring, front | 21 lb./sq. in. |
| Fast motoring, rear | 24 lb./sq. in. |
Capacities
| Engine sump (including filter) | 7.5 imp. pts. (9 U.S. pts., 4.25 litres) |
| Gearbox | 4.5 imp. pts. (5.4 U.S. pts., 2.56 litres) |
| Rear axle | 2.25 imp. pts. (2.7 U.S. pts., 1.28 litres) |
| Cooling system | 10 imp. pts. (12 U.S. pts., 5.67 litres) |
| Steering rack | 0.5 imp. pt. (.6 U.S. pt., .28 litre) |
| Fuel tank | 10 imp. gal. (12 U.S. gal., 45.4 litres) |
| Brake system | 1 imp. pt. (1.2 U.S. pts., .568 litre) |
General Dimensions (MGA 1500)
| Wheelbase | 94 in. (238.8 cm.) |
| Overall length | 156 in. (396.2 cm.) |
| Overall width | 58 in. (147.3 cm.) |
| Overall height | 50 in. (127.0 cm.) |
| Ground clearance | 6 in. (15.24 cm.) |
| Weight | 1,988 lb. (901.81 kg.) fully equipped |
| Turning circle | 28 ft. (8.534 m.) |