MGB Specifications

MG Series MGB

Production Period

1962/81

Chassis

Unit Construction body, welded steel constuction, front suspension on subframe.

Wheelbase: 7ft 7in
Track Front: 4ft 1.00in
Rear: 4 ft 1.25in

Steering

Cam Gears rack & pinion system.

Turning circle: 32ft
Castor angle: 7 degrees
Camber angle: 1 degree
Kingpin angle: 8 degrees
Toe in: 0.1875in
Grade of oil: SAE 90

Brakes

Disc front, drum rear.

Disk size front: 10.75in
Drum size rear: 10in
Method of operation: Hydraulic, vacuum servo assisted as option to 1973, standard thereafter. Dual system some markets from '67. Cable operated parking brake.

Wheels

Either steel disc bolt-on, or Rudge type wire spoked. Late cars had alloy wheels as option.

For MkI, MkII-on, Wires
Rim size: 4J * 14, 5J * 14, 4.5J * 14
Tyre Size: 5,60 * 14, 165 * 14
Tyre pressure: 21psi front, 24 psi rear

Engine

4 cylinder in line, pushrod ohv

Bore: 80.26mm
Stroke: 88.90mm
Cubic capacity: 1789cc
Power output: Approx 94bho @ 5500rpm. Later cars had power outputs which varied from market to market. The other tuning details of the unit would be confusing in a table of this type. Please refer to the appropriate Workshop Manual.
Oil pressure: Approx. 60psi. Idle at 20psi
Grade of oil: SAE 20/50
Sump Capacity: 7.5 pints

Ignition Timing

Varies with Engine spec., see above.

Distributor points gap: 0.015in
Sparking plugs: N9YC
Gap: 0.025in. After 1975: 0.035in

Carburetter Type

To 1973: Twin SU HS4
>From 1973: Twin SU HIF4
USA Market also had single Zenith 175CD/5T from 1974/76

Jet size, main: SU 0.090in, Zenith: 0.100
Needle recommendation: Various according to carburettor spec

Clutch

Borg & Beck Single dry plate

Material: Ferodo
Number of springs: Single Diaphragm

Gearbox

Four speed manual, synchromesh on top three ratios to 1965, all synchro after. Electrical overdrive optional, standard from 1975. Borg Warner 35 automatic gearbox was also available 1967 to 1973.

Engine Prefix: 18G- 18GA 18GB on
Ratios: 3sp sync, 4sp sync, B-W auto
Overdrive (where fitted): 0.802, 0.820
Top: 1.000, 1.000, 1.00-1.33
Third o/d (where fitted): 1.10, 1.133
Third: 1.374, 1.382
Second: 2.214, 2.2167, 1.45-1.93
First: 3.640, 3.333, 2.39-3.18
Reverse: 4.760, 3.095, 2.09-2.78
Grade of oil: SAE 30, SAE 20/50 TQF
Capacity: 4.5 pints, 4.7 pints, 6 pints. Add approx. 3pints when o/d fitted

Propellor Shaft

Open shaft, needle roller u/j at each end.

Final Drive

Live axle, hypoid bevel gears.

Ratio: Manual 3.909:1, Auto 3.7:1
MPH/1000rpm: Manual top: 17.9, o/d: 22.1, Auto: 18.91
Grade of oil: SAE 90EP
Capacity: 1.5 pints

Cooling System

Pressurised, thermostatic control, pump assisted. Capacity: 12 pints.

Fuel Tank Capacity

Approx. 12 gallons. Tank located at rear of car under boot floor.

Body Styles

Tourer, GT
Numbers built: MkI

1962 4518
1963 23308
1964 26542
1965 24179 524
1966 22675 10241

MkII introduced

1967 15128 11396
1968 17355 8352
1969 18896 12134
1970 23866 12704
1971 22511 12169
1972 26222 13171
1973 19546 10208
1974 19713 9638
1975 19967 4609
1976 25860 3698
1977 24482 4198
1978 21703 5652
1980 10891 3424