Introduced in September of 1962, the MGB was a stylish two-seat convertible that offered good performance at an affordable price. In three years time, a hatchback coupe would join the little roadster. A six-cylinder roadster and V8 coupe would also be offered.
MGA vs MGB
Larger and more comfortable than the MGA it replaced, the MGB was built around a unitary body, where the floor plan and chassis form a single structure. This design gives a less harsh ride than the body-on-frame design the MGA was built on. It also created more interior room.
Other improvements the MGB had over it's predecessor were front disc brakes, roll-up windows, better weather sealing, and a more luggage capacity. The front suspension and rack and pinion steering were carried over from the MGA.
Basically a bored-out version of the 1622cc MGA engine, the MGB motor was an overhead valve four-cylinder with a displacement of 1798cc. The crankshaft in the original motor rode on three main bearings. This was upgraded to five main bearings in October 1964.
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Induction on 1963 to 1974 MGB's were twin 38mm SU carburetors. All models were factory-fitted with an electric fuel pump.
Originally, MGB's were fitted with a non-synchromesh four-speed manual gearbox. An overdrive unit (operational in third and fourth gears) was optional and was fitted to less than 20% of all cars.
Reclining bucket seats, a leather-wrapped steering wheel, and full carpeting were standard equipment on all models. Dash gauges included a tachometer and trip odometer. Until 1966, a cabin heater was optional.
Positive Ground System
MG sports cars used a 12-volt positive ground system until 1967. Two 6-volt batteries, wired in series, were placed under a panel behind the seats. Although this made battery access difficult, it helped weight distribution, which improved handling. From 1968-on, all MGB's had a negative ground system.
Read: Positive Ground Cars
Originally manufactured by the British Motor Corporation, the MGB was subsequently produced by the Austin-Morris division of British Leyland at their Abingdon, England facility. Through the years 1963 to 1972, approximately 9,000 cars were shipped in "knock-down" form and assembled in Australia.
Introduced in 1965, the hatchback coupe had essentially the same frame, suspension, and drivetrain as the roadster, but the enclosed body offered a quieter, roomier ride with more luggage space. Although not quite as quick due to it's additional weight, the GT coupe had a higher top end speed due to better aerodynamics.
MGC Six Cylinder
The short-lived MGC roadster was produced from 1967-1969. Due to it's length, the six cylinder engine had to be positioned farther forward, prompting a unique bulged hood for radiator clearance, as well as a small bump to clear the carburetors.
The 2912cc engine produced 145 horsepower, but was over 200 pounds heavier than the four cylinder. The extra weight negatively affected handling and steering. As a consequence, only 8,999 examples were built.
U.S. Market Regulations
Now called the MGB Mark II, several upgrades were seen in 1968, including a full synchromesh gearbox. An automatic transmission became available as an extra-cost option.
In order to comply with safety regulations, U.S. bound MG's received a plastic and foam rubber covered "safety" dashboard in 1968. This was the beginning of the "federalized" models.
The 1969 model year saw several more U.S. safety requirements, including side marker lamps and seats with head restraints. A change from two to three windshield wipers was required to sweep the required percentage of the glass (U.S. market only).
A new front grille, recessed in black aluminium, was seen in 1970. A more traditional looking polished grille with a black "honeycomb" insert debuted in 1973.
In North America, split rear bumpers with the license plate in between was seen in 1970. The earlier, single-piece chrome bumper returned in 1971.
MGB GT V8
Boasting a top speed of 124 mph, the V8-equipped MGB GT was offered through the years 1973 to 1976. Standard equipment included alloy wheels, upgraded suspension, tinted windows, and a four-speed gear box with an overdrive unit. The 3528cc aluminum block engine was the lightest production V8 at the time and produced 137 horsepower.
More Safety Regulations
A major restyle in the second half of 1974 saw chrome bumpers replaced with steel-reinforced black rubber bumpers. Further regulations required a minimum headlight height. Rather than redesign the front sheet metal, the car maker raised the car's suspension by 25mm.
Starting in 1975, North American market cars were fitted with a single Zenith Stromberg carburetor. Although it helped reduce emissions like it was designed to do, it also reduced power. Making matters worse, the Stromberg carb was mounted on a combination intake/exhaust manifold, which was prone to cracking.
Read: Zenith Stromberg Carb Rebuild
Since it's introduction in 1962, MGB curb weight had gone up substantially -- over 500 pounds. The combination of heavier bumpers, higher ride height, and emission-laden engines lowered performance and impaired the car's once-great handling.
Although the car was a huge export success for British Leyland, the company faced struggles throughout the 1970s and was never able to rebound. Competition from other sports cars included the Mini Cooper, Triumph TR6, Fiat Spider, and the Datsun 240Z.
End Of Production
The Abingdon factory was shut down in October of 1980. With a production span of 18 years, the MGB is one of the longest running sports car models in automotive history.
Before subjected to federalization, the four-cylinder MGB engine produced 95 horsepower, propelling the 2,000 pound car to 100+ mph. By 1975, the heavier, emission-laden North American models were producing only 85 horsepower. Power output of California-bound cars were even lower. On a positive note, fuel economy was decent for the time, with a 28 mpg average.
For those looking for a sun in your face, wind in your hair, affordable classic sports car, the MGB roadster is a good choice. Although some 70's models were plagued with emissions and awkward safety equipment, all year MG's are capable of better performance with aftermarket upgrades. There is good club and online forum support, and replacement parts are readily available.
Read: Sports Car History
After the 1980 factory closure, the MG marque was resurrected 12 years later with the all-new MG RV8. The semi-retro roadster was offered for sale in limited numbers from 1992-1995.