
The MGB replaced the MGA in 1962, and production of the B and its variants continued until 1980. Sales for the MGB, MGC and MGB GT V8 combined totaled 523,836 cars. After a 12-year hiatus, the MGB re-entered production as the heavily modified MG RV8 with a limited run of 2,000 cars before finally being replaced in 1995 by the MG F.
The roadster was the first of the MGB range to be produced. The body was a pure two-seater; a small rear seat was a rare option at one point. The MGB offered better space utilisation to passengers and luggage than the preceding MG A, despite being both 3 in (7.6 cm) shorter in wheelbase and overall length, and 2 in (5.1 cm) lower. Growing in width, gave the MGB a distinctly lower and more squat stance than its forebear. The suspension was softer, giving a smoother ride, and the larger engine gave a slightly higher top speed. The four-speed gearbox was an uprated version of the one used in the MGA with an optional (electrically activated) overdrive transmission. Wheel diameter dropped from 15 to 14 in (36 cm).
Development
of the MGB started at least as early as 1958 with the prototype known by its
Abingdon codename; MG EX205. In structure the car was a progressive, modern
design in 1962, using a unitary structure, instead of the traditional
body-on-frame construction used on both the MGA and MG T-types and the MGB's rival,
the Triumph TR series. However, components such as brakes and suspension were
developments of the earlier 1955 MGA, with the B-Series engine having its
origins in 1947. The lightweight design reduced manufacturing costs while
adding to overall vehicle strength. Wind-up windows were standard, and a
comfortable driver's compartment offered plenty of legroom. A parcel shelf was
fitted behind the seats.

The MGB achieved a 0–60 mph (97 km/h) time of just over 11 seconds. The three-bearing 1,798 cc B-Series engine produced 95 hp (71 kW) at 5,400 rpm – upgraded in October 1964 to a five-bearing crankshaft.
The
MGB was one of the first cars to feature controlled crumple zones designed to
protect the driver and passenger in a 30 mph (48 km/h) impact with an immovable
barrier. Nevertheless, the British AA motoring association has described the
car, like many other classic models, as much less safe than modern cars. The
issue received public attention following a 2013 case in which a driver in a
hired 1963 MGB was killed in a collision with a taxi.

A limited production of 2,000 units of the RV8 was produced by Rover in the 1990s. Despite the similarity in appearance to the roadster, the RV8 had less than 5% parts interchangeability with the original car.
The
MGB remains a popular choice for collectors due to inexpensive and readily
available parts and simple mechanics.
All
MGBs (except the V8 version) used the BMC B-Series engine. This engine was
essentially an enlarged version of that used in the MGA with engine displacement
being increased from 1,622 to 1,798 cc. The earlier cars used a
three-main-bearing crankshaft, 18G-series. In February 1964 positive crank-case
breathing was introduced and the engine prefix changed to 18GA, until October
1964, when a five-bearing crankshaft design was introduced, the engine prefix
became 18GB. Horsepower was rated at 95 net bhp on both five-main-bearing and
earlier three-bearing cars with peak power coming at 5,400 rpm with a 6,000 rpm
redline. Torque output on the MGB had a peak of 110 lb⋅ft (150 N⋅m) and fuel
consumption was around 25 mpg. In 1971 UK spec cars still had 95 bhp (71 kW) at
5,500 rpm, with 105 lb⋅ft
(142 N⋅m)
torque at 2,500 rpm. Engine prefixes became 18V and the SU carburettor needles
were changed for reasons of the latest emission regulations at the time. By
1973 it was 94 bhp (70 kW); by 1974 it was 87, with 103 lb⋅ft (140 N⋅m) torque; by 1975 it
was 85 with 100 lb⋅ft
(140 N⋅m).
All MGBs from 1962 used a four-speed manual gearbox with a non-synchromesh, spur cut first gear. Optional overdrive was available. This gearbox was based on that used in the MGA with some minor upgrades to cope with the additional output of the larger MGB engine. In 1968 the early gearbox was replaced by a full synchromesh unit based on the MGC gearbox. This unit was designed to handle the 150net bhp of the three-litre engine of the MGC and was thus over-engineered when mated with the standard MGB B-Series engine. The same transmission was used in the 3.5-litre V8 version of the MGB-GT-V8. An automatic three-speed transmission was also offered as a factory option, but was unpopular.

The featured car is a 1968 model car privately imported in to Sri Lanka and registered locally in 1978. Currently owned by classic car enthusiast and collector Dinesh Hensman, it is maintained in pristine condition and is used as how a sports car should be used. It has been seen at several classic speed events including the Mahagastotte Classic Hill Climb and is a regular participant at the monthly Sunday Classic Car runs in Colombo. Dinesh also did the Colombo - Jaffna drive organized by a group of car enthusiasts; in the MG B.

MG B Roadster Overview
Production 1962–1980
Body
style 2-door roadster
Engine 1.8
L B-Series I4
Carburation Twin SU
Transmission 4-speed
manual
Wheelbase 2,312
mm (91.0 in)
Length 3,886 mm (153.0 in)
Width 1,524
mm (60.0 in)
Height 1,219
mm (48.0 in)