Vehicle Specs
1970 MG MGB Conv, nice clean well sorted car, body panels and paint are in very good condition for its age, top is in good order with no tears, nice original interior, chrome bumpers.
Features and inline 4 cylinder engine mated to a 4-speed manual gear box.
Development of the MGB started at least as early as 1958 with the prototype known by its Abingdon codename; MG EX205.[4] 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.[5] 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. From 1975, US-market MGB engines were de-tuned to meet emission standards, ride height was increased by an inch (25 mm), and distinctive rubber bumpers were fitted to meet bumper standards.
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 (200 ton).[6][7] 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.[8]
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.
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.[9] US specification cars saw power fall in 1968 with the introduction of emission standards and the use of air or smog pumps. 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, under ECE15. 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). Some California specification cars produced only around 70 hp (52 kW) by the late 1970s. The compression ratio was also reduced from 9:1 to 8:1 on US spec cars in 1972.
All MGBs from 1963 to 1974 used twin 1.5-inch (38 mm) SU carburettors. US spec cars from 1975 used a single Stromberg 1.75-inch (44 mm) carburettor mounted on a combination intake–exhaust manifold. This greatly reduced power as well as created longevity problems as the (adjacent) catalytic converter tended to crack the intake–exhaust manifold. All MGBs used an SU-built electric fuel pump.
All MGBs from 1962 to 1967 used a four-speed manual gearbox with a non-synchromesh, straight-cut first gear. Optional overdrive[10] 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.[citation needed]
Electrically engaged overdrive gearboxes were an available option on all MGBs. The overdrive unit was operational in third and fourth gears (until 1977, when overdrive was only operational in fourth)[11] but the overall ratio in third gear overdrive was roughly the same as fourth gear direct. The overdrive unit was engaged by a toggle switch on the dashboard or by pulling the wiper lever towards the driver, model dependent. The switch was moved to the top of the gearshift knob in 1977.[11] Overdrives were fitted to less than 20% of all MGBs.
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. By making better use of space the MGB was able to offer more passenger and luggage accommodation than the earlier MGA while being 3 in (76 mm) shorter overall. The suspension was also 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 inches (360 mm).
In late 1967, sufficient changes were introduced for the factory to define a Mark II model for the 1968 model year.[16] Changes included synchromesh on all four gears with revised ratios, an optional Borg-Warner 35 automatic gearbox (except in the US), a new rear axle, and an alternator in place of the dynamo with a change to a negative earth system. To accommodate the new gearboxes there were significant changes to the sheet metal in the floorpan, and a new flat-topped transmission tunnel.
To meet US safety regulations for the 1968 model year, the MGB received a plastic and foam rubber covered "safety" dashboard, dubbed the "Abingdon pillow", and dual circuit brakes. Other markets continued with the steel dashboard. Rubery Owen RoStyle wheels were introduced to replace the previous pressed steel versions in 1969 and reclining seats were standardised.[citation needed]
1969 also saw three windscreen wipers instead of two to sweep the required percentage of the glass (US market only), high seat backs with head restraints and side marker lamps. The next year saw a new front grille, recessed, in black aluminium. The more traditional-looking polished grille returned in 1973 with a black "honeycomb" insert. In North America, 1970 saw split rear bumpers with the number-plate in between, 1971-1974 returned to the earlier single-piece full-length style chrome bumper.[citation needed]
Further changes in 1972 were to the interior with a new fascia.
To meet impact regulations, 1974 US models had the chrome bumper over-riders replaced with oversized rubber ones, nicknamed "Sabrinas" after the British actress Sabrina. In the second half of 1974 the chrome bumpers were replaced altogether. A new, steel-reinforced black rubber bumper at the front incorporated the grille area as well, giving a major restyling to the B's nose, and a matching rear bumper completed the change.
New US headlight height regulations also meant that the headlamps were too low. Rather than redesign the front of the car, British Leyland raised the car's suspension by 1-inch (25 mm). This, in combination with the new, far heavier bumpers, resulted in significantly poorer handling. For the 1975 model year only, the front anti-roll bar was deleted as a cost-saving measure (though still available as an option). The damage done by the British Leyland response to US legislation was partially alleviated by revisions to the suspension geometry in 1977, when a rear anti-roll bar was made standard equipment on all models. US emissions regulations also reduced horsepower.
In March 1979 British Leyland started the production of black painted limited edition MGB roadsters for the US market, meant for a total of 500 examples. Due to a high demand for the limited edition model, production ended with 6,682 examples. The UK received bronze-painted roadsters and a silver GT model limited edition. The production run of homemarket limited edition MGBs was split between 421 roadsters and 579 GTs.
The last MGB roadster produced at Abingdon returned to Abingdon County Hall Museum on 1 December 2011, with the help of British Motor Heritage.[17] It was lifted up 30 feet through a first floor window of the Grade I listed building with inches to spare[18] and now forms part of the collection on display in the main gallery.[19]
Work on a successor for the MGB had been undertaken as early as 1964 with the EX234, but due to the excellent sales of the MGB and Midget, BMC cancelled it in 1966.[20] In 1968 a second proposed replacement was developed, the ADO76, but British Leyland had ceased work on that project by the end of 1970; the ADO76 would ultimately become the rubber-bumper version of the MGB in 1974.[21] When the Abingdon factory finally closed in late 1980, British Leyland did not replace it, with the EX234 prototype finally being sold at auction in 2016.
The decision to discontinue the MGB came about largely due to the poor sales performance of the Triumph TR7, which had largely taken over as BL's contemporary offering in the small sports car market. BL management felt that continued production of the MGB was cannibalising the TR7's sales and this therefore was a justification for taking it off the market. However the TR7 failed to sell and was axed a year later. The MG marque was subsequently used to badge engineer sports versions of the Austin Metro, Austin Maestro and Austin Montego throughout the 1980s, prior to the re-emergence of the MGB in late 1992 as the MG RV8.
