MGC & MGC GT
|Production||1967–1969 9,002 made (4544 MGC, 4458 MGC GT)|
|Body style||2-door roadster 2-door coupe|
|Engine||2,912 cc (2.9 l) C-Series I6|
The MGC was a 2912 cc, straight-6 version of the MGB sold from 1967 and produced through to August 1969 with some sales running on into 1970. The car was given the model code ADO52. It was intended as a replacement for the Austin-Healey 3000 which would have been ADO51 but in that form, never got beyond the design proposal stage. The first engine to be considered was an Australian-designed six-cylinder version of the BMC B-Series but the production versions used a 7 main bearing development of the Morris Engines designed C-Series that was also to be used for the new Austin 3-litre 4-door saloon. In the twin SU carburettor form used in the MGC the engine produced 145 bhp (108 kW) at 5250 rpm.The body shell needed considerable revision around the engine bay and to the floor pan, but externally the only differences were a distinctive bonnet bulge to accommodate the relocated radiator and a teardrop for carburettor clearance. It had different brakes from the MGB, 15 inch wheels, a lower geared rack and pinion and special torsion bar suspension with telescopic dampers. Like the MGB, it was available as a coupé (GT) and roadster. An overdrive gearbox or three-speed automatic gearbox were available as options. The car was capable of 120 mph (193 km/h) and a 0–60 mph time of 10.0 seconds.
The heavy engine (209 lb heavier than the 1798 cc MGB engine) and new suspension changed the vehicle's handling, and it received a very mixed response in the automotive press. The MGC was cancelled in 1969 after less than two years of production. Today the car is considered very collectible and the main causes of the poor reputation relating to handling have in the main been overcome by better tyres and subtle modification of suspension settings. Simple tuning of the under-developed straight six is also common and simple modifications to head, exhaust and cam release approx 30 percent more power and torque than original.
At the time of the car's launch the manufacturers stated that the Austin-Healey 3000 would continue to be offered as a parallel model, but priced on the domestic market at £1,126 at a time when the MGC came with a recommended sticker price of only £1,102. The statement seems to have been made in order to avoid having to sell off slow moving inventory cars at second hand prices, since Austin-Healey 3000 production ended with the launch of the MG MGC in 1967.
In 1967 HRH Prince Charles took delivery of an MGC GT (SGY 766F), which he passed down to Prince William 30 years later.
Combined production volume of MGB, MGC and MGB GT V8 models was 523,836 cars. A very limited-production "revival" model with only 2,000 units made, called RV8 was produced by Rover in the 1990s. Despite the similarity in appearance to the roadster, the RV8 had less than 5 percent parts interchangeability with the original car.
Engine: All MGBs (except the V8 version) utilized the BMC B-Series engine. This engine was essentially an enlarged version of that used in the MGA with displacement being increased from 1622 cc to 1798 cc. The earlier cars used a three main bearing crankshaft until mid-1965, when a five-bearing crankshaft design was introduced. Horsepower was rated at 95 bhp on both 3 main bearing and earlier 5-bearing cars with peak power coming at 5400 rpm with a 6000 rpm redline. Torque output on all MGB is good with a peak of 110 lb·ft (150 N·m) Fuel consumption was around 25mpg.. 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 2500 rpm. 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 to 1 to 8:1 on US spec cars in 1972.
Carburation: 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 creating longevity problems as the (adjacent) catalytic converter tended to crack the intake–exhaust manifold. All MGBs used a SU-built electronic fuel pump.
Gearbox:: All MGBs from 1962 to 1967 used a four-speed manual gearbox with a non-synchromesh, straight-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 150 hp 3-litre engine of the MGC and was thus over-engineered when mated with the standard MGB B-Series engine. In fact, the same transmission was even used in the 3.5-litre V-8 version of the MGB-GT-V8. An automatic three-speed transmission was also offered as a factory option but proved to be fairly unpopular.
Electrically engaged overdrive gearboxes were an available option on all MGBs. The overdrive unit was operational in third and fourth gears but the overall ratio in third gear overdrive was roughly the same as fourth gear direct. Later cars allowed the overdrive to operate only in fourth gear. The overdrive unit was engaged by a toggle switch located on the dash on 1963–1974 cars and on a gear lever mounted switch on later cars. Overdrives were fitted to less than 20% of all MGBs, making it a very desirable feature.
Rear axle: Early MGBs used the "banjo" type differential carried over from the MGA with the rear axle ratio reduced from the MGA's 4.1 (or 4.3) to 3.9 to 1. (Compensating for the reduction from 15 inch to 14-inch (360 mm) wheels.) MGB GTs first began using a tube-type rear axle in 1967. This unit was substantially stronger being, like the later gearbox, designed for the three-litre MGC. All MGBs used the tube-type axle from 1968.
Brakes: All MGBs were fitted with 11-inch (280 mm) solid (non-ventilated) disc brakes on the front with drum brakes on the rear. The front brake calipers were manufactured by Girling and used two pistons per caliper. The brake system on the MGB GT was the same as the Roadster with the exception of slightly larger rear brake cylinders. A single-circuit hydraulic system was used before 1968 when dual-circuit (separate front and rear systems) were installed on all MGBs to comply with US regulations. Servo assistance (power brakes) was not standard until 1975. Many modern and contemporary testers have commented on the very heavy brake pedal pressure needed to stop the non-servo assisted cars
Electrical system: The MGB initially had an extremely simple electrical system. Dash-mounted toggle switches controlled the lights, ventilation fan, and wipers with only the direction indicators being mounted on a stalk on the steering column. The ignition switch was also mounted on the dash. Like the MGA, the MGB utilized two 6-volt batteries wired in series to give a 12-volt positive earth configuration. The batteries were placed under a scuttle panel behind the seats making access a bit of a challenge but the location gave excellent weight distribution and thus improved handling. The charging system used a Lucas dynamo. Later MGBs had considerable changes to the electrical system including the use of a single twelve-volt battery, a change from positive to negative earth, safety-type toggle switches, an alternator in place of the dynamo, additional warning lights and buzzers, and having most common functions moved to steering column stalks.