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Putting a V-8 in an MGB resulted in a real rocket

When the British MG arrived in North America, it immediately became the quintessential sports car, the very definition of the genre.

When the British MG arrived in North America, it immediately became the quintessential sports car, the very definition of the genre. It came first as the neo-classic, square-cut, spider-wheeled MG TC, followed by the evolutionary TD and TF, then the modern envelope-bodied A and B models. But while MG was always the first of a sports car cited, its performance was modest.

The TC and TD could barely break 130 km/h, and the TF wasn't much faster. It took until 1957 for the MGA Coupe to achieve the magical 100 mph (161 km/h). Competitors like Triumph, Austin-Healey and Morgan easily outran it.

The MGA was replaced by the MGB roadster for 1963, followed in 1965 by the MGB GT, a sporty hatchback coupe version with room for a couple of (very) small passengers in the rear. With styling inspired by Italy's Pinanfa-rina, it provided the performance of the roadster with the comfort of a sedan.

British Leyland, MG's parent, after struggling for two years with the poor-selling MGC powered by an Austin 3.0-litre six, thought a better bet for power and performance might be the GT with a Daimler V-8. It didn't get past the prototype stage.

This didn't deter privateer Ken Costello, an engineer who operated Costello Motor Engineering in Kent, from doing his own experiments. He was particularly impressed by the quietness, power and light weight of Rover's 3.5-litre V-8.

The overhead-valve aluminum V-8 had been designed by General Motors and introduced in the 1961 Buick Special and Oldsmobile F-85 intermediates. But GM soon realized a cast-iron V-6 was cheaper to build and offered about the same performance, so it sold the little V-8 to the Rover Co., who used it in Rover cars and Land Rover/Range Rover utility vehicles. It would also power the Morgan Plus-8 and Triumph TR8.

In 1970, Costello bought a V-8 engine from Rover and fitted it to an MGB GT to create his own MGB GT V-8. The performance, as expected, was outstanding, and even though Costello did almost no advertising, his shop was soon turning out GT V-8s at the rate of about one a week. A bonus was that the V-8 engine was actually lighter than the 1.8-litre MG four.

Naturally, this soon came to the attention of British Leyland, the corporate home of Rover and MG. They were a little embarrassed that Costello had been successful in doing what they had abandoned. They evaluated Costello's GT V-8, and then ordered their engineers to begin experimenting with the Rover V-8 in the GT. At the same time, perhaps not surprisingly, Costello's source of new V-8s began to dry up, but the resourceful engineer was able to scrounge enough used ones for rebuilding to keep his MGB GT V-8s going for two more years.

MG engineers modified the V-8 as required to fit into the smaller space, including designing revised exhaust and intake manifolds that placed the twin SU carburetors at the rear of the engine. The fit under the GT hood was so tight that small circles had to be cut out of the hood's insulating pad to accommodate the tops of the carburetors.

Power went through a four-speed all-synchromesh manual transmission fitted with an electric overdrive that operated on fourth gear. This gave a long-legged overall gear ratio of 2.52: 1, requiring the engine to turn a lazy 2,100 r.p.m. at 96 km/h.

Suspension was the usual MGB A-arms with front coil springs, and leaf springs with solid axle at the rear. Steering was by rack-and-pinion.

BL introduced the MGB GT V-8 in 1973, and the only external differences from the four-cylinder model were alloy wheels, larger tires and V-8 badg-ing. Performance of the 1,086 kilogram hatchback was sensational, as would be expected with the horsepower increased from 79 to 131. Even more important, the torque was increased from 94 to 185 lb.-ft. Britain's Motor magazine reported zero to 96 km/h in 7.7 seconds and a top speed of 200 km/h.

While impressed with the outstanding performance, the testers felt the aging design lacked refinement.

The handling, style and dash of an English sports car wedded to smooth American V-8 power would likely have enjoyed popularity in North America, but the GT V-8 was not imported because BL considered the cost of meeting safety and emissions legislation prohibitive. The MG GT V-8 was manufactured from 1973 to 1976, with a total of 2,591 built. Production would no doubt have been higher except for a relatively high price, and a chassis that was becoming dated.

It was another example of combining American power with an English chassis in the tradition of cars like Hudson Railtons and Cadillac Allards. A few have reached North America.

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