Background
It wasn’t lost on Ken Costello, engineer and championship winning touring car ace, that the MGB GT’s engine bay was on the roomy side. Indeed it had been designed to accommodate a V4 engine of an in house design before the NMC cost reduction police got wind of the idea. Whilst at a friend’s workshop, Ken was drawn to a compact looking V8 engine sitting on the bench awaiting repair. Despite its generous 3.5L capacity Ken was impressed to find he could almost lift the alloy V8 singlehandedly. The engine turned out to be the now iconic, Buick derived Rover V8 unit which first came to prominence for its transformational effect on the Rover P5 of 1967.
With the burly V8 being essentially no heavier than the MGB’s standard B-series unit, Ken could immediately see its potential for the MGB GT. This would mean that, unlike the 3-litre MGC, the balance of the car wouldn’t be seriously compromised by the fitting of a decidedly more sports car appropriate motor. Costello was soon marketing his own V8 equipped version of the MG which was very well received. So much so that Charles Griffin, then Director of Engineering for British Leyland, wrote to Costello requesting a viewing and a drive of his muscular MG. He was obviously impressed as by August 1973 an official Abington produced MGB GT V8 hit the streets. Concurrently BL also cut off Costello’s engine supply but not before something in the region of 225 units were thought to, ultimately, have left his workshops.
British Leyland had opted to use a mildly tuned version of the 3.5L V8 with a lower compression ratio and breathing through twin SU HIF6 carburettors. In this trim power was originally quoted at around 135bhp. The key metric, however, was the impressive 193 Ib-ft of torque at a sensible 2,900rpm. This transformed the car’s driving dynamics, especially compared to the somewhat asthmatic B-series powered cars. Contemporary road tests recorded a 127mph top speed and a 0-60mph time of 7.7 seconds. The standing quarter mile was achieved in less than 16 seconds. For the first time in the car’s history, the MGB GT could now compete on equal terms with contemporaries like the Porsche 911T and Datsun’s 240Z. Around the time of the launch, however, the repercussions of the OPEC oil embargo were starting to be widely felt. This helped to tarnish the appeal of big V8 engine cars despite the MGB GT V8 being virtually as fuel efficient as its lesser endowed sibling. The car ceased production in 1976. During this three year production window a total of just 1,839 chrome bumpered cars were produced and only 742 with the later, US-mandated rubber bumpers.








