Background
Back street mechanics have something of a bad reputation, but if it wasn’t for one from Kent, the MGB V8 may well never have existed. Ken Costello’s Sidcup workshop was his usual base but while at Monza, working as a driver on the movie Grand Prix, he visited a museum and spotted a Maserati V8. Its compact packaging got him thinking and his thoughts turned to the rather less exotic GM V8 that Rover had bought the rights to in 1965. More on this, and how the MGB and the all alloy V8 got married, later on.
Further back, in the 1950s MG was already working on a replacement to the highly successful MGA, and prototype development was completed early in the next decade, leading to the new model’s launch in 1962.
The MGB looks like a more modern version of the MGA and that’s exactly what it is. The handsome looks are built around a monocoque bodyshell, with the MGA’s separate chassis construction binned in favour of this stronger, lighter design.
However, the rest of the car was remarkably similar – after all, it’d sold like hot cakes so why change a winning formular? The BMC B-Series engine had now grown to 1798cc but retained the twin SU carburettors of the earlier car, and now made a healthy 95bhp. I say healthy because at the time it’s performance was good enough, although it was never a particularly fast car.
A four-speed manual gearbox with synchromesh on the top three gears was again carried over from the earlier car, as was the option of an overdrive unit operating on third and fourth, and its output fed a live axle supported on cart springs. That non-synchro first gear was replaced by an all-synchro box in 1967.
Front disc brakes were standard from the off and other than luxurious wind-up windows and a crackle black dashboard rather than the MGA’s body coloured part, an MGA owner would feel at home behind the wheel of the new model.
In 1965 MG introduced the Pininfarina styled MGB GT coupé with a jaunty hatchback and taller windscreen, a redesign that worked far better than some other maker’s attempts to build a coupé from a roadster. But many people, including our hero Ken Costello, wanted more from their MGBs.
The problem with fitting large engines into cars not designed for them is often that the extra weight upsets the handling. But Costello realised that the Buick/British Leyland alloy V8 engine was lighter than the original iron B Series four cylinder units – a full 40lb lighter. He then wondered whether the V8 could be installed into an MGB without extensive modification.
Given that the gearbox and rear axle had been upgraded in the second series of four cylinder MGB’s to the same specification as the three litre MGC, the transmission was going to be able to withstand the forces imposed on it by an only slightly larger V8. On a visit to Piper’s Garage located in Hayes, Kent, Ken Costello came across a Rover V8 on the workshop floor and it got him thinking.
Over at British Leyland, management had thought of installing the V8 into an MGB, and engineering had been tasked with assessing the idea, but they had advised that it couldn’t be done without widening the MGB by 3.5 inches.
Ken Costello didn’t agree, and he figured out that the V8 engine could be installed into the existing MGB with little modification. He managed to borrow a nice red MGB from a trusting friend, and he bought an Oldsmobile 215 aluminium V8 (which was based on the same Buick alloy V8 that British Leyland had acquired the rights to manufacture and were fitting into Rover P5bs) and proceeded to engage in some creative engineering. It took six months of work to get the whole project complete but it became quickly obvious that this was a great idea. Costello had a car up and running reliably in 1969.
This finally got BL to up their game, although it took them four more years of faffing before they finally launched their own MGB GT V8 in 1973, just in time for the fuel crisis prompted by the Yom Kippur War. Not only did their timing stink, they also used a detuned version of the 3.5-litre engine as fitted to the Range Rover, whereas Costello’s cars, which he’d sold in some numbers, employed a full fat 180bhp spec version.
Nonetheless, buyers who wanted a factory built MGB V8 were now satisfied – almost. For reasons best known to themselves, BL never built a roadster version of their V8 powered car, claiming the open top shell couldn’t take the power. This was never true of course – the MGB was designed as an open top car from day one, and the 1000s of V8 powered roadsters built by specialists and enthusiasts over the last 50 years prove the concept, as did BL itself when they happily stuck very heavy six pot engines into roadster shells to create the MGC. But how is this car a ‘factory MGB V8?’
