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Evolution of the Costello V8

Developments of the Costello Engine Bay

The following four photographs show how Ken changed induction designs on most of the original Rover and Buick units. First came the Mk I 3500cc carburetted version (with twin SUs, below far left), built in 1971, as in Lawrence Wood's original roadster engine, initially registered the previous year. Perhaps about 50 Mk Is were made, with about half of them being GTs and the other half roadsters. All had the distinctive bulging bonnet.

They were followed by the Mk II 3500cc carburetted version (with single side-draft Weber, below, second from left), built in 1972, as seen in Harry Irvine's 1970 roadster. The distinctive bonnet had been phased out by then. The Mk IIs are the most plentiful of all Costellos.

Ken had several requests to describe the evolution of the Costello V8.

In his own words:

The first prototype MGB V8, fitted with a Rover P6 engine with a factory claimed output of 150 bhp, ran in late 1969. However, I am not alone in believing that the adoption of free-flowing inlet and exhaust manifolds probably liberated a further 10-15 horsepower. In order to provide clearance for the SU carburettors on the standard P6 'pent roof' manifold, the first car had a fabricated air scoop bulge on the bonnet (See picture in Articles: Sunday Times, July 25th, 1971 - LW). The distinctive eggbox bonnet arrived a little later, as did the much neater, sculpted glass fibre bonnet necessary to accommodate engines in the P6 format, and a few early Buick-derived engines equipped with Carter 4-barrel carburettors.


That distinctive Mk I bonnet bulge was deleted at around car 50, when a change to new, low-profile inlet manifolds offering the choice of twin SUs or a single twin-choke, side draft Weber rendered it redundant. Cars with P6 or Carter intake manifolds were often retro-fitted with a version of this low-profile intake system, and in the case of the P6 version, the original SUs were re-used. The egg crate grille disappeared the next year when it became obvious that series production would have to end and it was therefore pointless ordering another batch. The last few cars were delivered without them. In fact, a few customers specified that their cars should bear no outward signs of what they really were. Could this have been in anticipation of the pleasure to be had in surprising other motorists with an unexpected turn of speed?


However, back in 1970, the conversion had proved so successful in performance and engineering terms that I had decided to put it into production. The first fully productionised car (of around 225 made altogether) appeared in mid 1971 and was very favourably reviewed by the motoring press. (There are several contemporary road tests in the Articles section - LW).The writers saw it as much more than a just one-off special and it was produced in sufficient volume to be regarded as a marque in its own right. (Indeed, there are numerous famous marques from motoring history which have achieved that status despite having been produced in far fewer numbers than the Costello - LW)


As a result of those glowing press reviews, Charles Griffin, then Director of Engineering for British Leyland wrote to me expressing an interest in the car and asking to see it. He revealed that he had previously dismissed the idea of installing the company's V8 in an MGB as simply 'not feasible'. However, after a thorough examination and a road test of my car, he was obviously impressed by what had been achieved: 'This is a first class job,' he said. Subsequently, the Chairman, Lord Stokes, was equally impressed - BL's interest in their abandoned MGB V8 project was rekindled, and their initial offers to assist me in my own venture soon appeared to become an attempt to obstruct it. (See Articles: BritishV8 - LW).


The sump and engine mounts were actually produced, but the suspension was only fitted to a couple of cars in prototype form and the gearbox, though highly regarded, was, sadly, only made as several prototypes and a pre-production run of 25.

Initial development of the Costello V8 had involved a number of modifications to the base vehicle, including the re-shaping of the inner front wings, alterations to the lower steering column (involving a new splined shaft and a universal joint, both from the same company that then supplied Triumph) and bespoke 'block-hugging' exhaust manifolds - all in the interests of creating clearance for the engine. There were also special engine mounts and cooling arrangements, the fitting of an MGC 3.07: 1 crown wheel and pinion, a bell housing adapter, and internal modifications to the standard gearbox (locking out overdrive on third, which was not strong enough to take the torque of the V8 engine).


Meanwhile, development of the vehicle had continued with the introduction of a cast alloy inlet manifold carrying a rear-facing side draft Weber (which not only removed the necessity for a bonnet bulge, but also improved performance), a cast alloy sump and engine mounts, pattern-making and prototyping of a revised front suspension (which replaced the lever arms with upper wishbones and telescopic dampers) upgraded front brakes with ventilated discs and larger calipers - and my own, engineered from scratch, 5-speed gearbox. As I've indicated previously, the standard 'box wasn't really up to the new job behind a V8.


The sump and engine mounts were actually produced, but the suspension and brakes remained in prototype form and the gearbox, though highly regarded, was, sadly, only made as several prototypes and a pre-production run of 25.


By now, BL had produced its own, less powerful (137 bhp) version of my car and had effectively terminated my engine supply. I soldiered on, sourcing second hand Buick units from Belgium and rebuilding them with new parts, but this was never going to be a reliable or continuous supply. So that, together with the fuel crisis of 1973, put paid to Costello production (As the latter subsequently also did to the Leyland version).


With series car production over, development also came to a halt and all existing tooling and patterns were put into storage, though some parts (like the Weber inlet manifold) were later made in small numbers for retail sale. Apart from a few one-off V8s, I subsequently concentrated on other projects, mainly the gearbox. However, in the late eighties I was persuaded to produce a further small run of ten fuel-injected (Mk III) Costello V8s, which also incorporated my original suspension and braking upgrades. Local dealers were the source of 3.9 litre injected Range Rover V8 engines, several of which were further upgraded by Oblic Engineers of Royston. Injection development was carried out in conjunction with Roger Parker, now the technical guru for the MGOC.

I produced my own cast inlet plenums and modified inlet manifolds and a front brake conversion based on Austin Princess or Rover SD1 calipers. By then, Ron Hopkinson had introduced a fabricated front suspension conversion similar in concept to my own, and one of these was bought in for evaluation as it would have been a more economical way forward than exhuming my casting patterns and more or less starting from square one.


However, the Hopkinson conversion was not completely satisfactory, not least because at that stage it would not fit both chrome and rubber bumper cars. So I reverted to my own design in cast alloy, using slightly re-worked versions of the pre-existing patterns from '72/3. The brake and suspension upgrades (which included lower wishbones offering slightly increased camber) were available as options on the new injected cars and also as aftermarket conversions for the owners of original Costellos - and of other MGBs as well. The first car to be built incorporating all my developments was for the TV journalist Roger Cook (a previous Costello owner).


I had considered an independent rear suspension conversion, but had discarded the idea on the grounds that it either involved radical modifications to the original car or an unacceptably compromised suspension layout. It was also going to be very expensive to produce and install and would not have been the simple, bolt-on upgrade I have always favoured. I also believe that a properly located live rear axle on coil springs works better than a compromised independent set-up every time. The eventual result was the current 5-link system.


The outward appearance of the Mk III injected cars was left pretty much to the customer's choice, though my preference (as in Roger Cook's car) was to use a standard MGB honeycomb grille in which the plastic insert had been replaced by stainless steel mesh, and specially commissioned, 15" five spoke Revolution centre-lock wheels. Most owners, however, seem to have chosen the 'Q car' look and the more widely available Minilite or Minilite replica wheels. Under the bonnet was where the visual difference was obvious, with the finned, Costello-branded plenum chamber taking centre stage. Updated Costello badges were designed and several hand-made, but in the days before laser engraving (as used in the current, very good reproductions) they were prohibitively expensive to produce in limited numbers.


Frontline Costello of Bath still offer the latest iteration of my alloy front suspension conversion, an updated front brake upgrade using an alloy, four-piston caliper and the Frontline Costello bolt on, five-link, coil sprung rear suspension conversion mentioned above. All these products bring the MGB (and my story) pretty much up to date.


Ken Costello, August 2009.

The Mk III, 4200cc single-port fuel injected version (second from right) is from Brian Perry's Roadster. Approximately 10 Mk IIIs were built by Ken in the early 1990s.The 5000cc eight-port injection version (far right), from Roger Cook's Wildcat-engined GT, represents the most highly developed, and the most powerful of all the Costello conversions.

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