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The Cosworth YB has been fitted to all manner of cars over the years — these are four that almost made it into series production.

cosworth yb

Puma Concept

When Boreham lost the World Rally Car design and operating contract to M-Sport in 1997, at very short notice, it came as a shock, which left Philip Dunabin’s tiny World Rally Championship design team looking for something to do. The medium-term result was that Philip, aided enthusiastically by his associate Terry Bradley, and with Peter Bennett also closely involved, designed and developed the Puma Racing model, but the first fruits of their labour (produced with a tiny budget, and with styling help at a late stage from Design at Dunton) was the exciting one-off — the Puma Concept.

Externally the Puma Concept, revealed at the Autosport Show in the NEC in January 1998, looked like a normal Puma on steroids, for it featured expanded front and rear wings, a different front moulding, bonnet vents and a massive rear spoiler. Under the skin, however, it featured a slightly shortened Escort RS Cosworth platform and running gear (the Escort RS Cosworth had recently been discontinued), with north-south mounting of the engine, and a driveline which naturally included four-wheel-drive and a 224 bhp YBP version of the famous turbocharged engine. 

Unhappily, only one single car, with a startlingly-attractive colour scheme, was ever built, and never competed in an event, though the Puma Racing which followed used the same style (but not the mechanical package) of that original. 

Panther Solo

Set up in the 1970s, Panther was originally a British coachbuilding company before it sold out to a South Korean businessman, who eventually sold it on to the Korean car-maker SsangYong. In the meantime the business was moved into a new factory in Harlow New Town, and the XR3i-engined Solo 1 prototype was designed.

This car did not go into production, and was replaced by the Solo 2, which was a mid-engined four-wheel-drive machine, powered by a 204 bhp Cosworth YB engine, to which a Borg Warner T5 gearbox (of Sierra RS Cosworth type) was mated, and allied to a modified version of the Sierra XR4x4 four-wheel-drive transmission. Although some of Ford’s SVE specialists were consulted, behind the scenes, much of the four-wheel-drive installation was engineered by FF Developments of Coventry. Cramped two-plus-two seating was incorporated in an FHC layout, the styling having been carried out by Ken Greenley.

The structure was a mixture of innovation (a spaceframe chassis and some composite elements, allied to an aluminium honeycomb/glass-fibre bodyshell), and Ford parts bin engineering (which included Escort front struts and ABS from the Scorpio. The engine/transmission layout was back to front, with what would normally be considered the front of the YBB engine at the back of the car, pointing rearwards!

Although road tests gushed over the Solo’s brilliant handling, there were complaints about the noise and a surprising lack of performance, with 0-60 mph in at least seven seconds. The original prototype, still not complete, was introduced in September 1987, but the very first hand-built cars were not delivered until 1989, but sales were painfully slow (the original retail price of £39,850 cannot have helped) and in the end the company pulled the plug in 1990, shortly withdrawing completely from the British marketplace. Total production is not clear, but was certainly not more than 25 in all.

cosworth yb

The RS200

We all know that the Group B RS200 was powered by a turbocharged BDT engine — 1.8-litres on all the cars which were sold and/or rallied, and 2.1-litres with the ultra-special Brian Hart engine derivative which followed for rallycross use in 1987. It is not generally known, however, that there might have been a successor which would have been powered by a Cosworth YB engine instead.

John Wheeler, who was mainly responsible for the original engineering of the RS200, recalls that in 1986 (and following the Group B accidents which sickened so many enthusiasts) the FIA suggested that a less powerful derivative of Group B should follow. It was with this in mind that Boreham considered re-engineering the RS200 in ‘evolution’, retaining the existing four-wheel-drive layout, but with a Cosworth YB behind the seats instead of the existing BDT.

cosworth yb

As it happens, no such car was built at the time, however  more recently such a machine has been produced. With a modified and more sturdy chassis/tub/subframe structure, and with a 400 bhp version of the YB engine fitted in place of the BDT, this is a single car created by John Wheeler for his own use. That car appears occasionally at classic rallying events, with John himself driving. As one might expect from this meticulous engineer, the car always looks immaculate, sounding and going well, too!

4wd Sierra Three-door

Way back in 1988, when the Sapphire Cosworth saloon was launched, it was clear that a four-wheel-drive derivative (which became the Sapphire Cosworth 4×4) would succeed it in 1990. However, Boreham was anxious to start development of the four-wheel-drive car as soon as possible, especially as they had to sort out the development details of the new MT75 gearbox, and of the motorsport-only seven-speed MS90 transmission, too.

Accordingly, in 1989, Boreham (along with Gordon Spooner Engineering) produced an intriguing, impressive (and, for the time being, very secret indeed) four-wheel-drive prototype, which not only used the latest 350 bhp Mountune version of the YBM, but combined the existing original whale-tail Sierra RS Cosworth three door cabin with the front-end of the Sapphire!

The car chosen for this work carried the registration number D373 TAR, which was that of a genuine works rally car which had been used extensively throughout 1987 and 1988 — notably in Finland in 1987 (with Texaco livery) where Ari Vatanen had taken second place overall. Its final official appearance had been in the 1988 RAC rally, where Carlos Sainz finished seventh, and most of that car’s structure was used as the basis of the unique 1989 prototype. 

This car was both lighter and apparently more nimble than the four-door Sierra Cosworth which was to follow, but although Boreham’s Mike Moreton begged and pleaded with Ford Product Planning for approval, they refused to approve that this hybrid could go even into limited-run production, so this prototype became one of a kind, and has now been scrapped.

A Six-Cylinder Cosworth YB

Two cars influenced a tentative proposal to develop a straight-six derivative of the YB engine — one being the projected Aston Martin DB7 (at that point still known as the DP1999) of 1990, the other being the short-lived Vauxhall Lotus-Carlton/Opel Lotus-Omega, which was being manufactured at the Lotus factory at Hethel in Norfolk. 

The idea of developing a turbocharged 3-litre six to power Ford-promoted cars to compete with such opposition, one which could produce at least 300 bhp, was intriguing, to say the least. 

The Lotus Carlton, which appeared in 1989, had a 3.6-litre twin-cam six-cylinder engine which produced 377 bhp, and delivered a top speed of 176 mph. Ford briefly considered letting Cosworth go ahead to help them to match that, but went no further than carrying out paper studies.

The second influence was more credible. Ford had bought Aston Martin in 1987, and by 1990 Rod Mansfield, famous for founding and developing Ford’s Special Vehicle Engineering department in the 1980s, had become its technical director, and restarted the DB7 project. Encouraged by Aston Martin chairman Walter Hayes, Mansfield and Paul Fricker then dabbled with the idea of making a YB6 engine to suit such a car.

To quote Fricker: “I did mock-up a six-cylinder version one day, where I cut-and-shut a couple of engines. We never actually ran an engine… but a turbo-straight six would have made a very nice car. We would have made them in-house, but the numbers might have been tiny.”

Later he admitted that the investment needed to produce a brand-new cylinder block and crankshaft, would probably have killed it off in any case.

Words Graham Robson

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