Ford - Weslake V12

The Blue Oval's investment in Cosworth's DFV was repaid many times over. But Ford didn't always hit the jackpot. Keith Howard tells the story of an engine that met all its design criteria, yet which still proved an embarrassment to its paymasters

Aesthetically, Rye Harbour is a million miles from its parent town. Whereas mediaeval Rye, perched high on a nearby hill, is cobbled streets, sagging timber-framed buildings and cake-laden tea shops, Rye Harbour is a bluff industrial adjunct with no facilities for charabancs. It is difficult nonetheless to imagine this East Sussex backwater being home to not one, but two Formula One engine projects, both undertaken at Weslake & Co Ltd, Harbour Road.

The more famous of the two, and in some respects progenitor of the second, was the Weslake V12 built for Dan Gurney's Eagle F1 team. Introduced in the same year as the epochal Cosworth DFV, it scored only one GP win in the back of the circling Eagle at Spa in 1967, but considering the modest resources available to Gurney's team, it was generally acknowledged a worthy effort. Engine number two, the Ford-Weslake, was a different story.

For a start, F1 was not supposed to be its prime focus. When Harry Weslake, Ford's motorsport director Stuart Turner and GT40 designer Len Bailey bumped into each other following the 1970 British GP and hatched the new venture, Ford didn't need a successful F1 engine, because it already had one in the DFV. But many were interested in using the Cosworth engine for sportscar racing, a diversification which designer Keith Duckworth opposed with his characteristic forthrightness. A Weslake-designed, Ford-badged V12, specifically for endurance events, would plug that gap and understudy the DFV should its performance in F1 falter.

The deal between Weslake, Ford's Walter Hayes and legendary sportscar team manager John Wyer, then running Gulf's racing outfit, was this: Weslake would develop the engine, Ford would buy it from him, and Wyer's men would be allowed initial use of it, just as Lotus had been with the DFV. If the first engine sold to JWA did not meet specified performance criteria then Ford would be obliged to buy it back at the original price.

Despite having the same cylinder dimensions (75 x 56.5mm) and crank arrangement as the Eagle unit, Weslake's new 2995cc V12 was substantially different otherwise. The aluminium-alloy block, which was designed to allow a bore increase up to 80mm, was unusually strong to withstand the rigours of 24-hour racing. A cast magnesium sump added to its stiffness and was cross-bolted to the caps of the five main bearings, which were downsized relative to previous Weslake designs to reduce weight and friction. In common with the DFV, the cast aluminium heads had a narrow included valve angle and pent-roof combustion chambers, but incorporated Weslake's trademark swirl-inducing lobes. Compression was "about 12:1".

Including the integral clutch housing, the engine measured 31.7in long, 19.1in wide and 22in high (80.4 x 48.5 x 55.9cm) and weighed 3851b (175kg) with flywheel and starter motor.

It ran on the Rye dyno for the first time on 20 December 1971, recording a peak power of 450bhp, compared with 451bhp for a DFV on the same rig. After a little development, the new V12 was soon delivering well over 460bhp.

Relations between Weslake, Ford and JWA remained good into 1972, and the V12 duly passed its acceptance tests. But things began to sour later that year as a result of Weslake's determination to push the engine into F1. On 20 September, Turner wrote to him: "...quite clearly the V12 project seems to be getting into a tangle. The unfavourable publicity which has recently appeared in the sporting press did none of us any good..."

The incident to which Turner was referring was a disastrous test of the V12 in the back of a Brabharn BT39 at Silverstone, with Graham Hill driving, news of which had leaked. Worse would follow in 1973.

When the Ford-Weslake raced for the first – and only time – in the Gulf-Mirage M6 at Daytona, both cars broke during practice, as did the one car entered for the race. For the Le Mans test weekend, Gulf-Mirage arrived with one M6 fitted with a DFV, driven by Ganley, and a second with the V12, driven by Derek Bell. Bell's best lap was almost 16sec slower.

Although these events paint the Ford-Weslake as a washout, the truth is more complex.

Gordon Murray, who drew the BT39 conversion, admits: "It wasn't a fair test of the engine because the car was so awful, a lash-up. Graham said it was just diabolical."

The Daytona fiasco, says Michael Daniel – Weslake's stepson and designer of the V12's block – was entirely due to a JWA cock-up over gear ratios.

And the Le Mans test? All down to the untried coupé body in which the V12 was fitted, recalls Bell, who remembers testing otherwise identical M6s with the V12 and DFV at Silverstone back-to-back and there being little to choose between them.

Turner admits it was a relief when, in the aftermath of the first oil crisis of 1973, Ford's motorsport budget was slashed and support for the V12 perished as an inevitable result. Ford had pumped £39,000 into the project with little to show for it. But that was but a quarter of the £150,000 Weslake claimed to have spent

Determined to recoup some of the shortfall, it began a legal action against JWA which, had the latter not settled for an undisclosed sum, would have seen the two companies tearing into each other in the High Court in London, furthering Ford's discomfiture. As part of that action a V12 – the sixth and last – was independently tested at Swindon Racing Engines and proved itself capable of 464bhp at 10,750rpm, thereby vindicating Weslake's claims.

The final act in the tragedy came when, to prevent Harry squandering more money on it, Michael Daniel, then Weslake's MD, sold the V12 project – drawings, patterns, everything – to Terry Hoyle for £10,000. It was that, Daniel reasoned, or the company going under.

And so Harry never realised his dream of building an F1 engine to oust the DFV. He died four years later, in 1978, at Wembley Stadium, watching his 'bike engines power the bulk of the competitors in the world speedway final.