Power without glory

Coventry-Climax eventually wrote its name large in the Formula One annals via its hugely successful associations with Cooper and Lotus. But in 1954, the Midlands firm produced a unit that might have threatened Mercedes. Keith Howard reports

Has there ever been a less appropriate nickname for a racing engine than that bestowed upon the Coventry-Climax FPE – or `Godiva’? By rights, it ought to have been Wally Hassan and Harry Mundy’s first F1 power plant. But whereas Lady Godiva famously rode naked through Coventry’s market place to persuade husband Leofric, Earl of Mercia, to reduce the taxes (unlike modem reenactments, where long blonde hair is often strategically placed, Godiva had hers tied up behind her head), the engine that bore her name was reticent to the point of invisibility. In fact, it never bared itself to examination on the racetrack; at least, not at the time it was designed.

What kept this `Godiva’ at home was an unwarranted inferiority complex. Having designed, built and developed the engine to a point where it was ready to go, Hassan and Mundy allowed themselves to be dissuaded by the inflated power claims of their competitors – claims which had more to do with braggadocio and wishful thinking than results on the dyno. Thus the Godiva became an early victim of F1 spin and was never put into production.

Best known for its fire pumps, industrial engines and forklifts, Coventry-Climax Ltd was not an obvious source of racing engines. But it had three human assets that were to turn it into one of the successful engine suppliers of the latter half of the 1950s and first half of the 1960s.

The first two of these were Hassan and Mundy, whose credentials included design of the Jaguar XK straight-six engine (Hassan) and a close involvement with the BRM V16 project (Mundy). The third key player was their boss Leonard Lee, a man who Hassan described in his autobiography as ‘a great patriot who liked to see the county performing well in motorsport.’

All this talent and enthusiasm notwithstanding, motivation for the FPE was external. Anxious to have a competitive, British-built engine to power their cars under the new 2.5-litre formula of 1954, HWM, Kieft, Connaught and Cooper made a joint approach to Lee to ask him to fund a Hassan/Mundy design. By autumn 1952, Lee was persuaded and gave Hassan the go-ahead to begin work on what was internally designated the Fire Pump Engine, so as to disguise its true nature from those who might disapprove of this diversification.

The FPE’s ‘Godiva’ soubriquet, derived from Coventry-Climax’s company badge which featured an image of the city’s famous nude, was also external. Because the name had already been applied to a range of pre-WWII trailer-mounted and portable fire pumps, it was never officially sanctioned.

Hassan and Mundy quickly agreed on the FPE’s essential features. It would be a 90-degree, quad-cam V8 with five main bearings and oversquare cylinder dimensions of 76.2×67.94mm, giving a total swept volume of 2479cc. Most of its design features followed familiar racing practice, although it began life with hairpin valve springs (something Mundy may have imported from the BRM V16) despite a modest max engine speed of 8500rpm. Although valve springs of this type had been used for many years in racing motorcycles, and were successfully employed by Ferrari, they proved prone to breakage in the FPE and were eventually replaced with conventional helical types.

The two designers aimed for an initial specific output of 100bhp per litre, expecting this to make the engine immediately competitive with Ferrari and Maserati. Key development issues proved to be the firing order, fuelling system and exhaust arrangement. In an attempt to quell crankshaft torsional resonances, the first development engine fired its cylinder banks consecutively as two in-line fours, but this was found to generate unfavourable pressure pulses in both the inlet and exhaust. Unburnt fuel would sometimes shoot out of the engine inlets, almost to the test cell roof, a situation which – as Hassan – observed was good for neither power nor fuel consumption. Reverting to a conventional V8 firing order solved the problem.

Nothing was known at the time about optimising V8 cylinder extraction by cross-linking the exhaust systems of each bank, so exhaust manifolding proved to be a headache. Eventually, separate exhaust stubs were used for each cylinder, an arrangement which gave good peak power but not the best torque characteristic.

At the other end of the engine, twin-choke Solex carburettors were used initially, then Webers, but the best results were obtained using SU fuel injection. Like all injection systems of the time it was crude, but in combination with an alcohol fuel blend supplied by Shell it helped the FPE eventually achieve 264bhp at 8500rpm.

Had Hassan and Mundy only known it, that was more than enough to make the FPE the most powerful F1 engine of 1954. But rumours of the superior outputs being achieved elsewhere, and an abiding concem that the hill-and-dale profile of the FPE’s torque curve would make it all but undriveable, persuaded them not to let it beyond the factory gates. The hopefuls at HWM, Kieft, Connaught and Cooper, whose idea it had been, never got a sniff of it, even though Connaught and Kieft had built cars in anticipation.

Although the Godiva never raced at the time, it did compete eventually. The entire project was sold to Andrew Getley in the mid-1960s, with the proviso that he remove the Coventry-Climax name from the cam covers. Paul Emery and Hugh Aidan-Jones increased the capacity of one of Getley’s engines to three litres, fitted it into the back of an F3 chassis, called the resulting car the Shannon, and hired Trevor Taylor to race it in the 1966 British GP at Brands Hatch. It qualified 18th and lasted only one lap before retiring with a fuel problem.

More recently, the Godiva has run again, in mildly modified 2.5-litre form, in Bill Morris’s reconstructed Kieft GP car. Now we may at last be able to judge how much shine the FPE might have taken off Mercedes’ triumphant return to GP racing in 1954 had Hassan and Mundy only kept faith.