FERRARI 330 P-4. Ferrari shrugged off Ford's massive Le Mans bid in '64 and '65 in spite

Ferrari shrugged off Ford's massive Le Mans bid in '64 and '65 in spite of operating on a significantly smaller budget: experience was its wealth. By 1966 Ford had banked sufficient experience through its win at all costs policy. But Ferrari didn't give up and, as John Allen explains, even came back in 1967 with the beautiful P4.

In some ways the Ferrari 330P4 repre-sented the end of an era. It first saw the light of day in 1967, yet it was a direct develop-ment of one of the earliest mid-engined sports cars, the 1963 Ferrari 250P, and it was essentially an outdated vehicle which was having to pit itself against much more modern opposition. That it fared as well as it did was more a tribute to the years of experience which Ferrari had amassed, than to any fundamental attributes of the car itself. Ferrari approached the 1967 season with nothing really new in its armoury. Ford, on the other hand, was in the process of going ultra-modern with its aluminium honey-comb monocoque J-car/Mark IV, Chaparral was dabbling with the advanced technology of wings and automatic transmissions, and Lola was about to unveil its sports-racing version of the previously Group Seven-only T70, another aluminium mono-coque. Ferrari's answer to the new wave challenge was to update the existing 330P3, and rechristen it 330P4. In its principal form, as a Group Six sports-prototype, the 330P4 had only one season in which to prove itself, for like so many other cars it fell victim to the CSI axe which cut it down at the close of 1967. During that year the Ferrari works team raced the 330P4 at only six circuits, these being Daytona, Monza, Spa, the Targa Florio, Le Mans and Brands Hatch; two victories were obtained, at Daytona and Monza, but the important race, Le Mans, fell to the Ford Mark IV, which took two wins from the only two races entered.

Nevertheless, the 330P4's fine showing throughout the sea-son was good enough (just) to hand the Sports Car Championship to Ferrari, which beat Porsche by 34 points to 32. Usually referred to by the abbreviated version of its name, the P4 had descended from the 250P by way of the 275P and 330P of 1964, the 275P2 and 330P2 1965, and the 330P3 of 1966. It used the same basic method of construction - a steel tubular chassis - although on P3 and P4 this was stiffened by the addition of aluminium pan-els, in addition to the fibreglass ones as used on earlier cars. The P3 and P4 chas-sis were substantially lighter than that of the P2 (perhaps by as much as a third) thanks to the use of lighter-gauge tubing. Suspen-sion of the P3 and P4 was also similar to that of the P2, which was the first Ferrari to use the then modern Formula One type, includ-ing trailing arms, but again the P3 and P4 benefitted from the use of lighter compo-nents. Shock-absorbers on the P3 were of steel, and non-adjustable, but those of the P4 were both lighter (aluminium) and also adjustable. The most dramatic changes which oc-curred during the P4's evolution from the 250P were those of shape, for the mid-Sixties saw the start of a revolution in aero-dynamics. Thanks to rule changes, and the 1966 introduction of a revised Appendix J which permitted sports cars to have narrower cockpits than previously, the P4, and the visually almost identical P3, become great cars to beat.

The P4 essentially followed the shape of the Drogo-bodied P3, but featured this wrap-around rear spoiler. 1967 was the year of the Chaparral high wing car.

significantly slimmer and sleeker than their immediate ancestors; even so, it appears that none of these cars had the right shape to go really fast. One of the most revealing sources of aerodynamic information is the Le Mans speed trap, a radar system which sits at the side of the Mulsanne Straight and tells the truth - or at least, as close to the truth as anyone is likely to get - about which is the fastest of them all. Conditions change from year to year, as does the radar, but for any given year comparisons between cars ought to be valid. The P4 does not emerge well from the data obtained at Le Mans in 1967: the three works P4s, each with some 450bhp on tap, recorded maxima of 192.6, 189.5 and 192.6 mph, whilst a fourth P4, nominally an Equipe Nationale Beige entry, was measured at 192.0mph; the average of the maxima for the four cars comes out at 191.7mph. Ford's works Mark IVs, the chief adversaries of the Ferraris, presented much more respectable figures, ranging from 206.9mph. The advantage of nearly nineteen miles per hour could not all be due to the Fords' greater power (reputedly 500bhp), but was also the result of a much better shape.

Differences between the shapes of the Drogo-bodied P3 and the P4 relate to de-tails only. For example, the pedal box on the P3, which had intruded into the radiator air outlet on that model, was reversed on the P4, allowing the air outlet to be larger front-to-back, and so aid airflow. At the extreme front of the car, the lower head-lights were raised slightly and positioned a little further forward, allowing more space for canard fins to be fitted. At the back, the P4 featured a full width spoiler as on the P3, but with extensions which wrapped around to the sides of the car. Both fixed-head coupe and open spyder bodywork was available, the two styles being interchange-able, with the open version (lighter by some 40kg) favoured for slow circuits where aero-dynamics were of lesser importance. Just as the P4's shape differed only slightly from that of the P3, the changes under the skin were relatively minor, with one exception. Whilst the P3 had two valves per cylinder, the heads of the P4 were endowed with three per cylinder, one exhaust and two inlet. The revised valve layout necessitated modifications to the tuned exhaust system to suit the changed characteristics of the classic V12, and experiments were carried out with balance pipes which linked the cylinders on the two sides of the engine. The P4 made use of the same basic en-gine design as its predecessors, although the 250P of 1963 and the 330P4 of 1967 had virtually no parts in common. The overall capacity of the dry-sump 4-cam V12 remained unchanged from the P3 at 3967cc (77mm bore and 71mm stroke), but

the claimed power output was up by some 30bhp.

Lucas fuel injection was fitted, as on the P3, but at the same time Ferrari pro-duced a carburetted version of the old two-valve engine, for use in a customer-car version of the P4, these being converted P3s, renamed as 412Ps (although at the time everyone called them 330P3/4s). The engine of the P4 was used as a partially-stressed part of the structure, but the posi-tions of the twelve mounting points differed slightly from those on the 412P; thus, a P4 engine cannot be dropped into a 412P without there being modifications made to the chassis of the latter. Other mechanical improvements over the P3 were equally small. The wheels, which on the P3 had been Dunlop light alloys with small rectangular holes, were replaced by Campagnolo magnesium castings with a five-pointed star design. These were wider than before, with the result that the rear wheels (at 11.5 inches up by two inches over those of the P3) in particular were deeply dished, requiring knock-off spinners with ears angled well out from the wheel centres. Tyres were Firestone, replacing the Dunlops which had previously been used by works Ferraris. The Girling brakes, with four-pot calipers, were outboard, unlike the three-pot brakes on early P3s, this making disc-changes easier; here, Ferrari was learning from Ford. During 1966 Maranello had been developing its own new gearbox, capable of accepting the torque of the 4-litre engine, but this was not ready in time for the P3, which had instead been fitted with a 5DS25, a proprietory 'box by ZF. By the end of 1966 the new five-speed synchromesh Ferrari gearbox was ready, and was fitted into the P4. As was standard practice for Ferrari, two gear sets were available, a "Targa-Florio" group with four low ratios plus a high fifth, and a normal set, with all five ratios being fairly evenly spaced. A useful improvement to the cooling sys-tem was the incorporation of a valve which shut off the header tank from the rest of the system; this permitted water to be added to the header tank even when the engine was hot, removing the risk of the pressurised system blowing hot water out as soon as the pressure cap was released.

The engine oil-cooler was an unusual device, an expen-sive coiled and finned tube nicknamed ser-pente and installed behind the water radia-tor. Fuel was housed in twin bag-tanks, one on each side of the car, and containing a total of 140 litres. A cross-over tube (actu-ally part of the chassis structure) linked the two tanks, and enabled both to be filled from either of the two fillers, and also allowed fuel to be drawn off from both tanks without the need to switch from one to the other. Rac-ing in wet weather brought to light problems with windscreen wiper motors, the original Lucas units used by the first P4s and 412Ps falling during the downpour at Spa, in 1967; as a result, the Lucas motors were replaced with Marelli units. After its career as a contender in the Sports Car Championship ended, the P4 was adapted as a Can-Am car, two ex-amples of the type being cut down to spyder configuration, with low-height windscreen, engine enlarged to 4.2-litres, and with re-vised aerodynamics both at front and rear. The cars were too heavy and too under-powered to provide any serious opposition to existing dedicated Can-Am cars, and they failed to shine in their new role. The original tube-frame P-series was at the limit of its development by the end of the 1967 season, and it is interesting to note that when Ferrari rejoined sports-car racing, at the beginning of 1969, the car which it used still featured a tube-frame chassis, but with so much reinforcement by stressed alloy skinning that it was virtually a semi - monocoque.