The Ferrari 312P Sports/Prototype

Making rules to govern sports-car racing is never an easy task, especially when Ferrari and Porsche give a “helping” hand and then play the game right up to the limit of the regulations. The classic sports-car races such as the Le Mans 24 Hour race and the Targa Florio are important races to win for any manufacturer of high performance cars, and the more recent classic events like the Sebring 12 Hours, the ADAC 1,000 kilometres at the Nurburgring or the Monza 1,000 kilometres are also important, as are the more recently introduced 1,000 kilometre races at Brands Hatch and the Osterreichring. All these events are motor races as distinct from driver races, which is why motor manufacturers like Ferrari, Porsche and Alfa Romeo are interested in winning them, and will play as close to the regulations as possible in their efforts to win.

It was the appearance of the 7-litre Ford Mk. IV and the 7-litre Chaparral-Chevrolet that really started the panic among the rule makers and caused the instant decision to limit engine capacity to 3-litres, ruling out all American-powered machines. It was then realised that people like Lola were being penalised, for the T70 was using a Chevrolet V8 in the production run of sports/racers, so another hasty decision said that if 25 cars were built they could be called sports cars and have 5-litre engines, otherwise they were prototypes and were limited to 3-litres, even if you built one or you built 24. Porsche promptly built 25 examples of their 917 coupes, for the rules forgot to say that you had to sell 25 examples, and Ferrari followed suit with his 5-litre 512S coupés, and in no time at all sports-car racing was back to square one with works teams of 5-litre Porsches racing against works teams of 5-litre Ferraris, and anyone foolish enough to build 3-litre prototype cars, like Matra and Alfa Romeo, were left behind. Porsche and Ferrari were not cheating, they were merely out to win and playing right up to the limit of the rules. This caused the rule makers to have another brainstorm and as from January 1st, 1972 there was an overall limit of 3-litres, except for GT cars and saloon cars. This was announced in 1970 so there was plenty of warning, and Porsche made it clear they were going to withdraw from free-for-all sports-car racing at the end of 1971 and Ferrari wasted no time in preparing for the new enforced 3-litre capacity limit. He dropped all development on the 5-litre V12 model and began a new era of sports-car development, using as a basis the horizontally-opposed 12-cylinder 3-litre engine of his Grand Prix car. The 312P was born and two prototypes were built for the beginning of the 1971 season. It was very obvious that they would be no match for the 5-litre Porsches that the Stuttgart firm were supplying to special customers, but Ferrari was not bothered. 1971 was to be an experimental season to develop the new 312P sports car ready for a complete sweep in 1972. In spite of numerous set-backs the plan went ahead and by the end of 1971 the 3-litre Prototype Ferrari was almost a match for the 917 Porsche, especially when fuel consumption and tyre-wear was taken into account. In 1972 Ferrari entered his 3-litre prototypes in every race except Le Mans, and won the lot. The 312P won the Argentine 1,000 km., the Daytona 6 Hours, the Sebring 12 Hours, the Monza 1,000 km., the Spa 1,000 km., the Nurburgring 1,000 km., the BOAC 1,000 km., the Austrian 1,000 km., the Watkins Glen 6 Hours, and the Targa Florio. By any standards it can be considered a very successful car and though the victories were achieved with the loss of material, and the opposition was feeble, it still takes a good car and a good team to win every race for which they enter.

In the Argentine 1,000 kilometre race in 1971 two brand new cars appeared and showed a good turn of speed, even against 5-litre opposition. In that race Ignazio Giunti was killed in the second of the cars, and it was never rebuilt. The first car was then used throughout the 1971 season as a one-off experimental machine and it led a very hectic life, being crashed at Brands Hatch, Spa and Osterreichring, and seldom lasting for long in any race, but nevertheless providing a lot of information for the 1972 season. At the end of 1971 a third car was built, using all the knowledge gained, and this was number one in a series that were laid down for the 1972 season. It appeared at the Kyalami 9 Hour race in South Africa, along with the much-rebuilt prototype car. For the 1972 season six more were built, and the object was to run three cars in each race in the Sports Car Championship, and ring the changes so that each trio of cars did not have to do two consecutive races. Apart from minor accidents involving rebuilding, this plan worked out and as far as was possible no car did two consecutive races. The driver team for this mammoth project comprised the Grand Prix trio of lckx, Regazzoni and Andretti, while Peterson, Schenken and Redman were co-opted from other Grand Prix teams, and Merzario was signed on as reserve and later Munari joined the team. The whole project was “master-minded” by team manager Peter Schetty, with two or three engineers, and chief engineer and designer Mauro Forghieri stayed at home to work on other projects. He had been very much in evidence at all the 1971 races, until the prototype was finalised and the pattern was set for 1972. The cars were numbered on even numbers only, starting with 0880 and running to 0896.

The heart of the car is undoubtedly the flat 12-cylinder engine, identical in construction to the Grand Prix engine, with opposed banks of six cylinders, each with two overhead camshafts, four valves per cylinder, with the inlet ports running down between the camshafts and the exhaust ports underneath. Bore and stroke are 78.5 x 51.5 mm. giving a capacity of 2,993 c.c. and 440 b.h.p. is developed at 10,800 r.p.m. (the Grand Prix engine running to 12,600 r.p.m., so it really is a de-tuned Grand Prix engine). The car has a tubular space-frame chassis with sheet aluminium rivetted to the tubes to form a semi-monocoque construction and behind the cockpit the tubes form a structure over the top of the engine, which is itself attached to the main frame at its front end and forms a central backbone for the car. The two seats are very close together in the middle of the car with wide sponsons on each side. There is nothing in the right-hand one, but the left-hand one contains the regulation 120-litre petrol tank. At the forward end of the right sponson is a huge filler-cap with an Avery-Hardoll bayonet-type neck, and this feeds into a large diameter pipe that runs across the floor of the cockpit, under the driver’s knees, and takes the fuel to the tank on the left. From the tank itself another filler neck protrudes, with a similar bayonet-fitting. The tank is on the left to counteract the weight of the driver, who sits on the right, and the filler cap is on the right because most of the pits are on that side on the right-hand circuits. To refuel, the large diameter gravity fed hose is plugged into the right-hand filler and a plastic container is clamped to the filler from the tank itself. The petrol flows across the transfer pipe and into the tank, expelling the air in the tank into the vented plastic container. When petrol flows up into the container it means the tank is full and removal of the feed pipe and the container from their bayonet fittings seals the system, the Avery-Hardoll connectors being self-sealing and are only open when locked into position by a twisting motion. As you turn them and unlock them they seal themselves automatically.

Water radiators are mounted at the rear of each side sponson, with ducting in the bodywork feeding air to them, and behind the left-hand radiator is the oil tank for the dry-sump lubrication system. An oil cooler for the engine is mounted across the top of the engine, just above the clutch housing. In the side of the oil tank, with a hole in the side of the car for access, is a “plug-in” filling attachment, rather like those used on air-lines, and oil from a pressurised cylinder is forced into the tank through this non-return valve. Behind the oil tank is a sight-glass tube to show the level and this is visible through a slot in the side panelling of the car. On the right-hand side of the car is a similar non-return valve for forcing water into the cooling system, if necessary, the normal filler and swirl-pot being in the headrest behind the driver’s seat. While the fibre-glass nose piece and tail of the body are red, and the sponsons are aluminium, the head-fairing, along with the rear spoiler and tail fins are coloured white, yellow, blue or green, for recognition purposes.

Suspension at the front is by double wishbones, the lower one very wide based, and orthodox coil-spring/damper units are used. The cast–alloy hub carriers extend rearwards to form steering arms, with the rack-and-pinion assembly passing above the driver’s knees, while an anti-roll bar is forward of the suspension, mounted on the front bulkhead. The disc brake calipers are mounted on the hub carriers, and the alloy wheels have pin-drive location with a single central locking nut. At the rear the hub-carriers incorporate the disc brake caliper and are hung on a lower wishbone, anchored at its apex on a casting, under the clutch housing and at the top by a single transverse link, while two radius rods run forward to the bulkhead behind the cockpit. This system as in use until the final race of the Championship season, at Watkins Glen, when two cars were modified to a parallel bottom link layout to reduce the bump-steering of the rear wheels. The 5-Speed gearbox is hung out the back, as on the Grand Prix cars, and in the early part of the season it was redesigned to make it easier to dismantle at circuits to change gear ratios. A tubular structure above the gearbox carries the regulation rear lights, stop lights and winker lights, and between the two clusters is a small oil cooler for the gearbox oil, air being fed to it from a duct in the top of the tail. From this assembly two air ducts feed cooling air to the differential housing. On the left of the gearbox is the 12-volt battery and on the right the regulation oil breather catch-tank.

In the cockpit the driver has a small leather bound wheel, with a Ferrari badge in the centre and looking through the wheel he sees three instruments. The centre one is a tachometer, clearly marked from 2 to 12, these figures representing engine r.p.m., when multiplied by 1,000. On the left is a gauge divided vertically, the left-half showing fuel pressure and the right-half showing oil pressure, and on the right of the tachometer is another gauge, with two needles which sweep round a temperature scale. These needles read oil temperature and water temperature. In both cases the oil needle is a red one, the fuel pressure and water temperature needles being white. Below the oil gauge is a red light to indicate low fuel level in the tank, and on the central backbone between the seats is a small lever that operates a fuel cock by means of a cable, there being enough petrol in reserve to complete a lap on most circuits; in front of it is a warning light to show the reserve cock is open. In the centre of the cockpit is an ammeter mounted above a switch panel which contains switches for the headlights, a switch for the Lucas electric pump for the fuel injection system, a conventional ignition key which is turned for starting the engine and a special switch which connects current to a tiny button on the right-hand spoke of the steering wheel which flashes the headlamps when depressed. On the right side of the cockpit is the short stubby gearlever controlling the 5-speed gearbox, the lever moving in a small gate, with first gear over to the left and back, reverse forward on the left, protected by a catch operated by a separate lever. Second gear is in the middle of the gate and forward, third gear is back, fourth is forward to the right and fifth gear is back to the right. The lever operates a control rod that runs back along the chassis frame to a pivoting link behind the driver’s seat that moves the motion in towards the centre of the car. Another control rod runs along above the engine and across to the centre of the car and back into the selector mechanism mounted on top of the gearbox. Anyone who has heard a 312P Ferrari accelerate up through the gears after a pit stop will know that the control system is perfect. The clutch, brake and accelerator pedals are mounted at their lower ends and the fluid reservoirs project forward of the front bulkhead in a fibre-glass box.

The bodywork is in two pieces, made in fibre-glass, the front one hinging about pivots by the front lower wishbone mounting. It includes the sides of the cockpit and the doors, which hinge upwards and incorporate ducts taking air to the water radiators. In the front of the full-width nose is a slot that allows air to pass through and out of an opening in front of the windscreen, this air flow providing a degree of down-thrust on the front end. The rear part of the body hinges about points on the crash-bar, just behind the cockpit, and is clamped at the rear on to the rear lamp mounting, being located by pegs, with over-centre mechanical clips and rubber tension clips. Three tail sections were developed for the car, a short stumpy one for slow circuits, an intermediate length tail and a long tail which was only used in testing at Le Mans. For most of the races the intermediate length tail section was used and this weighed 7 kilogrammes more than the short tail, but gave an increase of 6-8. k.p.h. in speed.

During the season all eight existing cars appeared at some time or another, either for racing or testing, and they were so identical in construction that none of the drivers could really tell one from another, never being sure whether they drove the same car twice or not. Although there were a number of crashes during the ten races in which the team took part, no car was written off, the damaged ones being repaired and put back into service. At the races there was a complete spare set of front and rear body sections, painted with the appropriate numbers on them ready for immediate use during a race if damage occurred, as for example on the Ickx/Regazzoni car at Spa when a burst tyre damaged the tail section. These spare body sections were carried in crates made from small diameter tubing that looked like a space-frame for a “Birdcage” Maserati. With as many as four cars running in a race the spares and wheels required were enormous, for each car had two or more sets of wheels available, with “dry” or “wet” tyres fitted. Front wheels are 13 in. diameter with 10 in. wide rims, and rear wheels are 15 in. diameter and 15 1/2 in. wide, using Firestone tyres. All-up weight varied from 655 to 670 kilogrammes.

This year the Ferrari team has been fortunate in not having any very serious opposition, for Matra refused to race against them and Ferrari withdrew from Le Mans, while the Lola-Cosworth team of Ecurie Bonnier could not hope to match the Ferrari team on pit work, even if the car was fast, and the Gulf-Mirage ream were still in the makings with their new car. For all the opposition they supplied the Alfa Romeo team might not have been there. Next year it is hoped that the Mirage with its new V12 Weslake-Ford engine and the Matra team will give Ferrari some strong opposition, unless the announced withdrawal takes place, but meanwhile he has swept the board by looking ahead and being ready, as he has done so often in the past. — D. S. J.