Although Jack Brabham was first off the mark with a 1966 G.P. car with 3-litre engine, and he raced it in South Africa on January 1st, it was not until the Siracusa G.P. on May 1st that we were able to see the first of the 1966 cars in action against each other on a European circuit. The 3-litre Ferrari, the 3-litre Cooper-Maserati and the 3-litre Repco-Brabham all appeared, there actually being two Cooper-Maseratis.
The Ferrari was shown as a static exhibit at the end of last year and fundamentally remains the same, though there have been numerous detail changes in the light of much track testing at Modena and Monza. The main body/chassis structure is of riveted aluminium sheet, wrapped round steel tubes, the sides of the cockpit forming boxes to contain the rubber fuel tanks. The riveted structure extends rearwards along each side of the engine bay formed around tubular longerons, these tubes having engine mountings welded into them, and they run rearwards to a bulkhead on which the rear suspension is hung. The suspension of all four wheels follows the principles of the smaller 1965 Grand Prix cars, with i.f.s. by top rocker-arms and wide-base bottom wishbones, the rocker arms compressing a coil-spring/damper unit mounted within the body/chassis shell by the front bulkhead. The i.r.s. layout is conventional, with lower wishbones, pivoted at their apex, a single upper transverse arm each side and double radius arms on each side. The upper radius arms can be attached in either of two positions, depending on the required geometry, and during tests at Monza they were fixed from pivots at hub level to chassis points about 4 in. inboard on the shell. The alternative fixing, using the same length rods, is from the top of the hub carriers to chassis brackets on the outside of the shell. At Siracusa the car was tried first of all with the lower mounting and then changed for the higher one, and it was raced in that condition. Coil spring/damper units are mounted between the forward end of the bottom wishbone base and the top of the rear bulkhead, and quite a small anti-roll bar is fitted, with not very large adjustment. The 12-cylinder engine is on the well-tried Ferrari lines of a 60-degree vee, with four overhead camshafts, and has a 4-point mounting in the engine bay behind the cockpit. Lucas fuel injection is used, with sliding-plate throttles, long trumpets, and the injectors squirting down on to the throttle plates. Ferrari are conducting experiments with direct cylinder-injection at high pressure for this engine. Two sparking plugs per cylinder are used and these are fired by four coils, mounted two on each side of the gearbox, and two distributors ; the .12-point distributors being driven from the rear of the exhaust camshafts, with aluminium heat shields round them. Exhaust pipes are in groups of three, with two tail-pipes from each bank of cylinders, the four tail-pipes curving over the back of the engine to finish just above the .gearbox. The oil tank for the dry-sump lubrication is in the nose of the car, behind the radiator, the nose cowling having slots on top and underneath to allow the escape of hot air. Alternator and rectifier are mounted behind the driver’s head and the Lucas 100 lb./sq. in. pressure pump is mounted on the rear of the gearbox. The latter is a 5-speed and reverse unit with integral crown-wheel and pinion, and the clutch is in the orthodox position on the rear of the crankshaft and not out behind the gearbox, as on last year’s Le Mans cars which used this type of 4-camshaft engine. The 3-litre 12-cylinder engine is rated to turn at 10,000 r.p.m. and should give 360 b.h.p., but at Siracusa it was pulling 9,800 r.p.m.
The front disc brakes are mounted at the wheel hubs, sunk inside the 14-in. bolt-on wheels and are radially perforated, with scoops directing air to the central annulus. At the rear the disc brakes are mounted inboard, on each side of the gearbox/final drive unit and universally jointed sliding spline-and-ball shafts transmit the drive to the wheels. Although the weight is claimed to be 548 kilogrammes, the car turned the scales at Siracusa at 604 kilogrammes (1,328 lb.).
The 1966 Cooper-Maserati was first shown to the public at the Racing Car Show at the beginning of the year, and at the end of last year a prototype car had been out an test. This was a 1965 tubular chassis car designed to take the 16-cylinder Coventry-Climax engine, into which Coopers had contrived to fit a V12 Maserati sports-car engine. This “special” taught them a great deal, and meanwhile Derek White and his design assistants were at work on the new monocoque chassis. Apart from the factory team cars, three privately owned ones were ordered and the R.R.C. Walker team took delivery of theirs for Siracusa, as did the French driver Guy Ligier, The chassis is a riveted aluminium structure with fabricated steel bulkheads and steel sheet for the sides of the engine bay. The sides of the chassis form boxes into which flexible fuel tanks are inserted, these filling the whole length of the structure. Front suspension is independent by an upper transverse rocking arm, fabricated from sheet steel, the inner end compressing a coil-spring/damper unit, and wide-base lower wishbones are used. At the rear are lower wishbones, boxed in at their apex where they pivot on the chassis, transverse single upper arms and double radius rods on each side. Coil-spring/damper units. are used and a heavy anti-roll bar, with a large adjustment. Brakes are hub-mounted back and front, the front ones being inboard of the hub carriers in order to expose them to the cooling breeze and to permit the discs to be of a larger diameter than the inside-of the wheels.
The 12-cylinder Maserati engine is mounted behind the driver and is coupled to a 5-speed German ZF gearbox and final-drive unit, with sliding joint drive shafts taking the power to the-wheels. The 4-camshaft engine has the inlet ports running down between the camshafts on each cylinder head, and Lucas fuel injection is used. At first motorcycle-type sliding throttles were used for each cylinder, but before the cars were raced these were changed for barrel-type throttles running on ball-races and joined together by ball-joints and rods, there being individual ram pipes and throttles for each cylinder. The exhaust pipes are grouped in threes and end in short tail-pipes high over the rear suspension, two on each side. With two sparking plugs per cylinder the 24 plugs are fired by Lucas transistor ignition, there being four transistor boxes mounted on the crash-bar behind the driver’s head. Sparks are distributed by two 12-pole distributors mounted in the vee of the engine, driven from the camshaft gear train on the front of the engine, and the left-hand one has an alternator incorporated in it. Oil for the dry-sump system is carried in a tank in the nose of the car and there is an oil filter mounted above the gearbox. Under the gearbox, and insulated from it, is a collector tank fed from the main fuel tanks, this feeding the pressure pumps. Provision is made for a rudimentary engine cover, but there is so much machinery behind the driver that the cover looks superfluous. At the moment the engine turns easily to 9,500 r.p.m. and future development should see it at well over 10,000 r.p.m.
The Rob Walker car is painted dark blue with a white nose band and the Ligier car is painted bright French blue, both these cars being privately maintained but with keen works interest behind them, from both Cooper and Maserati. Both weighed over 600 kg.
The Brabham connection with the Repco engineering firm has already been described in Motor Sport and he had his first 1966 Grand Prix car with 3-litre V8 Repco engine ready for the South African G.P. He got further experience in the Australian races with a 2 1/2-litre version, and made his first European appearance with the car at Siracusa. The 1966 Brabham chassis follows the basic principles of the 1965 Grand Prix cars, having a tubular space frame, the frame being constructed from a combination of round section, oval section and square section tubing, the upper tubes around the cockpit being of oval tubing. Fuel tanks are of aluminium and are slung pannier-wise on each side of the cockpit, and the oil tank is behind the radiator. Suspension is by double wishbones at the front with interposed coil-spring/damper units out in the air stream, and rear suspension is the orthodox Grand Prix layout of lower wishbone, upper transverse arm, double radius rods and inclined coil-spring/damper unit.
The Repco engine is mounted behind the driver and is a 90-degree V8-cylinder with single-overhead camshaft on each bank of cylinders operating in-line valves. Lucas fuel-injection is used, squirting into the downdraught inlet pipes, and the four exhaust pipes on each side join in their own cluster end and single tail-pipe with slight megaphone. At the moment the eight 14-mm. sparking plugs are fired by a Lucas coil, and a Bosch distributor driven from the camshaft drive and mounted in the vee of the engine, while on the left-hand side, under the exhaust pipes, is a Bosch dynamo. The engine is coupled to a 5-speed Hewland gearbox and final-drive unit. Disc brakes are used and are-fitted outboard both back and front. Whereas the Cooper-Maserati seems over-full of machinery in the back, the Brabhain-Repco seems sparse and lacking in machinery, due to the simple single o.h.c. valve layout.
These three cars were the first new 3-litre Grand Prix cars to appear under the new Formula and can only be considered to be the forerunners of what we can expect in Grand Prix racing during the next few years. Already Ferrari is working on a new engine, which should appear by September, Maserati have plans on the drawing-board that may come to fruition in conjunction with Cooper, and will involve more than twelve cylinders, and Repco really look upon their engine as a sports-car unit that Brabham is using as a stop-gap. This new Formula for Grand Prix racing seems to have got away to a flying start as far as mechanical interest is concerned, but I feel we must show a little patience before we shall see really close-fought battles between the 3-litre cars.—D.S.J.