THE paddock at Monza was a delight for anyone interested in Grand Prix cars and engines, for the greatest collection of 3-litre cars was gathered together for the Italian Grand Prix. The only pity was that so many people who got into the paddock seemed more interested in collecting autographs and talking about the weather than the wonderful array of Grand Prix machinery.
Centre of interest was the 3-litre Honda V12-cylinder car making its first public appearance, being completely new from stem to stern. By any standards it is a big and heavy car, but not so big if it was viewed as having 500 b,h.p., which it hasn’t at the moment, but might well have in two years’ time. The chassis is an orthodox “monocoque,” with pontoons running to the rear crossmember from the cockpit, and the suspension both front and rear follows what is now the orthodox layout, lower wishbone and upper rocker-arm operating a coil-spring/damper unit on each side at the front, and lower apex-pivoted wishbone, transverse link and double radius on each side at the rear, with coil-spring/damper units. The stressed-skin chassis contains nine separate fuel tanks, including one under the driver’s seat.
The engine is unusual in being a 90-degree V12-cylinder layout, unlike the more usual 60-degree V12 configuration, and like the Honda F2 engines everything is running on ball or roller hearings. There are four overhead camshafts, driven from a train of gears between the front six cylinders and the rear six and the power shaft is taken from this gear train, above the camshaft centre-line, the flywheel and clutch assembly being at the rear of the engine. The engine is mounted longitudinally, unlike last year’s Honda G.P. car where it was transverse. Each combustion chamber has four valves, two inlet and two exhaust, the inlet ports being down between the camshafts on each bank, and the exhaust ports being in the centre of the Vee, as on the Indianapolis Ford engine and V8 B.R.M. engines of last year. Long inlet tracts stick out on each side of the engine and a long and complicated exhaust system is used, ending in four horizontal tailpipes above the gearbox. The cylinder dimensions are 78 x 52.2 mm. bore and stroke, giving 2,991.648 c.c. capacity and with one central 12 mm. sparking plug and a 10.5 to 1 compression ratio, 400 b.h.p. at 10,000 r.p.m. is the aim. In this first form 370 b.h.p. was quoted freely and 10,000 r.p.m. was not expected to be reached in fifth gear.
It is a big car, having a 98.8-in. wheelbase, 56 1/4-in. front track and 55-in, rear track and there did not appear to have been any attempt to save weight, lots of parts, such as the drive shafts, being very massive. As on the 1965 car the drive shafts are solid and rear suspension movement is taken up by stub axles that slide in and out of the hub carriers on splines. The wheels are cast magnesium, made by Halibrand, and Goodyear tyres are used. The 5-speed and reverse gearbox looks very big and strong, and has its own oil circulation with an oil cooler mounted on the left side, complete with a scoop for collecting air from under the car. Driven off the end of the gearbox is an alternator, it being built into the gearbox end cover. Behind the driver’s head is a cooler unit for the petrol and Honda’s own port fuel injection is used, the injection metering unit being driven off the right hand exhaust camshaft and there was an air-cooling duct blowing on to this unit. Painted white, with a red stripe along each side and the name HONDA in large letters on each side of the cockpit, it impressed by its size and purposefulness, looking as though it had been designed for the end of the 3-litre Formula rather than the beginning. It weighed 740 kilogrammes empty, which is almost half as much again as the Formula limit of 500 kilogrammes. There was no attempt to provide any body panels over the rear of the car.
Equalling the Honda for interest was the latest Eagle from Dan Gurney’s All American Racers Inc., although the chassis design has already been seen and has proved itself, using a 2.7-litre 4-cylinder Climax engine. The new car was chassis 102 and was fitted with the first of the 12-cylinder 3-litre engines designed by Aubrey Woods at Harry Weslake’s engine development works at Rye in Sussex. The engine is named the Gurney-Weslake and is the most compact 12-cylinder engine ever seen. The cylinder layout is two banks of six cylinders at an included angle of 60 degrees with the inlet ports in the centre of the vee and the exhaust ports on each side. Each bank has two overhead cam-shafts driven by a train of gears at the front and each pair of camshafts are contained in a single-piece cast cam cover, with central sparking plug to each cylinder. There are two inlet and two exhaust valves to each cylinder, the valves and valve gear being light and small to assist in the compactness of the engine. The bore and stroke are 72.8 x 60.3 mm., giving 2,997 c.c. and the engine is intended to give maximum power at 10,000 r.p.m., with a subsequent development to 12,000 r.p.m. Lucas fuel injection is used, the metering unit being driven by toothed belt from the rear of the right hand inlet camshaft, while the companion exhaust camshaft drives the rotor pick-up for the Lucas transistor ignition. Relatively short inlet trumpets are used and the exhaust pipes are grouped in threes, ending in four megaphones which emit a very hard note. So compact is the Weslake engine that the body panelling, when fitted, will cover all the mechanism completely, presenting a very sniooth outline. As on chassis 101 a 5-speed Hewland gearbox is used and apart from having straight tube lower-wishbones at the front, the chassis and suspension follows the earlier car.
The first day that the new engine ran on the test-bed it gave over 300 b.h.p. at only 8,500 r.p.m. and subsequent testing convinced A.A.R. that they had enough power to be competitive so the engine was installed in the new chassis and rushed to Monza. Unfortunately there was no time to run the car and it was plagued by fuel feed problems due to the hurried installation. When fuel did arrive at the metering unit it ran very smoothly and cleanly on all 12 cylinders and sounded very promising.
The Ferrari designers have been experimenting with new cylinder heads for their V12 engine for some time, trying a four-valve and a three-valve layout, and the three-valve layout, of two inlet and one exhaust, was tried out on a V6 Dino engine first of all. At Monza three of the new V12 engines appeared, the two inlet valves being situated between the camshafts on each bank of cylinders, instead of in the vee of the engine. A single inlet trumpet feeds each pair of valves by an inverted Y-manifold and the Lucas injector nozzle squirts upwards at the manifold fork. The exhaust ports are on each side of the engine and a much smoother and tidier manifolding is used, ending in four tailpipes. Two 10 mm. sparking plugs per cylinder are still used and are fired by coil ignition, with four coils on the right hand side of the gearbox and a 12-pole distributor on the rear of each exhaust camshaft. The left hand inlet camshaft drives an alternator by toothed belt, and the right hand inlet camshaft drives the Lucas fuel injection metering unit. A very vague 380 b.h.p. at 10,000 r.p.m. is claimed, but 360 b.h.p. is probably more near the mark. Whatever the power output, it was enough to propel the Ferraris faster than anything else.
While the Maranello factory had been working on new cylinder heads so had the Maserati factory in Modena and the Coopers had engines with altered inlet tracts and rearranged accessory drives in an attempt to improve the power output and reduce the bulk of the engine. On the old engines the inlet pipes stick out each side, rising straight out of each cylinder head of the V12 unit. The new porting had the inlet tracts inclinded in to the centre of the engine and instead of the two distributors for the dual ignition being side-by-side on top of the engine they were rearranged to be in-line down the centre of the engine, driven back-to-back. The barrel throttle system was retained but there was one engine with the Lucas injectors in the inlet bell-mouths and another with the injectors down near the valves, below the throttles. A third type of engine appeared during practice with the earlier port layout but using Magneti-Marelli coil-ignition in place of the Lucas transistor ignition.
At Bourne the B.R.M. engineers had done a vast amount of development work on their H16-cylinder cars, and the results were to be seen and heard in the paddock at Monza. When the H16 layout was first mooted I suggested that the sound of 16 cylinders would be glorious. Numerous readers wrote in to say that I was quite wrong as the H16 would be firing two cylinders at a time, and would sound like two V8 cylinder units. This was absolutely correct and the first H16 B.R.M. engines were of the double-eight firing order layout. Various high frequency vibration problems arose and though these were overcome by means of balance weights on the crankshafts and damper discs on the camshafts, the problem was not solved satisfactorily. At Monza one B.R.M. engine had entirely new internals with a firing order of a straight-forward 16-cylinder Unit. The other big problem that B.R.M. have had to solve has been a gearbox one, brought about by having the clutch and flywheel assembly at the rear of the gearbox with the clutch body on the gearbox shaft and not on the engine shaft. When the clutch was freed the inertia of the clutch body caused it to speed up instead of slowing down, so that the gear engagement dogs in the box would suffer and become chipped and not stay engaged. All the gears are in constant mesh and sliding double dog-ended sleeves lock the pairs of gears to the mainshaft. A complete redesign of the clutch layout has reversed the situation so that the clutch body now slows down with the engine during a gearchange.
It was thought that the cable-operated gearchange linkage was causing this gearchange problem, and it was replaced by a rod-operated linkage, but this proved not to be the cause of the trouble. On the Lotus 43, which uses and H16 B.R.M. engine and gearbox layout, the gearchange is still by push-pull cables and it works satisfactorily in spite of turning through some sharp corners as it runs front the left side of the gearbox to the right side of the cockpit. The Lotus 43 was also fitted with the new clutch layout and pivoted fork operating mechanism in place of the original central plunger at the rear of the clutch.
There was certainly a lot to see and to study in the Monza paddock, and elsewhere in this issue many of the new features are depicted photographically.—D. S. J.