artomotive

Classic cars, defined by the human hand

Prototype Parade #230 | Model Cars December 1966 | Drawn & described by D. Windsor

Honda 3L V12 1966

T HE NEW HONDA V12 made its racing debut at the Italian G.P. on September 4th, and though numerous titbits were printed during its trials at Suzuka, it was only then the press could assess it properly.

However, nothing is ever as simple as one hopes and, while comment was profuse, it was in many ways contradictory. Three or four sets of measurements were published, while criticism ranged from "beautifully made, of enormous complexity" (Autosport) to "The workmanship seems surprisingly crude and heavy in comparison with Lotus and BRM detail work" (Motoring News). Ultimately, the plans were done to measurements published in Autocar on appearance of the prototype at the end of August and these have subsequently been confirmed as correct.

It is a complex car, as complicated as its exhaust system suggests, being conventional only in its monocoque construction and suspension layout. Honda's chassis designers went the whole hog on the new car and produced a full monocoque with two pontoons at the rear, similar to the BRM 2 litre cars and the Indy winning Lotus 38. Indeed the Honda resembles the Indy winner in many ways and this is not surprising as their chief test manager Sekiguchi said of Len Terry, "He is currently the world's greatest designer". The hipbath chassis, so popular under the 1½ litre formula, is at long last obsolete. The chassis unit was made by an aircraft company in duralumin with attention paid to ease of maintenance and with the suspension mounting points and stress areas in steel. The rear pontoons support the engine and also hold two of the 8 fuel tanks which altogether hold 70 gallons of 100 octane B.P.

Honda 1966 V12 cutaway drawing

The engine, which is now mounted longitudinally behind the driver, is a 90 degree V12 with the exhausts in the centre of the V and is an entirely new design. It has a capacity of 2,992 cc., with 4 valves per cylinder and a single 12 mm spark plug in a humped piston, not of truly hemispherical pattern. The bore and stroke are 78.0/52.2 while the claimed 400 bhp at 10,000 r.p.m. is probably a little optimistic. Power is taken from the the middle of the engine which subsequently looks like 2 V6s, the camshafts are also driven at their centres as are the timing gears. The output shaft runs back along the base of the V to the gearbox, fuel injection is by Honda's own port type method and the compression ratio is 1.5 to 1. The rev counter in true Honda tradition has no limit and goes up to 15,000 rpm, yet ironically Honda say they will not use transistorised ignition until they use high revs!

To transmit all the expected horses the Japanese firm have rejected the Howland gearbox previously used, and now make their own unit with 5 forward speeds, reverse, and full synchromesh as gear crashing is becoming prohibitively expensive with the new formula. An alternator is built onto the rear of the box, which has its own cooling system and radiator mounted on the near side with a scoop to collect air from beneath the car. Great attention has been paid to cooling and the engine has no cover, while the petrol itself is passed through a radiator before entering the fuel injection system. This radiator is mounted behind the roll-bar. The positioning of many of the smaller auxiliaries seems to be undecided and the fuel pump alongside the near side pontoon will probably not remain there long.

The half shafts are solid with Hooke joint universals at both ends, the necessary movement coming from the stub axles as on the Mexican G.P. winning car. Wheels are by Halibrand being 15 in. supporting Goodyear tyres considerably wider than those of the 300 b.h.p. Brabham. Suspension is conventional with a reversed wishbone, transverse top link and twin radius rods at the rear, unequal length wishbones at thu front operating inboard springs which are cooled by channeling air from the sides of the radiator (as on the Ferrari). The front hubs have the steering arms moulded into them, unlike western practice, and the roll bars are both adjustable without removal from the car. The stopping power is provided by Girling discs of the solid variety mounted inside the wheel hubs (only Ferrari have used the ventilated slotted discs available).

Body work is almost non-existent only; a detachable nose cone was fitted at Monza, and it is unlikely that any attempt will be made to hide all the internals until the position of the auxiliaries is finalised. In the nose there is an air outlet similar to the McLaren and Lola sports cars for creating a flow from the radiator over the car at speed, the Japanese mechanics would not say what the scoop or hump on top of the nose were for. At the rear the car is nicely set off by the twelve pipes running into the four tail exhausts without megaphones. The whole proved very heavy, scaling 740 kg at Monza. It is finished in white with a red stripe down each side and a red disc on the nose immediately in front of the cockpit. The numbers were black (18 at Monza) as was the leather lined cockpit and the 12 in. steering wheel. The gear shift stick is on the right, and the wheels are left metal colour, the exhausts being covered with special matt white heat-proof paint.

Drivers are Ginther and Bucknum with the possibility of a third next year; just who is the source of usual rumour!

Despite its crash at Monza the car showed surprising potential for its first race, and was on the point of taking the lead when the off side rear wheel locked, causing it to leave the road at high speed. It struck a tree side-on and it is a tribute to the new Honda's strength that Ginther escaped only with a fractured shoulder. By the time this is in print another may well have appeared in time for the Mexican G.P.

Dimensions: Wheelbase 8 ft. 2½ in.; Length 12 ft. 11 in. Rear 4 ft. 11 in. Body width 2 ft. 5 in. (to roll bar). Tyres ft. 7/15; 10.50/15.

model-cars

Honda 3L V12 1966

Honda V12 1966 technical drawings
model-cars

Honda RA302

Honda RA302 technical drawings

Prototype Parade #287 | Model Cars November 1968 | Drawn & described by Roger Taylor

Honda RA302

A T the beginning of July, Honda announced their new all Japanese designed air cooled V 8 Grand Prix car. Its appearance, nearly two months before it was expected was a great surprise even to the John Surtees team, who did not expect to see the car until the Italian G.P.

The car was a completely new design from Honda, who seem to have abandoned the V 12 engine, because of its weight and its inability to obtain more than 400 b.h.p., the car has become outclassed by the main Fl opposition. The Honda RA 302, as the new car has been called, is powered by a 120 V 8 air-cooled engine with a cubic capacity of 2987 cc. with twin overhead camshafts operating 4 valves per cylinder, all the engine castings are covered in cooling fins.

The inlet ports are on top of the engine and the exhaust underneath allowing four exhaust pipes to curl up either side and over the rear suspension, similar to the V 12. The low pressure fuel injection is designed by Honda. The engine was claimed to produce 430 b.h.p. at 10,500 r.p.m. but only 380 b.h.p. was achieved when the car was run. The engine is bolted to the rear bulkhead behind the cockpit and a separate monocoque section is continued over the engine in the centre of the Vee to support a steel cross member which carries the rear suspension mountings and which is also attached to the gearbox. The gearbox is a Honda 6 speed unit, 5 forward and one reverse.

The chassis is a usual monocoque layout, the body design being the result of wind tunnel testing which proved necessary to locate the best position for the various air scoops as the engine is cooled entirely by air and high oil circulation. The ducts either side of the cockpit carry air to the Vee of the engine, while the ducts on the side of the engine feed air over the cylinder heads. To the left of the roll-bar is another scoop which feeds air to the crankcase to be mixed with the oil mist. The air, after going through a de-aerator, is expelled out of the rear-ward facing duct on top of the engine.

The exposed pipes on the right hand side of the body carry oil to and from the front mounted oil cooler, a large oil tank is situated on the right hand side behind the cockpit. Despite its large engine, the car, with its low nose section, forward cockpit position, looks very short and squat.

The coil spring damper units on the front suspension are mounted inboard, operated by upper bell crank arms and single lower link with forward facing radius arms.

Steering is by rack and pinion. At the rear, the upper radius arms run behind the exhaust pipes to the rear wheel upright, single upper link, lower radius arms, fabricated reversed lower wishbones and anti-roll bar are also employed.

The body is painted ivory overall with broad crimson horizontal stripes along either side and around the nose section. A crimson disc is painted on the body just ahead of the cockpit.

The car was briefly tested by John Surtees at Silverstone and inadvisably entered for the French G.P. On the third lap of the race in very wet condition the car crashed, burst into flames and was totally destroyed, this terrible accident claiming the life of Jo Schlesser.

It seems unlikely, at the present time that another RA 302 will appear in the same form as the one drawn. A second 301 V12 has been completed and no doubt John Surtees will complete the '68 season with these cars.

Dimensions: Wheelbase 92 ins. Track, front 59 ins.; rear 57 ins.

model-cars

Howmet TX

Howmet TX technical drawings

Prototype Parade #282 | Model Cars September 1968 | Drawn & described by Frank Clark

Howmet TX

F IRST the Rover B.R.M. then the S.T.P. Indy car, and now the Howmet, is this the beginning of the end for the piston engine in racing? Well we don't know but these cars have certainly added interest to Motor Racing.

The Howmet TX (for Turbine Experimental) was built for the Howmet Corporation of New York, a manufacturing firm of jet engine components and space age metals, by Bob McKee of Palatine, Ill., U.S.A., well known Sports car constructor, from designs by Ray Heppenstall.

The chassis is of tubular space frame construction with modern Formula One type suspension layout and the body is of aluminium — not fibre glass for a metal firm!

The engine is one of seven turbines built for a U.S. Government helicopter contract that the Continental Aviation and Engineering Corp., did not finish; Howmet managed to buy two turbines and the U.S. Air Force have the other five. The engine drives the car through a final drive/differential unit under the turbine, this is part of the reason for the high back of the car. The fuel used is JP5 a mixture of paraffin and petrol, stored in a 32 gallon (Group 6 limit) tank behind the driving compartment. At the present the car cannot go much over one hour on a tank full of fuel, this obviously is a restriction on the car's performance.

The turbine revs. at 57,000 r.p.m. which is reduced to 6,700 r.p.m. at the driveshafts, the car has one single forward speed and an electrically driven reverse. Power is approximately 330 b.h.p. As the turbine does not contribute to the braking of the car as in a piston engined vehicle, disc brakes are fitted of 11½ inch diameter, but nevertheless there had to be a way to switch off some of the power, also to get the power back quickly. This was accomplished by what is termed a 'waste gate... The idea is that when the driver wishes to 'back off' for a corner he opens the gate and the surplus unwanted power byasses the drive of the car, this can be done to a lesser or greater degree controlled by the throttle pedal. With this type of throttle/waste gate control combined the driver can get power back on quickly — in the past a drawback with turbine driven cars was this power lag.

Two cars have been constructed, one with a 2¼ inch shorter wheelbase than the car depicted in the plan as raced in the B.O.A.C. 500 at Brands Hatch and Oulton Park. The cars run under Group 6 Prototypes in the 3 litre class, and weigh only 77 lbs. over the 3 litre limit.

The first appearance of the car was at Daytona for the 24 hour race on 3rd/4th February, 1968, recording 7th fastest time. Drivers were Dick Thompson and Ed Lowther, both Howmets were entered but one had bearing trouble in practice and was not raced. The car, Number 76, ran well until the valve in the waste gate jammed and as the car was on full power at the time the driver was unable to control the ensuing slide and the Howmet hit the retaining wall and had to retire.

As depicted in the plan the car is as raced at its next race the B.O.A.C. 500 at Brands Hatch on 7th April, 1968, the racing number was 35 and the drivers Thompson and Dibley. The car ran well in practice and recorded a surprising 6th fastest for such a short winding circuit and against strong opposition from Porsche, Ford and Lola. On the first lap the Howmet was 5th ahead of the new Ford V8 prototype, but unfortunately the waste gate trouble recurred and on lap seven Thompson was unable to stop with the power again jammed full on, and the Howmet ended its race in the bank at Druids, at which the waste gate opened and a massive burst of power through the exhaust sent the spectators scurrying away. The smaller of the three funnel like projections at the rear of the car is the waste gate exhaust and the others the normal exhausts from the turbine, all pointed skywards so as not to cook the opposition behind the Howmet.

Always beautifully turned out, the car at Brands Hatch was in the company colours of white with the front bonnet deep blue edged with gold, all the engine cover and the cockpit roof and window edgings are polished metal with cast metal wheels. The wing mirrors are chromed with the lipping in the front wheel arches also polished metal. Numbers are black on white discs and the discs edged with gold or black.

The words Turbine Experimental are on the sides, white on a blue background, the background is edged with gold. `Howmet' is ahead of this in blue. Various trade stickers are attached to the car, the C.A.E. one being the turbine make, also Gulf, B.O.A.C., Goodyear and a black P on a white rectangle for Prototype.

In some of the accompanying photos caps have been fitted over the turbine exhausts and the filler caps and engine air intake have been taped over, this was done before the race and all tape and intake capping was removed at the start. Some of the photos were taken at Brands and others at Oulton Park. The lipping was put on the front wheel arches after practice at Brands and at Oulton lipping was added at the rear wheel arches. Owing to the shunt at Brands the car had a hastily painted front with the lipping at the front and all but the hatch at the front painted white. The perspex head lamp covers were replaced with white metal ones as well. At Daytona all the rear opening was covered by wire mesh, two lamps were fitted at the extreme front but these were covered by metal plates at Brands and Oulton. The bar at the extreme rear is for jacking up the car, N.A.C.A. scoops are fitted for brake cooling.

The steering is left hand (13 inch wheel) and the instruments are contained in a large console dash on the right, angled towards the driver, all the interior is black. The rear view for the driver is practically none existant except for the mirrors.

Wheelbase 7 ft. 9½ in. and 7 ft. 7¼ in. Front Track 4 ft. 10½ in. Rear Track 4 ft. 8½ in. Height 3 ft. 10½ in. Length 12ft. 10 in. Width 5 ft. 11½ in. Different size tyres have been used, usually: Front 10.50 x 15 Low Profile Rear 12.50 x 15 Low Profile