GRAND PRIX '70
HALF - TIME
Reviews the technical aspect of the formula 1 scene
It seems possible that the 1970 season will go down in formula 1 history as the time when the 12-cylinder engine at last asserted the superiority which it has held in theory, but not in practice, since the beginning of the 3-litre formula.
It is axiomatic that the car with the best engine and the best tyres will win formula 1 races. Some chassis are better than others, but the not-so-good ones are still winners if they have the best power-unit propelling them and the best tyres to give them maximum adhesion on the particular circuit they are racing on.
It was evident there that Pescarolo, who is a' brave but not over-experienced formula 1 driver, could hold drivers of the calibre of Jack Brabham by reason of the superior power of his car. But the Ford-Cosworth still wins.
Now that Cosworth crankshaft trouble is solved and the camshaft gear drive breakages, due to torsional vibrations, have been cured by the addition of a carefully calculated amount of rubber, there should be fewer retirements using this vee-8 engine. Logistics of course come into it. The least well-equipped teams have two engines per car and the wealthy ones three or four; in all there are about 70 Ford-Cosworth engines in being. With the short time between races at the beginning of the season coinciding with a high rate of mechanical failure, the works have been somewhat inundated at times and it has become necessary for engines to be taken out of cars immediately after races and flown back to England to get to the front of the queue.
Recent troubles with the DFV have been in the piston area. With the very high cost of machining cylinder blocks, steel cylinder liners are used to contain the damage if a piston breaks up-possibly due to a valve touching or if a connecting rod should deviate. A persistent scuffing problem, causing pistons to break up, has cost a number of engines of which three have been Ken Tyrrell's. Failure is thought to be due to overheating, the particular piston metal used having a 30 per cent reduction in strength in the 200-250 deg. C. band. The latest thought is that an anti-scuffing lacquer applied to the top land of the pistons is acting as a heat barrier and diverting heat to the gudgeon pin area. When this trouble does occur there is a considerable dropping off of power due to friction or blowby.
Undoubtedly all the constructors of 12 cylinder engines have had similar problems. Matra had acute ring and piston trouble at Le Mans with engines similar to those raced in formula 1. Moreover they failed at about grand prix distance. There was a connecting rod failure at Jarama although Pescarolo's engine lasted the distance at Monaco and he came a very worthy third on the same lap as the winner, and they have not since suffered an engine failure in a Grand Prix.
Ferrari, too had piston trouble early in the season with their' horizontally opposed 12-cylinder-strictly speaking it is a 180 deg. vee-12 rather than a "boxer" motor-but this was overcome after Monaco and the latest problem seems to be one of keeping the valve seat inserts in place. While the piston problem existed it was impossible to run for more than 15 minutes at full power. At the time of writing maximum power is realized at 11,600 rpm, 455-466 bhp DIN being the figure quoted with maximum torque 253 ft lb. at 9,200 rpm. This latest engine has are extremely narrow valve angle, less than 10 deg, and long straight inlet tracts. In common with all other formula 1 engines there are four valves per cylinder, with a single sparking 'plug in the middle of the head.
At the British Grand Prix on Saturday it will be interesting to see whether a fuel distribution problem above 10,500 rpm has been permanently cured. Incidentally, one of the handicaps of the 12 cylinder engine is the amount of fuel which has to be carried. Most of the 12s have 45 gallon tanks while the Cosworth engined cars can just manage with 40 gallons, a saving of 351b in starting line weight. The vee-8 engines give their best power when set a little weak (not weak enough to burn the pistons) and Rindt was able to win at Clermont for a consumption of 29.5 gallons of fuel.
The news that Dunlop are to pull out of formula 1 racing for financial reasons underlines the great expense incurred by sponsors, especially if they have to produce components as well as providing financial backing. Possibly the disruption of routine experimental work, because of the pace of development of racing tyres, may be another reason for withdrawal. It is to the credit of the people from the. Fort that they were able to offer Ken Tyrrell and BRM a choice of 13in. or 15in. rear wheel equipment. Also they designed and. built ultra-low-profile 1 5in. tyres of. the same frontal area as a 13in. tyre. This did not suit Stewart's March initially because of the camber change with early rear suspensions; for this reason a special Dunlop tyre with a rounded section tread was specially constructed for the Monaco Grand' Prix. Shod with 350 compound, it was 31b lighter than the then normal tyre.
At the time of writing Firestone lead in race tyre design and in the efficacy of their compounds. Their only drawback seems to be a liability to punctures one of which cost Ickx second place in the Dutch Grand Prix. In that race the tendency of the Goodyear G20's compound to pick up oil and sand put them at a disadvantage and caused a worrying accident to Jack Brabham, when, in practice, he was trying out Goodyear's version of the ultra-low profile 15in. tyre. However at Clermont-Ferrand Goodyear came back with a G24 soft compound tyre which allowed Beltoise to make second fastest practice time.
Last year it was established that the combination of wide tread tyres and the regulation airfoil was as effective as four-wheel-drive in getting a car quickly round a circuit, and much more to drivers liking. This year, at Spa a series of experiments, by Rob Walker and Ferrari with and without wings and nose foils, and Matras with narrow section tyres, proved that the combination of wide tyres and airfoil is still best on even a fast circuit like Spa. However the cars were faster in a straight line without foils. Graham Hill was said to have been clocked at 182 mph by Matra. In that race Matra used narrow front tyres, bearing out the dictum that it is only the front wheel size that matters aerodynamically, the air being thoroughly churned up by the time it gets to the back wheels.
It is, proving that the regulation wing and nose foils are extremely effective. The handling of Amon's March at Spa was unpredictable until the aerodynamic devices had been set up while Lotus found, among the other snags with the 72, that the rear airfoil was deflecting downwards 1.25 in. This was bending the whole rear structure and causing a backwards pitching moment affecting the handling until the rear mounting was stiffened.
The rise and fall, literally, of the Lotus anti-nose dive and anti-squat front and rear suspensions looks very much like the triumph of experience over hope. Maurice Philippe had hoped to eliminate some of the shortcomings of the geometry of this type of suspension which came up when Lotus themselves, and John Cooper, tried it some years ago. He did not succeed, although the whole of the early disappointments with the 72 should not be laid at the door of the suspension. In the revised car the whole structure has been stiffened with diaphragms in the tank bays-the car now has two tanks per side-and by stiffening up the space frame structure supporting the front suspension. It was convenient to do this while the structure was being revised to suit the so-called "parallel" geometry. The anti-dive and anti-squat is still being tried with the new structure but the parallel geometry is winning races.
A car as revolutionary as the 72 is bound to need some sorting out. Team Lotus have done this in an incredibly short time thanks not only to the perception of Colin Chapman and Maurice Philippe but also to the unremitting and faithful toil of the mechanics who have worked from 8 a.m. to 10 p.m. for 10 weeks with only four days off.
One thing which has worked very well in the 72 and is bound to be copied is the radiator position. Initially the Lotus radiators were not getting their fair share of air and there was a little overheating, but this was quickly rectified by altering the shape of the duct. The advantages of this arrangement in giving short water pipe runs and a clean nose shape are considerable.
With so little weight in the nose of the car it was imperative to retain the inboard brake set-up in order to have an acceptable ratio of sprung to unsprung weight. Problems have been mainly in practice, or whenever the car stopped during a race. The heat from the discs, in the absence of a hub and wheel as a heat sink, would melt the lubricant in the disc bearing and constant velocity joint; radiated heat also burnt the nose cowlings. Colin Chapman has overcome this by providing a pair of electric fans, mounted on a glassfibre cowl, which are pion ked over the brake ventilators when the car stops in the pits. Incidentally it will be noticed that Lotus have opted for solid discs after experimenting with ventilated discs. The reason is that when' the car is in motion the brake cooling is so good that ventilated discs cool off too fast between applications whereas the solid discs retain some heat and are therefore more stable.
Another area of overheating on the 72 was with the rear dampers which in their original position were close up to the exhaust pipe resulting ih the fluid boiling. Rindt won at Zandvoort without rear da mping for this reason. For Clermont they were relocated in the conventional position between the rear suspension cross member and the wheel carrier, where they not only run cooler but have a greater mechanical advantage.
Compared with the drama at Hethel the other teams seem to have had a relatively quiet time. If one excepts, BRM who have worked overtime in getting real power out of their 12 cylinder. It is rumoured that a small contingent from the Midlands were partly responsible for the change of fortunes. Certainly the engine is giving at least 10 bhp more than the Cosworth but is still saddled with a connecting rod problem. One reason for the improvement was the discovery that the spark plug combustion chamber combination has a very high voltage requirement which could only be met by using Marelli ignition, which gives a higher voltage at high revs than that obtainable from the Lucas OPUS system.
Apart from the front wheel bearing problems at Jarama, which was a supplier problem rather than one of design Tony Southgate's new design has been reliable and effective and its simplicity must have allowed the faithful band from Bourne an opportunity to concentrate on the power unit.
The BRM being a proper racing car with all the major components designed at Bourne and mostly made there, it does not benefit from the cumulative experience which users of kit parts enjoy. They have had to sort out their own gearbox problems, for example, mainly with gears jumping out of mesh or sticking in, I suspect due to splines cork-screwing under load.
March, a firm which did not exist in 1969, became one of the most significant in 1970 by reason of the illustrious selection of drivers, including the World Champio, who chose to drive their cars.
Designed by Robin Herd the car was intentionally non-revolutionary, being built on well established principles in an effort to avoid as many teething troubles as possible. For this reason its progress has been one of adjustments of the original design and the addition of lightness. The original monocoque was built from 18 swg alloy and is still used by all the 701 entries except Stewart's. His one, raced at Zandvoort and Clermont, was a special lightweight car built from 20 swg material; the works have a similar car which so far has been used only for testing. Quite early on the rear brakes were moved inboard to allow 13in. wheels to be used and the rear wing and nose foils have been modified in the light of experience.
One problem for March has been that their car is run on Dunlop, Firestone and Goodyear tyres, all of which have different characteristics. McLaren will inevitably fee the loss of Bruce, but they --will continue to race their M 14s powered by Ford-Cosworth and Alfa Romeo engines. These two power units are now, interchangeable so that the Alfa engine can be installed in the M 14 monocoque-it was originally in the heavier M7-when the type designation becomes M 14D. The main difference between the Alfa and Ford engines is the narrow power band of the former which inhibits performance when matched with a five speed gearbox.
The Brabham is another car which has so far remained very little changed although a new car is under construction with inboard disc brakes. It is meant to be ready for Brands Hatch. Since the first BT33 prototype was built it has been modified to take the full 40 gallon fuel load of the second. car. Originally designed to have wash-sealed tanks it was modified to bag tanks before it raced, with a loss of 5 gallons in tank capacity. Changes since that time there have been to the wheel uprights to accommodate 13in. rear wheels. The change to inboard rear brakes will allow bigger discs to be used with the small wheel size. Ron Tauranac evolved the shape of the car by a combination of theoretical and practical aerodynamics and claims that the regulation slotted airfoil gives a downthrust of 400lb at 180 mph.
Frank Williams will have a new De Tomaso to replace the one so tragically lost at Zandvoort but so far the driver has not been announced. The team have a spare, older car no doubt the new one will be similar to the lightened 505/38 with wide track which Piers Courage was driving.Last but by no means least, Matra have pursued a steady course of development since the beginning of the season. In the engine department their main problem has been with pistons, as already mentioned, and with their titanium connecting rods, whose high rate of expansion causes a tendency to bearing failure due to the hole at the big end growing too big.
Titanium is used widely on the chassis; practically all the nuts and bolts are of this material as well as the rear uprights on occasion. One attempt at weight saving, making the front brake calipers integral with the wheelposts, was not an unqualified success at Monaco; these have been perfected since, being used in conjunction with "turbo-fan"wheel discs for cooling on circuits where the braking condition is severe. Although designed round 13in. wheels, the Matras are now seen with 15in. rear wheels on fast circuits to prevent tyre overheating.
The remainder of the season should see the real struggle between the eights and the 12s. Now that the major problems with the Ford-Cosworth are mainly solved it is likely that Keith Duckworth will increase engine speed to more than 10,000 rpm to bring power output to the same as the 12s. It is reasonable to suppose that the 12s are now at the limit, so the battle will be on.
1: Ferrari followed the lead of Lotus by producing this 'slotted' wing, though it is adjustable only by trim tabs at the rear or by moving the two complete halves
2: Lotus found that the inboard front brakes of the 72 were drying out the oil in universal joints and burning the bodywork when the car stopped at the pits, so they developed this double fan arrangement to blow cold air over them .
3: McLaren are alone now in fitting 15-in. front wheels, which are used on Denny Hulme's car as he prefers the larger front brakes that they allow
above: The March 701 as it originally appeared. A car of this type (but without the aerodynamically shaped side tanks) took Jackie Stewart to vitHory in the Brands Hatch Race of Champions. At the Spanish Grand Prix the 701. first appeared with inboard rear brakes (inset), which involved a revision of the bottom suspension links and the Fitment of BRD sliding-spline drive-shafts. All the formula 1 Marches were subsequently converted to this specification. There are some differences between the cars of the various teams, notably in the tyres that they use. While the works cars run on Koni dampers, those of Ken Tyrrell and Antique Automobiles use Armstrongtop: The Lotus 72 in the latest form that Jochen Rindt used to win the French Grand Prix. This car has 'parallel' suspension front and rear, eliminating the original anti-dive and anti-squat characteristics. The second team carhas retained anti-dive ffont suspension which uses a different front sub-frame and pick-up points (see inset). The rear dampers were repositioned for the French Grand Prix to move them away from the exhaust pipes: they were previously mounted veitically, acting upon the rocker arm that tranmits the movement from the torsion bar. The inboard brakes, front and rear, have solid discs
4: 12-cylinder challengers to the long-held Ford supremacy. The flat-12 Ferrari of Ickx and the vee-12 Matra of Beltoise were well ahead of the opposition in practice and the opening laps of the French Grand Prix
5: The vee-12 BRM was developed into a race winner for the Belgian Grand Prix, where Rodriguez clearly had a power advantage over Amon's second-place Ford-powered March
6: The basically three-years-old Lotus 49 was still good enough to win the Monaco Grand Prix driven by Rindt, but Graham Hill's Rob Walker car has not been a front-runner in recent races. Walker's 49C uses the triple wing developed for the Lotus 72
7: The Brabham BT33 is the firm's first formula 1 monocoque and a typical piece of well thought-out but relatively simple design. Brabham won in South Africa and very nearly in Monaco. too. A new BT33 is to be fitted with inboard rear brakes
THIS Saturday Britain's premier motor sporting event, the RAC British Grand Prix, takes place at Brands Hatch. It is termed the "23rd RAC British Grand Prix," which assumes that the series started with the "RAC Grand Prix" at Silverstone in 1948, though there were of course equivalent races under different names held before the war at Brooklands and at Donington. The Grand Prix alternated between Silverstone and Aintree for several years and was first held at Brands Hatch in 1964. Since then Brands and Silverstone have shared the honours and the 1970 race is therefore the fourth Grand Prix to be held on the 2.65-mile Kentish circuit.
For the first time, this year's Grand Prix is really a two-day meeting, for the organizers have taken the lead from the Monaco Gra'nd Prix and decided to run an international formula 3 race tomorrow (Friday), the day preceding the formula 1 race. The whole meeting is organized by the RAC and sponsored by the Daily,Mail. The promoters have dispensed with the need for qualification to start -in the Grand Prix, a controversial, problem that has affected all but two of the preceding Championships rounds, by guaranteeing every entrant a start. This is beneficial not only to low-field competitors who have been missing the starting grids elsewhere by only tenths of a second, but' also to the spectators, for the British Grand Prix should see
the year's biggest formula 1 field with a probable 27 starters. The race is the seventh round of the 1970 World Championship and the final event in the first "half" of the series, from which the best six performances are added to the best five from the final six races to give the end-of-season Championship classification. In fact this is only of theoretical importance, as no driver or make of car has' scored in every race so far. With three wins to his credit, Jochen Rindt currently has an eight point lead in the Championship with 27 points to Brabham's and Stewart's 19 Denny Hulme and Chris' Amon share fourth place with 12 points. Lotus lead the Constructors Championship with 32 points to the 31 accumulated by the various March-Fords. Brabhams, in third place, have 21.
With two consecutive wins in the last two grandes epreuves, Rindt and the Lotus 72 start favourites at Brands Hatch. The circuit is reckoned to be a bumpy one as Grand Prix circuits go and this should favour the 72's unusually soft suspension, and Rindt feels optimistic about his chances there.
Whether Brands Hatch is 'an "eights" or a "twelves" circuit is more difficult to say. The French Grand Prix indicated that, while the cars keep running, the better 1 i-cylinder cars (in that case Ferrari and Matra) have the measure of the Ford V8-powered majority, and this on, a circuit where the wider torque band of the V8s was expected' to act to their advantage. What actually happened was that the V12s had a power advantage pulling out of corners and, particularly, up-hill. These are the same conditions that could give them the upper hand on the, twisty and undulating Brands Hatch circuit.
The BRM V12 was strong enough to win the fastest Grand Prix of all, at Spa, and has shown form since, notably in Holland. It has been dogged by a variety of troubles since Spa, but the Yardley sponsored P153s could be formidable contenders at Brands. Their winner in Belgium, Pedro Rodriguez, showed his rapport with the circuit in that magnificent win in the wet BOAC 1000 Kms sports car race, and Jack Oliver rates Brands Hatch his favourite circuit and led both this year's Race of Champions and the last Grand Prix there, in 1968.
The man who won the last Race of Champions back in March was World Champion Jackie Stewart, who at that time scored the first victory for the March 701. The car subsequently won the Spanish Grand Prix Stewart once again leads the Tyrrell team and will probably use the lightweight 701 that he raced at Zandvoort and Clermont. The works STP-backed March 701's should also be in a good position for they have Chris Amon (who is , if anything, showing better form than in previous seasons and must surely win his first Grand Prix soon) andJo Siffert who won the 1968 British Grand Prix in the Walker Lotus. And we are promised the appearance of Mario Andretti with the March owned by STP which should be very interesting. Widely considered as America's greatest driver, Andretti has still to find his feet in formula 1; his last appearance was at Jarama where he finished third. The British Grand Prix will be his first race in this country.
The current lap record holder (at 1 min 25.8sec, 111 .19 mph) is Jack Brabham who was robbed of victory in the Race of Champions bya faulty spark box, with only three laps to go. Winner of the South African Grand Prix, 44-year-old Brabham has a past Grand Prix victory at Brands to his credit, in 1966. His regular BT33 is currently undergoing modification to include inboard rear brakes.
At Clermont Jack was involved in a furious dice with his old team-mate Denny Hulme, back behind the wheel of the number 1 works McLaren M 14A. Hulme's burnt hands are steadily improving as his fine performance in France showed. He now has the backing of Dan Gurney, who scored one of the few victories for his Eagle formula 1 car at Brands Hatch three years ago, in the race of Champions.
The wide V12 Matras that went so well in France will once again be driven by Jean-Pierre Beltoise and Henri Pescarolo. John Surtees' new formula 1 car, the TS7, has been undergoing a good deal of testing in the past couple of weeks and looks promising. It will make its race debut on Saturday. Originally Surtees had also entered his McLaren M7C for Trevor Taylor to make his formula 1 comeback but this plan has been thwarted by a lack of engines.
Rob Walker had high hopes that he might have a Lotus 72 for Graham Hill by now, but the third car will not be completed in time aad he will race the well-used Lotus 49C once again.
Jacky Ickx is way down the points list at present but among the quickest Grand Prix drivers. He leads the Ferrari team and will on this occasion be partnered by Clay Regazzoni, the Swiss driver who finished fourth on his debut in Holland.
Other names who are driving formula 1 cars at Brands Hatch for the first time include John Miles (Gold Leaf Team Lotus 72), Rolf Stommelen(works Brabham BT33), Ronnie Peterson (Antique Automobiles March 701) and Francois Cevert (Tyrrell March 701). Canadian George Eaton once again has the third Yardley BRM and Andrea de Adamich the Alfa Romeo-engined McLaren, which could be another new M 14D if the chassis is ready in time. Though another McLaren was entered for Peter Gethin and Brabham had hoped to enter a BT33 for Tim Schenken's formula 1 debut, neither car is likely to be ready in time. One extremely promising driver who is to make his Grand Prix debut is the 23-year-old Brazilian Emerson Fittipaldi who has been entered by Gold Leaf Team Lotus in a 49C. If his performance in a single test session at Silverstone, when he turned a lap in 1 min 22.6sec (quick enough for second place on the grid at the International Trophy) is anything to go by, he .could be the surprise of the meeting.
Frank Williams had negotiated with Fittipaldi to drive the De Tomaso but/ at the time of writing has not nominated an alternative driver.
Brian Redman seems the strongest possibility. Making up the final three of this very large entry are American Pete Lovely's Lotus 49, Silvio Moser's Bellasi and a McLaren-Ford for Jo Bonnier, though what sort of McLaren this is is not known.
The entry indicates an extremely open race, but Brands Hatch has always been a circuit where experience counts.
The 20-lap Lombank Trophy Touring Car Race that precedes the Grand Prix is the ninth round of the British Saloon Car Championship. Al the usual contenders are there in the entry list, including the two 5-litre Boss Mustangs of Frank Gardner and Dennis Leech, Martin Birrane's similar but 7-litre car, and the Chevrolet Camaros of IT winner Brian Muir, Roy Pierpoint and David Piper.
During the lunch interval there is to be a cavalcade of Jaguar XK-engined sports cars to celebrate the 21 st anniversary of this power unit, and these cars will also be used for a parade iap of the formula 1 drivers before the Grand Prix.Practice for all the cars racing at the meeting begins today (Thursday) and the fastest formula 1 driver of the day will be presented with 100. bottles of champagne by the Evening News. Tomorrow's formula 3 race, which takes place in two 10-lap heats and a 20-lap final interspersed between the formula 1 practice sessions, promises some extremely close racing from the top names of this type of racing. As you can see, the entry list is enormous 84 cars with drivers from 17 different countries. It is not exactly anybody's race, but there are too many closely matched drivers in this highly competitive class to be able to predict a winner with much likelihood of being right.
And after it is all over, on Sunday afternoon, don't forget the Charity Cricket Match between the Grand Prix drivers and Lord Brabourne's XI. It is at Mersham Hatch Cricket Ground, 2 miles south of Ashford on the A20, and starts at 2.0 p.m. In aid of the Springfield Boys Club and the East Grinstead Hospital Mcindoe Burns Unit admission will be free but car parking will cost 10s.