Corsica: a curse… and a charm
“I could devote several pages to the Tour de Corse, which seemed to be jinxed.…
4: 750 and 1200 Formulae
More than ever, money is the criterion in motor racing today. Starting money, prize money, trade sponsorship and bonuses, form a vital part in the successful activity of a professional racing team, making it more difficult all the time for the true amateur to join in with any chance of success, so we do perhaps tend to lose sight sometimes of the basic reason for taking part—that is the love of motoring sport, the thrill of competition.
We suppose that the hey-day of the amateur was in the great era of the Bentley Boys, when wealthy young men bought these heavy, powerful, expensive cars with their own money and competed with little thought of reward, simply with the idea of enjoyment and putting up a good show. Today the amateur is a rarity, if you define him as one who doesn’t get any sponsorship at all, and this strict but absolutely necessary rule governs competitions run by the Seven Fifty Motor Club, formed in 1939 to encourage owners of 750-c.c. cars to take part in motoring sport, and still run on exactly the same principles.
Naturally enough, the 750 MC doesn’t get very much race publicity, for the classes do not provide really spectacular racing, so, rather unfairly perhaps, many people tend to look down on clubmen’s racing. The Club does, however, provide its members with the chance to build their own cars at very low cost—as little as £70 can produce a race-worthy car and £250 can represent a race-winner– and race them purely for enjoyment. A set of secondhand tyres can last a season . . a pre-war 747-c.c. Austin engine can be picked up for 30 bob . . . someone may swap a chassis for an axle, or a pair of springs. Some members put aside £1 a week from their pay packet to pay for bits and pieces, and few of them invest more than £20 in one lump when they are building. It is a category where ingenuity can keep pace with expense, and the man who spends most is often embarrassed to find himself beaten by another who has some bright ideas about construction.
The spirit of competition was neatly summed up for us by Bryan Clayton, last year’s 750 Formula Championship winner, when he said : “You can spend as much as you like so long as you don’t win—then people start asking questions.” This is a very fair attitude, for it makes people very ingenious in their efforts to go one better than the next man, but if the Club think that a particular feature of a car costs too much tor the others to copy, in other words giving it an unfair advantage, it is quickly ruled out and status quo is restored. The 1200 Formula (it was recently called 1172 but now includes the o.h.v. push-rod engines) is more free regarding chassis construction, but not much more expensive in that cars can cost from £250 to around £400; last year’s Formula winner John Lancaster completed his season with a Ford 105E engine bought from a scrapyard for £20, rebuilt, modified at the top end only, and giving at least 65 b.h.p.
It would be quite wrong to assume that the cars taking part are a collection of refugees from a scrap-yard, for the workmanship and attention to detail usually shows a great deal of skill and pride, and lap times are quite competitive, as members prove when they take part in libre sports-car events. A good 750 weighs about 700 lb. on the start-line and the engine is producing about 50 b.h.p., giving a genuine ratio of 150 b.h.p./ton; a 1200 engine will give as much as 70 b.h.p. and the car will weigh about 800 lb., giving a possible 200 b.h.p./ton. This is about the same as a Jaguar E-type, for purposes of rough comparison, and we mention the fact to make it clear that this is a perfectly serious form of motor racing.
Amateurism is closely guarded. Competitors are not allowed to be sponsored and may not advertise, neither may any component maker advertise any success. Members are allowed to compete for prize money, though the situation does not often arise, and get no trade support. On the whole this preserves a much happier situation than is found in some other classes where the entrants and drivers get so jealous that, in the end, no-one gets proper recognition for good preparation and good driving.
The basic idea of the 750 Formula is to use an Austin Seven chassis, though how it is treated is left to the builder. The car must use the original rear springs and axle complete with differential and driveshafts. Until 1965 the use of the 747-c.c. Austin side-valve engine was also compulsory, but such was the unreliability that many people were on the point of giving up altogether and just when crisis point was reached, the Reliant alloy engine was admitted as an alternative. This has overhead valve-gear and a capacity of 600 c.c., but with .08 in. overbore, the maximum permitted, the capacity can be raised to 642 c.c. It is interesting to realise that the Austin engine can be persuaded to give 50 b.h.p., even with stipulations that the ports must remain siamesed, the camshaft can’t be run overhead, and of course supercharging is not permitted. Since none of the original parts are less than 30 years old now, and supply of the fragile crankshafts may dry up one day, the Reliant engine is bound to become more popular. This, too, is producing about 50 b.h.p. at the moment, though unlike the Austin it is restricted to a single carburetter with a 22-mm. flange, and it will rev to 8,200 reliably.
Bryan Clayton, who was the most successful 750 man last year, is a bearded stockbroker’s clerk who has been studying engineering at evening classes for rather a long time—not surprising, really, since an excellent set of lathes are provided and several other club-racing men go along a couple of evenings a week carrying heavy holdalls. He started racing in 1962 with Vitesse I, a 750 Formula car, and in 1964 this was replaced by Vitesse II the present machine, still powered by an Austin engine. In 1964 he blew up four engines, and while they are easy enough to replace the process was so dispiriting, and so much time was used up, that he would have retired by now but for the Reliant. The cheapest Reliant engine costs about £30, or £70 new from the factory, and in its first year did not score an outright win at any event as various people were thinking of ways to get it to deliver the right sort of power. A target of 60 b.h.p. is in mind now and it would be a great achievement to better 90 b.h.p. /litre with a heavily-choked 4-cylinder production engine. A 4-speed close-ratio Austin Seven gearbox is mated to the engine by means of Clayton’s special adaptor, and a competition clutch is used.
The chassis is from a 1934 Seven, at least the side-members are, boxed in for extra strength. The structure is built up into a space-frame using various section tubing. The original 1/4-elliptic springs are used at the back, remade and located by A-brackets, and drive is via a hybrid axle with an offset differential (5.625 ratio)—this is achieved by pairing longer and shorter pre and post-1931 half-axles, resulting in an offset transmission line through the cockpit. Morris Minor brakes are on the back, the system having twin master cylinders. Front suspension features Triumph Herald uprights (and brake drums), unequal length wishbones, and inclined coil spring/damper units.
Aluminium bodywork is fitted, with a glass-fibre nosepiece, and the whole car weighs 702 lb. ready to race. Normal production steel wheels are used, from a Herald with 4-1/2J rims at the front, and reversed Ford 105E 5J wheels at the back, of 13 in. diameter—Dunlop R6 racing tyres lasted the season, and the front tyres would probably last two seasons if necessary.
The car cost £330 to make, although Clayton thinks that he can build the next one for £250. It raced 18 times in 1966 and had nine wins, though one was disallowed due to a push-start. It also had a second, a third, and a sixth, and four retirements—one due to a dropped valve after over-lightening, two due to the ensuing complications, and one because of a broken half-shaft.
We mentioned an output of 50 b.h.p., achieved by a number of means. Having overbored to 640 c.c., Clayton made his own pistons from blanks (serious evening institute study), reground the crankshaft and lightened the flywheel. The Regal alloy head was reshaped, the compression ratio increased to 11.5 to I. but standard-size valves retained. Rocker gear was lightened and the camshaft reground to give more lift, and the timing was altered. A Weber 321MPE carburetter was fitted to the original manifold with a 22-mm. restrictor worked in.
In this state of tune the car is capable of lapping the Silverstone Club circuit in 1 min. 20 sec. and the Brands Hatch short circuit in 68 sec. It will achieve about 98 m.p.h. in top gear with its present axle ratio, and has certainly established itself as the most reliable car of the year—Bill Cowley was very fast in his Austin-engined special, but less reliable, and Jim White’s Austin-powered car was runner-up.
At the end of the season Clayton sold the car for £295, the most anyone has paid for a 750, and put the money down on a new house. He is building a new car, of course, which should be about the lowest ever built for the Formula. The Reliant engine is inclined 10 deg. from horizontal, requiring dry-sump lubrication, and now it is completed the chassis even makes 10-in. Cooper S wheels look large! It will probably weigh about 6 cwt. and the cost will be in the region of £250; tubing for the chassis costs about £10, but it takes at least a fortnight to build up and another month to hang the brackets on. To anyone thinking of doing this, both Clayton and John Lancaster say that a lot of thought is required, and the amateur must be prepared to overcome his basic mistakes (that, it seems, is the fun of it)!
Vitesse II was returning about 12 m.p.g. when racing, and the two Champions both reckoned that it costs them about £5 in entry fees, petrol and sundries when they do a meeting. At that rate, Clayton’s entire season cost him £110, and the car depreciated £35 in two seasons, so there is no doubt that this is by far the cheapest way of going motor racing seriously.
Lancaster was equally helpful in telling us about the old 1172. Formula (the title has just been changed), of which he came out Champion by the narrowest of margins from Bryan Small’s 1,000-c.c. U2–one point separated the two after nine meetings, and still there was a one-point margin after the best seven were taken into account. As with the 750s, the 1172 class showed much more reliability when better, o.h.v. engines were admitted, and this has certainly made a difference to the support.
The Championship winner, a 29-year-old production development engineer, actually designed and built his first car when he was 16 (“It took a couple of years because I made so many mistakes.”). Then an apprentice engineer, Lancaster entered some 750 M.C. meetings in 1958 and won the Novice Trophy. The car cost about £150 to build and he sold it in 1960 for £170, when he designed a new space-frame 1172 car with riveted panels, a sort of monocoque. This went on the road in 1961 and was raced the following year but not very successfully as the independent rear suspension didn’t work too well owing to the hubs being too flexible. A rigid axle was fitted in 1963 but unreliability with the Ford 100E was the greatest bugbear as cylinder heads and gaskets gave way one after another. By 1964 the car was more reliable, actually finishing three meetings without the engine being touched, but during the season John’s elder brother, Reg, wrote it off in a spectacular accident. Up to that time it had a total of about £400 spent on it.
The Orva Mark III, built during 1965, used many parts from the earlier car and cost another £200 to complete. It was designed to the last detail on a drawing board, making use of the much freer construction requirements of the 1172 Formula. The only real stipulation is a minimum cockpit width of 32 in., resulting in the construction of quite orthodox, wide racing cars. The Mark III has D-tube stressed centre sections with front and rear sub-frames. All independent suspension is used with Herald uprights at the front, with much altered Fiat 1100 rear brakes, and Lola Formula Junior hub carriers at the rear. Reg Lancaster made the differential from the axle of a Morris Minor (5.125 ratio) and the complete car weighs a fraction over 7 cwt.
After the accident it was felt that light suspension was a useful feature, in that a wheel may be torn away without damaging the main structure, and this has since proved true. In constructing the Orva Lancaster was able to salvage the 100E engine and save money, so in a rare spending spree he spent £40 on a set of magnesium alloy wheels and, from the tone of his voice, regretted it ever since. A B.M.C. A-series gearbox with Lotus close-ratio gears cost £20, but a fault cost £11 to rectify, so this was an expensive investment too. Second-hand Herald uprights with hubs carrying disc brakes cost £16, again considered pricey, completed the construction, and on the car’s first outing at Brands Hatch in April it won the event—as its owner says it was a much better car.
At Snetterton a fortnight later the engine finally and conclusively blew up, so Lancaster borrowed an ex-scrapyard I,000-c.c. 105E engine from John Clark; this ran badly at Castle Combe in June due to poor carburation, but investigation into Cosworth’s plumbing on a Formula Three engine gave a few clues and since then the engine has run extremely well. Taking the seven best Championship scores, Lancaster had three wins, three second places and a third.
Purchase of the Ford engine cost £20, a Cosworth A6 camshaft cost £18, balancing cost £5, and frequent replacement of the main bearings also increased the cost £65 and the gearbox another £15 (in maintenance), Castrol R cost £10 and, calculating nine races at £5 each, including entry fees and travel, the running costs for the year amounted to £135. If the engine proves reliable this year, as a good 105E should, the season could work out a good deal cheaper and the average cost of 10 races could work out at £10, working on top limits. The only improvement work being done on the car is replacing the production crankshaft by a solid one, as the hollow crank has so far performed above expectations.
By limiting the choke size to 28 mm. on the o.h.v. Formula engines the 750 MC have effectively checked engine development. In other categories this is not a good thing, obviously, but club-racing men cannot afford to indulge in expensive development programmes, only the very basic variety. John Lancaster’s engine, giving 65-70 b.h.p., is presumably one of the best yet it runs standard-size valves, and a detuned Formula Three engine has not yet proved superior. As Lancaster proved, the basic 105E engine will run up to 8000 r.p.m with a standard crankshaft, pistons, con-rods and valve gear, so it is not vitally necessary to go out and spend a fortune for this type of racing. His car, incidentally, is not exactly slow since it will lap the Silverstone Club circuit in 1 min. 12 sec. and pull 116 m.p.h. on the G.P. circuit, and lap the short circuit at Brands Hatch in 61 sec.
From small beginnings, the saying goes, come great things. Colin Chapman, Eric Broadly, and Eagle designer Len Terry all cut their teeth on Formula racing, as did Mike Costin, Peter Boshier-Jones, Jem Marsh and a good many more prominent names.
Seven-Fifty racing can be summed up as minutes of pleasure interspersed with hours of disappointment and days of tramping around breakers’ yards. No-one claims that it is a breeding ground of great drivers, though in some instances this proves the case, but for everyone actively involved, more especially if they don’t have great hopes, aspirations, or bank balances, it is a fulfillment and great fun. Through the Club magazine the more successful competitors are constantly passing on their knowledge so that the youngest novice can make a tolerably successful start with constructing his own car and, from what we have seen, there is a very friendly and helpful atmosphere prevailing. We receive a good many inquiries about the Club, the secretary of which is Colin Peck at Dancers End, St. Winifred’s Road, Biggin Hill, Kent (Biggin Hill 2004). — M.L.C.
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