The McLaren-Oldsmobile

The trend of fitting large capacity American push-rod V8 engines in European style chassis, both single-seater and sports-racing has come back into vogue after a period of being non-u due to the success of such cars as the Lotus 19 and Cooper Monaco with 2½-litre or 2.7-litre Coventry-Climax 4-cylinder engines. The Climax powered cars used to run rings round the bigger cars by virtue of their far superior roadholding, as the people who put V8s into existing chassis often just dropped the big cast-iron engines into the chassis with no modification at all—with the result that handling was not quite what it should be.

The situation has been changing this year and such cars as Jim Hall’s rear-engined Chaparalls with automatic transmission and Carroll Shelby’s King Cobras (Cooper Monacos with Ford V8 engines) have been cleaning up in American sports car races: Despite the difficulties involved in obtaining American engines in this country the trend is spreading rapidly to Britain and many cars now sport big V8 engines, both in the hill climb and sprint world as well as in racing. We even have several production cars fitted with American V8s, including the Bristol 408, the Jensen C-V8 and of course the A.C. Cobra and the Sunbeam Tiger. Home brewed V8s are used by Daimler and Rolls-Royce and on the Continent Facet Vega and Iso Rivolta use American V8s in their GT cars. Both Mercedes-Benz and Maserati use V8 engines of their own design with Ferrari using a V12, and the vee engine in V4 and V6 form is used by Lancia and as a V6 by Ford of Germany in the new Taunus 2oM (an engine which many people believe will be used in the Ford Zephyr before long). This seems to indicate a gradual but growing gravitation towards the vee engine for production cars in Europe and it cannot be too long before one of the British mass producers comes out with a fairly large capacity V8.

The argument against push rod engines in racing has always been that they lack reliability when compared with their more sophisticated brothers with numerous overhead camshafts. There is undoubtedly some substance in this if the engine is merely a hotted-up version of a standard V8 but an engine built up from scratch for racing seems to be as durable as the pukka racing engines. The Lola-Ford prototypes looked as if they would prove this, but were let down by gearboxes in long distance races, but the Lotus 295 went the distance at Indianapolis in 1961; and of course the Shelby Cobras are still chasing Ferrari hard in the GT Manufacturers Championship,

One of the greatest protagonists for American engines in Britain at the moment is Bruce McLaren, who has just completed the first sports/racing car to bear his name, and which, by the time this appears in print, will have competed in its first race at Mosport. Canada, Prior to doing the American “season” at Riverside and Laguna Seca and then the Nassau Speed week.

His interest began when he purchased the Zerex Special from Roger Penske earlier this year. This Car, known in America as the “cheater special,” because of the way Penske had made what was virtually a Formula One Cooper into a sports car, Was extremely successful in Penske’s hands with a 2.7-litre Coventry-Climax engine, but the V8s were already beginning to catch it when McLaren bought the car. He had a couple of easy wins with the car at Silverstone and Aintree (where Jim Clark finished second in the Ford V8-engined Lotus 30 after starting from the back of the grid) but he realised the shortcomings of the car and rebuilt it with a completely new and stiffer chassis frame and a 4-litre Oldsmobile engine in the back. Once again victory came its way, both at Mosport in June and in the Guards Trophy race at Brands Hatch. However, by now Bruce McLaren had quite a few more ideas on how to improve the car and the decision was taken to build a brand new car incorporating the ideas learned from the Zerex Special. Bruce McLaren Motor Racing Ltd. was already in existence, having been formed in 1963 to enter cars for the Australian winter season, and Bruce McLaren was joined by Teddy Mayer, brother of the late Tim Mayer, to manage affairs in Bruce’s frequent absences on Formula One duties with the Cooper team. Large, spacious and well-lit workshops were acquired in Feltham, near London Airport and in fate July work commenced on the new cat, which was due to take part in the Mosport race on September 2oth, less than two months ahead. The sketches for the design were made by Bruce McLaren who then handed them over to former Cooper designer Owen Maddocks to carry out the engineering drawings. This completed, the work of transferring it 1010metal was handed over to New Zealander Wally Willmott and American Tyler Alexander, who have made many detail modifications as they have gone along.

The car has a simple-looking tubular steel frame with large diameter, light gauge tubes as the main chassis members, with 14 gauge magnesium sheet riveted -and glued beneath the chassis as an undertray and strengthening member. Bulkheads are fitted at the front and rear of the cockpit, the forward one being a fabricated steel structure and the rear one being a simple cross braced tubular hoop. Further bulkheads are fitted at the extreme ends of the car for the front suspension, radiator, etc., and for the rear suspension, and gearbox; these are also of fabricated steel structure for strength and lightness. The top chassis tubes take water to the engine but no oil is transferred in this way as the engine uses a wet sump and no oil tank is fitted. The Chassis frame is remarkably low, being only 10 in. deep, which allows various engines to be fitted but must make for difficulty in obtaining lateral strength and resistance to twisting loads. Suspension is fairly conventional, with the front layout being by lower wishbones with single top links and long radius arms locating on the cockpit bulkhead. An anti-roll bar is fitted and the rack and pinion steering is fairly high mounted. The rear suspension uses lower reversed wishbones, single top links and very large diameter double radius arms, in conjunction with Cooper cast alloy hub carriers, The anti-roll bar is rather unusual in that the bar is clamped to the chassis beneath the gearbox and the operating arms extend upwards, being attached to the tops of the hub carriers. Armstrong coil spring/damper units are fitted all round.

The fuel is contained in two long saddle tanks which are mounted on brackets either side of the chassis. These are made of 18 gauge aluminium covered in glassfibre, hold a total of 40 gallons of fuel and are shaped so that the rear radius arms pass through them. A change-over switch is fitted on the cockpit floor in the centre so that the driver can keep a good balance between the contents of the two tanks throughout at long race.

The engine of the car at present is a 4-litre Oldsmobile modified by the Californian speed shop of Tracts Engineering who build many of the engines which power the fastest sports cars, such as the Chevrolet engines used by Jim Hall’s Chaparalls and Roger Penske’s cars and the Ford units used by Dan Gurney. This particular engine gives 315 b.h.p. hut on arrival in Canada it was due to be fitted With a 4½-litre Oldsmobile engine giving a power output of around 380 b.h.p, This engine is of course not merely a hotted-up production unit but a carefully built up unit with only racing in mind. It is of all-aluminium construction and fitted with four downdraught Weber carburetters. These engines weigh about the same as a 2.7-litre Climax and of course deliver far more power, as the Climax gives about 250 b.h.p. They also cost about the same, and a fully modified V8 like the one fitted in the McLaren can be obtained for around £1,500, £300 of which goes on the four Weber carbs! What is more revealing is that the McLaren team has found the V8 to be more reliable than the Climax fours as it is capable of going for hundreds of racing miles without attention. Another interesting triumph of production parts over special racing components is the radiator, which is a standard Chevrolet Corvette radiator, weighing half as much as a racing radiator and costing far less. The engine drives through an American racing clutch to a Hewland 5-speed HD4 gearbox, which is mated to the engine by a huge bell-housing, and has so far stood up to the power of the engine without protest. One of the big problems with cars having powerful engines at the rear is to get a gearbox to withstand the power; it looks as if Hewland have solved this problem. Bruce McLaren seems convinced, for he is replacing the Colotti gearbox on his Tasman single-seater with a Hewland HD4.

Drive shafts are another problem, and the McLaren follows Cooper practice by using shortened Mercedes-Benz splined shafts as used on the Cooper F.1 cars and as tried by Lotus recently. Girling disc brakes are fitted all round, with twin master cylinders for safety. Wheels are Cooper 15 in. with 5.50 x 15 in. tyres at the front and 6.50 x 15 in. at the rear. The spare wheel is mounted in the nose of the car over the driver’s legs.

The body, complying with Appendix C, was designed by Tony Hilder and was carried out in aluminium by Peel’s of Kingston. The cockpit is kept simple, with only an 8,000-r.p.m. tachometer, oil and water temperature gauges and an oil-pressure gauge being fitted in the sheet magnesium facia panel. The driver and passenger have unpadded glassfibre seats but should a passenger be carried his feet would be rather cramped as the chassis sweeps inwards on the left side. The gear level is on the right-hand side of the cockpit mounted on the top chassis tube.

The car was taken to Goodwood soon after being completed and Bruce McLaren took the completely untried car round some 2 sec. quicker than the sports-car record, which augers well for the future. No doubt orders will come in for replicas of this car but the design will be proved first before customers receive cars. In any case, the mechanics will be away looking after the first car at its various races for some considerable time. The old Zerex Special is being rebuilt and has been sold back to America and the team is also busily engaged in rebuilding Bruce McLaren’s single-seater for the Tasman series, while the Cooper works is building a new car which will be driven by Phil Hill in the series.

Just as his Cooper team leader, Jack Brabham, left to build cars under his own name, so it seems that the Cooper team will eventually lose their No 1 driver and the name of McLaren will be seen on the entry lists as well as a driver. – M.L.T.