To certain irreverent people, the orthodox Indianapolis "500" racing car is a dinosaur. Though it has ruled Indy for a decade, the Offenhauser-engined, solid-axle roadster is away behind the times, they say, and headed for certain extinction.
A startling event the other day seemed to prove the heretics right. With eight exhaust stacks pointing impudently skyward, a small, rear-engined, independently sprung racer whistled around the 2�-mile Indianapolis Motor Speedway at a speed of 150.501 mph. It was the fastest lap save one ever reported at Indy. The fastest, turned in qualifying trials last year by Rufus Parnell Jones in a conventional Offy roadster, was the merest touch quicker: 150.729 mph.
All sorts of remarkable things surround the pagan intruder. It was driven not by a "500" veteran but by the American road racer Dan Gurney, who drove his first "500" only last year. There had been much experimenting with tires and gear ratios; the 150-mph lap was but one of three in which Gurney was trying for real speed during a six-lap practice test for one of those tire-and-gear combinations. Gurney was already on the following lap and backing off the throttle, preparing to come in, when the pits signaled his 150 mph. Thus the racer appeared not to have been fully extended. Moreover, the track was innocent of the speed-enhancing rubber that will be laid down by the full Indy field next month when official practice begins. "Basically," said the tall, handsome Gurncy, who is given to understatement, "we are in very good shape."
The car is a joint work of the Ford Motor Company and Britain's Colin Chapman, builder of the famous Lotus racing cars. Gurney ignited the collaboration last year. A patriot, he thought the "500" a logical event for American V-8 power (and indeed catch-drove a Buick-engined V-8 for the California speed merchant, Mickey Thompson, in 1962). A believer in the European design principles which now govern Grand Prix cars, he saw Chapman as "the No. 1 design brain in racing, a creative genius."
Ford has handcrafted a lightweight aluminum engine to Indy's 4.2-liter maximum displacement to power a typically frameless, superlight, rocket-slim Chapman chassis. The engine weighs only 350 pounds. It develops one hp per pound and is believed to be the first racing engine to reach that peak of efficiency. Unlike the four-cylinder Offenhausers, it is neither fuel-injected nor fitted with overhead racing camshafts, nor does it burn racing alcohol. Four twin-throat Italian Weber carburetors are used rather than direct injection. As in most passenger car engines, valves are pushrod-actuated. Most startling is the fact that ordinary premium pump gasoline—the kind any motorist can buy—is the racer's fuel. Alcohol is the usual Indy fuel.
Ford and Chapman could go to alcohol. But with gasoline and carburetion they have already produced an astonishing lap speed. They may also have achieved a rate of fuel consumption enough lower than that of the thirsty Offies to run 500 miles with but one pit stop if—and it's a big if—tire wear permits. The Offenhausers normally make three stops for tires and fuel.
Chapman's chassis, weighing only 1,130 pounds with the Ford V-8 aboard as compared with a good, light Offy's 1,500-1,600, is, like his monocoque Grand Prix car, essentially a stressed-skin gas tank on wheels. Power is transmitted to the rear driving wheels through an Italian Colotti gearbox.
Actually, the racer seen at Indy was only a prototype of two entries which will be driven in the "500" by Gurney and Chapman's stylish team driver, Jimmy Clark of Scotland. Clark, in a brief stay at Indy, gunned the prototype up to 146 mph before Gurney spiraled on to 150. The prototype was symmetrical. The chassis of the two new racers will be offset—nearer the inside wheels, Indy style—to reduce tire wear.
As if the Lotus-Fords were not heresy enough, Mickey Thompson will invade the qualifying trials with five rear-engined cars. All of these will have aluminum Chevrolet engines, and it will be worth any enthusiast's time to be at the Brickyard May 18 and 19 for the first qualifying weekend, if only to enjoy the shock waves of this unprecedented Ford-Chevy collision. Three of Thompson's racers look like streamlined Go-Karts, having sensationally small wheels—12 inches in diameter—and wide-footprint tires. The standard Indy wheel measures 16 inches. The other two are Thompson 1962s, but with Chevy engines. And Sportsman Jim Kimberly is bringing in two Buick-engined Thompson '62s.
Since Thompson's drivers include the world Grand Prix champion Graham Hill of England and the American Grand Prix leadfoot, Masten Gregory, the best of the international road racing corps will be involved, at last, in the world's foremost track race.