PRESENT-DAY RACING CARS

PRES °NT-DAY RACING CARS

III. -THE DERBY-MILLER

FOR several years now the development of the motor-car in America has been on strictly utilitarian lines, and the United States possesses no firms of sporting repute to compare with Bugatti or Alfa-Romeo. Racing there mainly consists of board track events, and of course, the annual 500 mile race at Indianapolis. Millers, with their front-wheel drive layout, have been conspicuously successful in these events, and in the hands of Mrs. Stewart the DerbyMiller, a modified version of the original car, has performed equally well at Montlhery.

Mrs. Stewart’s car was bought in 1930 by Mr. Hawkes, and already had a good record behind it, having put up a speed of 139 m.p.h. on Altoona Speedway. It was brought to Europe and raced without alteration, but being designed for the smooth board tracks of America, it was found not to be strong enough to withstand the pounding of Montlhery, and has since been modified until little of the original car remains. The engine is a straight-eight, originally fitted with cylinders of 56.6 x 76.20 mm., giving a cubic .capacity

of 1,480 c.c., but now run with various blocks and pistons, the usual size being 59 x 76.5 or 1.673 c.c. The crankshaft runs in five plain bearings, and the tubular steel connecting rods have plain big-ends. The valves are operated by two gear-driven overhead camshafts, which actuate the valves by means of steel pistons. Following the usual practice of American racing cars, the supercharger is of the centrifugal type, and runs at 40,000 r.p.m. Considerable trouble was experienced with the ball bearings, but a comprehensive system of forced lubrication and the fitting of a third bearing has overcome the difficulty.

Other alterations to the original unit include a modified and very much stiffened-up crankcase, re-designed main bearings for the crankshaft, and new type connecting rods and camshafts. The engine runs at 6,500 r.p.m. The plate clutch has not given any trouble, probably because a positive drive comes into opera6on when it is fully home. The gearbox, while doubtless satisfactory for the rolling starts in vogue in America, was not strong enough

to withstand the strain of standing starts, and had to be re-designed. It still has three speeds.

The front-wheel-drive mechanism, the salient feature of the Miller, has behaved well. A tubular front axle connects the two stub axle pins, and two universal joints between each driving shaft and wheel overcomes the ” flick ” which occurs on a lock with only one universal. The rear axle is tubular, and a slot in the petrol-tank allows of free movement. Incidentally, the Miller frontwheel-drive mechanism forms an excellent instance of the value of racing in developing new inventions, for it is used almost unchanged in the Cord cars, and largely due to experience gained with this type of transmission, a very simple and effective front wheel drive lay out has been evolved for the new Derby car, which is manufactured by Mr. Hawkes. The Derby-Miller has had a very successful career in France. Mrs. Stewart has held the following records :

World’s record for 10 miles, flying start, at 137.21 m.p.h. (220.810 k.p.h.), and the 100 and 200 kilometres records at 206 and 195 k.p.h. respectively, an amazing performance for a 1 litre car. She also holds four records in Class E (1,501-2,000 c.c.) the 5 km., 50 miles, 100 miles and the coveted one-hour record. In Class F she holds the 200 kilometres, 100 miles and again the hour. On Montlhery the car has reached 142 m.p.h.

World’s 10 miles (f.s.), 137.21 ; 100 kms. (s.s.,) 206.1; 200 kms. (s.s.), 194.9. Class E., 1,501-2,000 c.c. ; Smiles; 5 kms. ; 10 kills. ; 10 miles ; 50, WO, 200 kms. ; 1 hour. Class F., 1,100-1,500; 200 kms. ; 100 miles ; 1 hour.

The record in class E for 5 kilometres is the fastest is the world, apart from straight-rtm two-way records, being at a speed of over 140 m.p.h.

The 10 miles World’s Record of 137.21 m.p.h. has recently been beaten by Norman Smith in New Zealand on a car ten times the size, and on a straight run on the open beach.

As has been said, the car has been stiffened up all round, and the weight has actually been put up 3 cwt. by these alterations. It is not yet suitable for Brooklands, but the suspension has been re-designed, and Mr. Hawkes hopes to bring over the Derby-Miller later in the season.

“We did not have much hope last year,” he said, “as the car was brought over in bits and put together on the spot.”

” Brooklands is very rough, and so far the track record has always been held by a heavy car,” he continued, “but I am convinced that the Derby will be successful. With front-wheel-drive at Montlhery we found that we could drive high or low on the banking as we desired, and it will overcome the difficulty of getting off the Byfleet banking which all high-speed cars experience.”

Unfortunately, Mrs. Stewart has had to undergo an operation lately, and will not be fit to drive for a month or more. She hopes to make an attempt on the World’s Hour Record, and Mr. Hawkes is convinced that she can get it, even if it is set a little higher than the present figure, by the time Mrs. Stewart is able to drive again. Please :mention MOTOR SPORT