Supercharged Ilahlla Capable of Over 95 m.p.h. TOUR1NG-CAR design, especially in the smaller classes, has nowadays reached such a pitch of perfection that with a certain amount of tuning, the cheap utility vehicle can be made to give a thoroughly

sporting performance. ‘the sports type Balilla Piet, a sturdy fourcylinder job with a three bearing crankshaft is very popular in Italy, and three of these 996 c.c. cars, fitted with attractive two-seater open bodies, put up an average of over 53 in.p.h. in the Italian 1,000 Miles Race. A similar car fitted with a high compression Siata o.h. v. cylinder head and four speed gear-box was driven by Ambrosini and Menchetti, and completed the same course at 55.33 m.p.h. This car was fitted with a streamlined coupé body. Ambrosini was so pleased with the performance of his Fiat Special that he decided to rebuild it as a racing car, and fitted it with a trim-looking single seater body. Using a supercharger in conjunction with the high-compression head, he succeeded in covering the flying kilometre at a speed of 145 k.p.m. (90 m.p.h.). Profiting by the experience which he had gained with the first car, he built another on the same lines, and entered it in the Monte Ceneri Hill-Climb. In the timed flying kilometre which begins the climb he put uto a speed of 151 k.p.m., and at one

point was doing 154, which is 96 m.p.h. The horse-power of the Balilla engine was raised from 22 at 2,800 r.p.m. to 38 at 4,000 with the Siata head, while the use of a Roots-type supercharger brought it up to 48 h.p. at 4,800 r.p.m. The supercharger. which was chain-driven from the front of the engine and geared up 1.25 to 1, was mounted on the right side, and fitted with a Cozette carburettor. The

compression ratio was 6.6 to I. Coil ignition was used, with a coil larger than standard. In order to improve streamlining there is no starting handle, but an electric starter

and battery was fitted. and was

Thermo-syphon cooling was used, and part of the radiator was blanked off. British components played their part in the success of the Balilla, for Castrol oil, K.L.G. sparking plugs and Rudge wheels were used. As will be seen, these were covered by aluminium discs.

A Siata 4 speed gear-box, which is specially made for sports Fiats, was used. The back axle ratio was 4 to 1.

The chassis. is the standard Fiat production but the chassis members were curved inwards and joined at the back, and a stout cross-tube was used to carry the rear spring shackles. The engine-gearbox unit was moved back 6 inches in the chassis, and the steering box was carried on the back of it with an ex

an extended shaft carrying the drop-arm. The steering wheel is of course in the middle of the car.

The body, as will be seen, is a neat single-seater, with a radiator guard, an undershield and a pointed tail. The exhaust pipe is carried round to the back. A 61 gallon petrol tank is carried in the tail, and the car complete weighs just under 10 cwt.