The two practice days saw immense activity as the regulations permitted only the 24 fastest cars to compete and 34 were present to do battle. On the first day the new 2-litre Cisitalia eliminated itself quite unintentionally by scattering a rod and most of its crankcase over the track; this was an o.h.v. four-cylinder, with four Del Orto motor-cycle carburetters, mounted in a typical Cisitalia multi-tube chassis with independent suspension all round, transverse leaf spring and wishbones at the front and a combination of radius tubes and wishbones at the rear, with he outer universal joint of each half axle mounted in the wheel hub. Although the car was reputed to be new the outward appearance was that of a well-used model. Bill Aston could not get the Butterworth half of his Aston-Butterworth to function properly and was slow in consequence, while neither of the "works" H.W.M.s nor Gaze's private car could produce enough speed.
When practice finished on Saturday evening there were nine disgruntled drivers who were ruled out--all three H.W.M.s (which was a very unhappy occurrence in view of their past records), the 12-cylinder Ferraris of Whitehead and von Stuck, the latter car belonging to the Ecurie Espadon, the Belgian-owned four-cylinder Ferrari, Crespo and Graffenried with the Maserati-Plates and Aston. An idea of the closeness of this eliminating was shown by Ancari's fastest lap in 2 min. 5.7 sec. and Stuck with the slowest in 2 min. 22.8 sec. The last man to qualify was Bianco (Maserati) with 2.inin. 17.1 sec., and just over 5½ seconds covered the nine cars that were ruled out.
The starting grid consisted of five "works" Ferraris, all four-cylinders of the latest type, driven by Ascari, Villoresi, Farina, Taruffi and Simon, the French trio, Manzon, Trintignant and Behra on Gordinis, Gonzalez, Bonetto/ and Rol with the new "works" A6GCM Maseratis, Landi, Bianco and Cantoni with the Scuderia Bandierantes A6G Maseratis, Rosier and Fischer on their private four-cylinder Ferraris, and Bayol with a Very pretty new six-cylinder 2-litre O.S.C.A. with normal O.S.C.A. i.f.s., a de Dion rear end hung on splayed ¼-elliptics not unlike last year's H.W.M.s but with inboard brakes and differential-mounted gearbox. Last but by no means least were three Cormaughts, looking clean and new and a credit to any country, driven by Moss, Poore and McAlpine, and four well-tried and proven Cooper-Bristol driven by Hawthorn, Brandon, Brown and Wharton. the last being the Ecurie Ecosse car. Moss, by reason of one of the cleverest pieces of slip-streaming behind Ascari, had got a practice lap in at 2 min. 9,8 sec., while the "boy-wonder" Hawthorn made his Bristol engine take him round in 2 min.11.2 sec. and then made his father endless work by having a gasket collapse.
