Fiat’s wonderful Centro Storico museum in Turin contains an example of every product it has made, from ships, tractors, trams, railway locomotive and stock, aeroplanes, aero-engines to racing and ordinary cars, etc, many in accurate one-fifth model form. When I was exploring it in 1969 I recognised the remarkable engine used in 1934 to gain the World’s Air Speed Record for Italy, in a Macchi-Castoldi MC72 seaplane flown by Lt Francesco Agello at 440.681mph. It was not surprising that I had spotted it as it was 11ft long!
Fiat made engines for the famous Schneider Trophy races under contract to the Italian air ministry, and the AS6 was designed by Tranquillo Zerbi, of Alfa Romeo racing car fame.
To attain more speed after the 1929 Trophy, won by the British Supermarine S6 at 328.65mph, there were two options: to increase the power of an existing engine or to reduce air drag. Rolls-Royce chose the former, Fiat the latter expedient. Both used 60-deg V12 engines but Fiat’s had a lower frontal area. The drag of seaplane floats reduced speed but had to be used as aerodromes were not long enough for aeroplanes of such pace. The Fiat AS6 had two AS5-type engines in tandem, not coupled, driving contra-rotating propellors by separate shafts. By 1934, it produced 3300hp at 3100rpm, a centrifugal supercharger, running at 19,000rpm, serving both engines.
Fiat also gained from the small size of the contra-rotating props. Rolls kept to its R-type engine, gaining power with high blower pressure.
Before the 1931 Schneider race, Fiat had problems with the supercharger drive and burnt valves, which took three months to cure. R-R had difficulties with lubrication, the s/c drive and blow-back, etc. Bank’s very special fuel gave the R-type engine, forerunner of the Merlin, a power output of 2350hp for the 1931 race.
Britain had beaten Italy in this important race since 1926, and it was felt vital for her to win the last of the series in ’31, and thus outright ownership of the Schneider Trophy. Britain’s Labour government refused to enter, as a cost of £80,000 was deemed too high. This became a long political struggle, and even Italy and France appealed for British competition. But when Lady Lucy Houston, Britain’s richest woman and a noted patriot, put up £100,000, the 1931 race was on. But Italy and France non-started and we had only to complete the race distance of seven 50km laps above Calshot water to win. Flt Lt Boothman averaged 340.08mph in an S6B: victory was ours.
Vast crowds watched in spite of the one-machine race, and the BBC did a radio commentary. To give them more to see, Flt Lt Staniforth then took the ASR to 379.05mph, soon improved to 407.5mph. With another of Banks’s exotic fuel mixes another S6B raised this to 415.20mph before September 1931 was out. The Italians took until ’34 to beat this.
What has this to do with motor racing? Nothing, except that if you are in the Southampton area, I think you can still look at an S6B in the Mitchell Memorial Hall, and perhaps the old House of Commons’ debates about air-racing might be revived, to try to get Mr Blair to provide sponsorship to enhance British prestige in racing.