Sunday, 24 October 2010

Bevel drive DOHC - in 1924

This is probably the first engine to ever use bevel driven cams, the vertical tube and double overhead cambox looking remarkably like the Ducati 125 Desmo tested in Benzina #3 - but the Ducati came nearly forty years after this bike raced around the Circuito del Lario, the nearest thing the Italians had to a TT.

The bike's a Bianchi Freccia Celeste ("Heavenly Arrow") and it might have been the first motorcycle to feature DOHC, an idea pinched from the car world. The short stroke (71x81mm) 348cc twin gave 20bhp at 5,000rpm, a hell of an engineering achievement in 1924. But Bianchi had one further trick up their sleeve.

Bianchi's rider was Tazio Nuvolari. Because the early racer had a crude friction brakes (not replaced by drums until 1927, by which time power was up 20%) a lever throttle and hand gear-change, a very special rider was needed to make the most of the engine.

So, spend all the money on a bevel-cam engine, and then buy in a rider able to make up for other short-comings? Sounds like another source of Taglioni inspiration...

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