The way we were: September


Bianchi’s supercharged 500cc four-cylinder

If financial constraints were a consideration, The Motor Cycle suggested the annual car and motorcycle shows be amalgamated during the war.

Interest in multi-cylinder machines was heightened after their many successes across Europe, including at the Ulster GP. Italian maker Bianchi unveiled its new supercharged 500cc four-cylinder racer (above) to the international press. The dohc transverse four had an internally lubricated fully enclosed shaft drive to its enclosed twin camshafts and open valve springs.

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Of unit engine/gearbox construction, the magneto was mounted above the gearbox. The downdraught carburettor fed by the supercharger forced fuel mixture into the cylinders via a ribbed manifold.

A huge, almost pistol-grip like fuel tank was traditionally mounted above the triple-top tube frame with single front downtube and saddle tube and duplex cradle under the engine/gearbox unit. Plunger rear suspension was employed with a sprung front fork sporting, unusually for racing motorcycles, pressed steel blades. Front suspension control was by single compression coil spring and hand-operated friction dampers to both sides of the fork’s lower links.

Although the frame was massive, weight was saved by the use of light alloy for all engine, supercharger, drive cover and wheel hub castings. Final drive by chain was on the right and it rode on 3.25in tyres.

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First unveiled at the 1938 Milan Show, the 70/75bhp @ 8/9000rpm machine was first tested in Italy towards the end of 1938. Further development led to the machine depicted here and it was planned the design team would further refine the model before racing it internationally.

In a race of many retirements, Welshman Selwyn Griffiths (Matchless G50) won the Senior Manx GP from Scot George Buchan (Norton) with Mike Kelly (Norton) third. Malcolm Uphill had been a member of the leading group until he ran out of fuel at the Mountain Box on the last lap. David Williams (MW Special) secured Junior victory from Uphill, and Gordon Keith (Greeves) the Lightweight race from Rex Butcher (Aermacchi).

Donington Park hosted the year’s British round of the Grand Prix series. In the 500cc class, fans watched American Kevin Schwantz (Suzuki) race from pole position to winner’s rostrum by less than a second from fellow American Eddie Lawson (Honda) with Wayne Rainey (Yamaha) eight seconds adrift in third place.

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