Carlo Guzzi Supercharged 250C
With Phil Aynsley
Carlo Guzzi designed this supercharged 250cc machine in 1937, originally for record-breaking (although it did see some racing use) and it had a long competition career – running all the way from 1938 through to 1952.
The Cozette supercharger (manufactured by Guzzi) was gear driven and mounted above the gearbox. Depending on whether a petrol or methanol fuel mixture was used, output was around 38 hp or 45 hp at 7900rpm.
A large, cylindrical ‘expansion’ container was used between the carburettor and supercharger in early versions of the bike. This was replaced by a smaller chamber between the supercharger and inlet on later bikes. This model is fitted with the smaller chamber.
Record attempts began in April 1938 with Nello Pagani raising the 50km average speed record to 180.810km/h. Then in November Tenni Ombono set new 50km, 5 mile, 10km, 100km and 1 hour records.
More speed records were set the following year. The final achievement by the 250 was in 1952, when with a third wheel fitted and 60kg of ballast, it set a sidecar speed record of 221km/h.
In racing the 250 finished third outright in the 1938 Milano-Taranto and won the Italian Championship (both with Pagani riding). In the 1939 German GP the 250 beat the DKWs to first and second places.