Moto Guzzi 250 Single-shaft & 250 Compressor
Racing Bikes Moto Guzzi 250 Single-shaft & 250 Compressor | |
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Moto Guzzi 250 Racers
Moto Guzzi 250 Single-shaft 1930
After the success of the 500 four-valve, Moto Guzzi turned in
1925 to the construction of a Vt-liter two-wheeler with the same general
features as the 500, one that could also match the 500's racing achievements.
Thus was born the single-cylinder single-shaft 250. Because of the smaller
cylinder diameter, only two valves were installed.
The model that appeared in 1926 had 15 h.p., which was not exceptional for the
time. But, unlike other motorcycles, this one could generate that much power in
all kinds of operating conditions.
A few months after it first appeared in racing, the Guzzi 250
set several world records. Guzzi tried for world records with motorcycles that
had no special features but were adapted for Grand Prix racing. By 1935 the
Guzzi 250 had won countless races and was a kind of mobile testing ground for
the company's racing department. In 1927, fifty out of the sixty-two races won
by Guzzi were won by the 250 model. In 1930 the 250 won thirty-six of the
forty-nine victories the company had. Meanwhile the two-wheeler had undergone
changes. The chassis had been modified.
The transmission acquired another gear and was given pedal
control.
Moto Guzzi 250 Single-shaft, 1928-1929 model In 1935 Moto Guzzi gave a 250 and a
500 two-cylinder to the British racer Stanley Woods to drive at the difficult
Tourist Trophy. For that occasion the 250 was given a new rear suspension. It
was a very complicated elastic suspension system and also very heavy.
Nevertheless Woods outdistanced all the other motorcycles in the class. To win
the Tourist Trophy in those days meant admission to the elite of world racing.
That year Moto Guzzi won in the 250 class and the 500 class at the Tourist
Trophy, a truly memorable achievement.
Another feature of the 250 provided increased power. A fuel
mixture °f gas, alcohol, and benzol raised the motorcycle's power to 23 h.p. at
7,500 r.p.m. This vehicle could often offer better performance than the finest
racing 350s.
In 1937 the Guzzi people installed a Cozette supercharger,
which increased power to 38 h.p.
The Guzzi 250 with supercharger set a host of new world records. In 1939 it did
the flying kilometer at an average speed of 213 km./hr. (about 132 m.p.h.), a
record that the best 500s of the time barely managed to equal.
Motorcycle: Moto Guzzi 250 Single-shaft Manufacturer: Moto
Guzzi, Mandello del
Lario Type: Racing Year: 1930
Engine: Guzzi single-cylinder, horizontal, four-stroke, with overhead
single-shaft distribution and bevel gear shaft. Displacement 246.9 cc. (68 mm. x
68 mm.)
Cooling: Air
Transmission: Three-speed, hand controls Power: 20 h.p. at 6,800 r.p.m. Maximum
speed: About 87.5 m.p.h. Chassis: Continuous tubular double
cradle, rigid rear. Front, parallelogram
suspension Brakes: Front and rear, central drum
Moto Guzzi 250 Compressor 1938
Motorcycle manufacturers as diverse as Douglas, Garelli and
Victoria had produced supercharged motorcycles during the 1920s, but the first
blown Moto Guzzi was the Compressore of 1930. However, like many of the other
supercharging projects of the era, it didnt progress beyond the prototype
stage.
During the 1930s Excelsior, Rudge and Velocette also experimented
with forced induction, but it was BMW in particular that achieved considerable
competition success with its various supercharged racers. By the latter half of
the decade it was clear that to compete at the highest level it was necessary to
use supercharged engines, and so in 1937 Moto Guzzi created a single-cylinder
250 with a French Cozette compressor.
The Guzzi 250 Compressore debuted in 1938 and the great Nello
Pagani rode the bike to eleven victories at Monza, along with seven further race
wins that year at other circuits, and 16 more the following year.
The 250 Compressores engine was essentially the same as the
normally aspirated 250 Monoalberos but with a lowered compression ratio. It
produced 48hp at 7,500rpm, while top speed was around 112mph (180km/h), or over
137mph (220km/h) in post-war record-breaking specification with raised
compression (8.5:1) and sometimes running on alcohol. After over 20 years of
service Moto Guzzi ceased production of the 250 Compressore in 1959.