1946 Nougier 250 Tournevis
Jean Nougier was a brilliant
craftsman-mechanic who - from 1937 to his last French motorcycling championship
in 1972 - either starting with proprietary components or working from the raw
metal, hand-built the racing motorcycles that were sadly lacking from the
output of the French manufacturers. Designed in 1939 and 1940, the Tournevis
("Screwdriver") was highly successful. Recalled Nougier: "Ridden by my brother
Henri or by de Shaad, it won at least 40 races, including the 1946 Avignon
Grand Prix. The following year, it finished second at Avignon behind the works
Guzzi ridden by Fergus Anderson."
All His Own Work
Entirely
hand-built, the engine was a superb double overhead camshaft unit topped by
impressive hairpin valve springs. This type of spring long remained popular on
racing engines since - at a time when the steels of the period often broke - it
was easily replaceable without dismantling the engine, unlike a conventional
coil spring.
Maximum Power at 10,000rpm
The Tournevis took its name
from the method of driving the overhead camshaft by a vertical shaft with a
blade and slot coupling. "At first," said Nougier, "I had this long-stroke
engine running at 9000rpm; by the end of its racing career it was touching
10,000rpm." The crankshaft ran in three bearings and the separate gearbox was a
modified Terrot unit. As for the rear suspension - a rarity at the time - it
was also "home-brewed", with a forward-mounted brake to avoid kick-back at the
pedal.