Grand Prix moto des Pays-Bas
For the 1952 Dutch TT, Amm was a full member of the Norton team and was second to Geoff Duke in the 350cc Dutch TT and retired from the 500 cc race. At the 1952 German Grand Prix held at Solitude, Amm crashed and broke a leg, returning later in the 1952 Grand Prix motorcycle racing season to win the 350 cc class for the 1952 Nations Grand Prix held at Monza in Italy.