By Pete Vack
From the VeloceToday Archives, July, 2010
For the 1923 French GP, French car builder Gabriel Voisin and his ‘spiritual son’ André Lefebvre, entered four highly advanced race cars equipped with a 2 liter six cylinder Knight sleeve valve engine, which was a mainstay of his fabulous line of luxury cars. But what is a sleeve valve engine, who was Knight and why did Voisin choose such a layout, straight from the American heartland?