Source text: Georgano, G. The complete encyclopedia of motorcars: 1885 to present, second edition, London, Ebury Press, 1973.
Source picture: Patented Systems
[Classication = Group 3(1)]
Pictures of the Bignan Desmo. These cars were known for their square radiator with a winged stork on top, which could be vaguely seen in the picture. This is a 1923 Bignan 11Cv DESMO Sports. The engine is a 2L single OHC with Desmodromique valves. The picture was taken in 1925 during the ‘Côte des 17 tournants’ (a hill climb near Dampierre in the Chevreuse Valley).
(photos collection Karl Ludvigsen Library and collection Pascal Rousselle) Source: http://www.prewarcar.com/news-home/page-33-4444444444.html
The Bignan is classified as a Group 3 (1) system, which means a “positive” cam with a “negative” camfollower
The perspex model is classified as a Group 3 (2) system, which means a “negative” cam (groove) and positive camfollower