The Allouchéry 5 cc “Vitesse” (Speed) racing engine was a somewhat ephemeral product of the Allouchéry model engine manufacturing venture in Paris, France. Founded by Prosper Allouchéry, the company operated from 1943 through to 1960, subsequently being briefly revived between 1965 and 1967 by the founder's brother and nephew.
The Allouchéry 5 cc “Vitesse” (Speed) racing engine made its one and only appearance in the French modelling media in 1966, seemingly making it a product of the revived company. However, its design does not reflect a mid-1960's date, being entirely characteristic of early 1950's design thinking. It seems likely that it was actually designed and a small batch of components made back then by the original maker but was set aside for whatever reason, to be revived in the mid-1960's on the basis of components already on hand. Whatever the truth, very few examples appear to have been produced. Given the engine's then-uncompetitive design, it was probably aimed at the nostalgia market whch was then beginning to open up.
A full analysis and test of this very rare engine appears elsewhere on this website, together with a capsule history of the Allouchéry range.