The Allbon Bambi diesel was the smallest-displacement model engine every to enter series production. At 0.15 cc (0.009 cui.), it was even smaller than the Cox Tee-Dee 010 which has often been accorded the honor of the "world's smallest". There have been smaller engines, notably the astonishing miniatures which are individually made by Ronald Valentine, but these cannot truly be said to be series production models.
The Bambi was actually manufactured by Davies-Charlton (D-C) Ltd. of Barnoldwick in Lancashire. The name Allbon was attached to it in recognition of the fact that it was actually designed by Alan Allbon during the period when he worked for D-C Ltd. in Barnoldswick.
The Bambi represented a significant production challenge, which was reflected in its relatively high price. According to a story which leaked out of the factory, examples which failed their test runs for any reason (and there were apparently a few) were simply thrown into the rubbish bin because it was too costly to fix them! However, the majority of examples which were actually sold ran well and were far less difficult to start than their later reputation might suggest. Power was adequate to fly a small free flight model quite effectively.
The full story of the Allbon Bambi may be found in an article on Ron Chernich's "Model Engine News" (MEN) web-site.