The highly individualistic twin-stack .15 cuin. (2.5 cc) glow-plug models which formed part of the Fuji series were among the many individualistic designs produced under the Fuji trade-name during the first 15 years of the marque's existence. The initial Fuji offering in this displacement category appeared in early 1955.  It was actually the first commercially-marketed Japanese engine meeting the FAI’s 2.5 cc displacement limit for international competition from 1955 onwards, although it was soon followed by others. A detailed article about the Fuji .15 twin-stack models, including bench tests of a number of variants, may be found elsewhere on this website.