The Vltavan racing engines from Czechoslovakia (now Czechia) were produced in Prague during the late 1950's as "consumer-grade" racing engines which could be used by aspiring Czech competitors to gain the experience necessary to potentially compete at the international level. They were essentially copies of the individually-produced tool-room specials constructed by the MVVS workshops at Brno for the use of the official Czech teams at major events. Production was confined to the years 1957 - 1960. 

The engines were quite well made, also performing at quite competitive levels by the commercial standards of their day, albeit not at the level of their MVVS progenitors. They probably served their intended purpose very well. Their manufacture was only terminated when a decision was taken to increase production levels at the MVVS workshops, thus making those engines more readily available. 

The full stories of the Vltavan 2.5 cc and Vltavan 5 cc models may be found elsewhere on this website. There's also a review of the very interesting Vltavan Twin which was constructed by combining two single-cylinder Vltavan 5 engines to create a 10 cc in-line alternate-firing glow-plug model.