F02B 69/04

Internal-combustion engines convertible into other combustion-engine type, not provided for in [CPC: F02B11/00]; Internal-combustion engines of different types characterised by constructions facilitating use of same main engine-parts in different types for different fuel types, other than engines indifferent to fuel consumed, e.g. convertible from light to heavy fuel for gaseous and non-gaseous fuels