Assembly of a common rail in an internal combustion engine

An assembly of a common rail in an internal combustion engine comprises a common rail (12, fig.1) having an elongate tubular body 20 extending along a longitudinal axis (22, fig.2) with an inner longitudinal bore 23 for containing pressurized fuel. The body 20 includes a plurality of transversally protruding connecting pieces 28, each connecting piece comprising a branch bore 30 in communication with the longitudinal bore. Two or more mounting supports 16 are provided as parts of engine component(s) of the internal combustion engine, for assembling the common rail (12) to the engine. The mounting supports 16 include a through hole 18. At least two of the connecting pieces 282 (and 284, fig.2) are also referred to as carrier pieces, and perform an additional mounting function, and are engaged in the holes 18 of the mounting supports, respectively, and are locked therein by a respective locking elements 50.