A fluid rail for conveying an actuating fluid under pressure from an actuating fluid source to a respective fuel injector of an internal combustion engine includes a rail assembly being disposable in a space defined in part by a rocker arm carrier of the engine and having; a. a first rail portion having a substantially cylindrical inside diameter defining a first substantially cylindrical flow passage; b. a second rail portion having a substantially cylindrical inside diameter defining a second substantially cylindrical flow passage; c. having a volume of between 15 cubic inches and 60 cubic inches. A method of conveying an actuating fluid under pressure from an actuating fluid source to a respective fuel injector of an internal combustion engine is further included.