A combustion cylinder assembly for an internal combustion engine, the combustion cylinder assembly comprising: a combustion cylinder; a glow plug projecting into the combustion cylinder; a piston movable reciprocally within the combustion cylinder; and a fuel injector configured to inject fuel vapour into the combustion cylinder of the internal combustion engine, the fuel injector comprising: an injector body having a central axis and being mountable to the internal combustion engine such that the fuel injector projects into the combustion chamber; an inlet for supplying fuel to the fuel injector, the inlet projecting from the injector body at a first circumferential position of the injector body and having a component of projection, X, radially outward relative to the central axis; a spray nozzle having a tip, the spray nozzle extending longitudinally from the injector body; and a plurality of spray discharge orifices formed on the tip having an even radial distribution about the tip, each spray discharge orifice configured to discharge fuel vapour; characterized in that each spray discharge orifice has a component of direction parallel to the central axis and a component of direction, Y, radially outward relative to the central axis; wherein the glow plug is aligned with axis X; and wherein Y is at an angle offset from X. a combustion cylinder; a glow plug projecting into the combustion cylinder; a piston movable reciprocally within the combustion cylinder; and a fuel injector configured to inject fuel vapour into the combustion cylinder of the internal combustion engine, the fuel injector comprising: an injector body having a central axis and being mountable to the internal combustion engine such that the fuel injector projects into the combustion chamber; an inlet for supplying fuel to the fuel injector, the inlet projecting from the injector body at a first circumferential position of the injector body and having a component of projection, X, radially outward relative to the central axis; a spray nozzle having a tip, the spray nozzle extending longitudinally from the injector body; and a plurality of spray discharge orifices formed on the tip having an even radial distribution about the tip, each spray discharge orifice configured to discharge fuel vapour; characterized in that each spray discharge orifice has a component of direction parallel to the central axis and a component of direction, Y, radially outward relative to the central axis; wherein the glow plug is aligned with axis X; and wherein Y is at an angle offset from X. an injector body having a central axis and being mountable to the internal combustion engine such that the fuel injector projects into the combustion chamber; an inlet for supplying fuel to the fuel injector, the inlet projecting from the injector body at a first circumferential position of the injector body and having a component of projection, X, radially outward relative to the central axis; a spray nozzle having a tip, the spray nozzle extending longitudinally from the injector body; and a plurality of spray discharge orifices formed on the tip having an even radial distribution about the tip, each spray discharge orifice configured to discharge fuel vapour; characterized in that each spray discharge orifice has a component of direction parallel to the central axis and a component of direction, Y, radially outward relative to the central axis; wherein the glow plug is aligned with axis X; and wherein Y is at an angle offset from X.