Fuel injection assembly with optimised heat coupling between fuel injection device and cylinder head

The arrangement (1) has an injection device i.e. fuel injector (2), for injecting fuel i.e. diesel, into a combustion chamber (3) of an internal-combustion engine. The injection device is arranged in a cylinder head (6) of the engine. A gap (4) is formed between the injection device and the cylinder head and/or mounted part i.e. cylinder head cover (10). The gap is completely filled with heat conducting liquid (7) e.g. oil, with heat conductivity greater than air or an elastically-deformable heat conducting component e.g. casing, with heat conductivity greater than the air.