Sylinterinkansi

An internal combustion engine of the known type has a 4-valve cylinder head with a central injector valve. To cool the cylinder head floor, coolant flows via a total of eight inlets into individual outer cooling chambers in the cylinder head before passing via cast channels into an inner cooling chamber surrounding the injector valve. From there, the coolant passes directly to an outlet. This internal combustion engine is improved by the feature that a cooling chamber between the cylinder head floor (25) and an intermediate partition (17) includes an outter uninterrupted annular chamber (12) which is connected via straight cooling bores (13) with an injector valve cooling chamber (14) in the middle of the cylinder head floor (25), and by the presence of additional cooling channels (19) which connect at least one outlet valve cooling chamber (20) with the annular chamber (12) and injector valve cooling chamber (14). This design facilitates effective cooling of the cylinder head in those areas subjected to thermal stress and is also advantageous in structural terms. In addition, the assembly process entailed by the invention is optimised by the fact that cylinder head, intermediate housing, cylinder pipe, piston and connecting rod form a single assembly unit which can be pre-assembled. These components can thus be assembled at one site by mechanics especially trained for that task and then fitted as a pre-assembled unit in the engine.