INTERNAL COMBUSTION ENGINE

An internal combustion engine 20 includes a combustion chamber 26, a fuel injector 31 injecting fuel into the combustion chamber 26, a cylinder 22, a piston 24 having a crown and reciprocating in the cylinder 22, the crown being exposed to the combustion chamber 26, and an ignition delay enhancer prolonging an ignition delay of a fuel-air mixture in the combustion chamber 26. A ceramic member 24a is disposed on at least a fuel injection port, to which fuel is injected from the fuel injector 31, of the crown of the piston 24.