Abstract: A method for the pilot injection of fuel in a direct injection diesel engine with a depression in the tops of the pistons. The pilot fuel, of relatively high cetane number, e.g. diesel fuel, is sprayed prior to the main spray, obliquely from the side into the piston depression in a direction counter to the rotation of the intake air. Thereafter, during the same combustion cycle, the main spray, of lower cetane number, e.g. methanol, is sprayed in a zone around the center axis of the piston depression. A substantial reduction in pollutants is achieved.

Abstract: A fuel injection system for direct injection diesel engines with a depression in the tops of the pistons. A first injection pump has a regulator and accompanying first injector for each cylinder, the injectors being disposed to spray the fuel in a zone around the center axis of the respective piston depression. A second injection pump has a regulator and accompanying second injector for each cylinder, the second injectors being disposed to inject fuel obliquely from the side into the respective piston depression in a direction counter to the rotation of the intake air before the fuel from the first injectors is injected.