Injection nozzle for a combustion engine

The injection nozzle has an inner contour with a pre-chamber (14) that opens at an end into a spray chamber with an inlet opening (13). A cylindrical guide channel (17) that is connected to another end of the pre-chamber communicates with outside of a body through an outlet opening (18). The diameter or cross-section of the inlet opening of the pre-chamber is 50 percent larger than the guide channel. The pre-chamber comprises a constriction (16) with a narrowing section (15). The ratio of length of the guide channel to length of the pre-chamber lies in a range of 1 is to 0.2 to 1 is to 0.8.