Function of the injection system: - ra07176020010x(0010)

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Q. Nozzle holder Engine 602.96, 603.96/97 TURBO (Model 463.3: pay attention to variations)

Q. Nozzle holder

Bosch Designation:

KCA 27 S 55, for oblique injection

KCA 30 S 44, for vertical injection

The thickness of the shim (40) determines the pre-load of the compression spring (36) and thus the opening pressure of the injection nozzle. The ejection pressure can be set by fitting shims of different thicknesses. The fuel flows to the nozzle seat through the respective inlet orifice (a) in the holder (37), intermediate disk (33) and injection nozzle. During the injection process, the injection pressure raises the nozzle needle, and fuel flows through the annular orifice at the throttling pintle into the prechamber. Once the injection pressure drops, the compression spring (36) pushes the nozzle needle (31) back down onto its seat; the injection process is completed.

Fig 1: Cross-Sectional View Of Nozzle Holder

Courtesy of MERCEDES-BENZ OF NORTH AMERICA.

Nozzle holder KCA 27 S 55 (for oblique injection)

Fig 2: Identifying Nozzle Holder Components

Courtesy of MERCEDES-BENZ OF NORTH AMERICA.