QSB4.5 and QSB6.7 Engine Identification Section E - Engine and System Identification Page E-7 Air Compressor NOTE: Not all engines are equipped with an air compressor. The Cummins® branded air compressor dataplate, identified by the Cummins Inc. logo, is typically located on the side of the air compressor. The dataplate contains the following information to assist in servicing or replacement: Cummins® part number Serial number Date code.