FRAME A ENG 3V5940 - Caterpillar

Cylinder Heads That Can Be Modified
Table 1 lists the part numbers for the cylinder head groups that can be modified. These groups contain a 170-5077 Cylinder Head. The part number for the head is cast into the passage for the intake air.
Table 1
Cylinder Head Groups That Can be Modified    
Application    Part Number for the Cylinder Head Group    
9:1 compression ratio     171-3994    
213-6962
219-2955
10.5:1 compression ratio     219-2956    
213-6964
Bio-gas fuel     219-2957    
213-6966 Note: Modifying these cylinder heads does not change the core credit status of the cylinder heads. However, core credit for the cylinder head may be denied if the cylinder head is improperly modified or if the cylinder head is damaged during the modification.Modify the Cylinder Head and the Prechamber Assembly
Note: Modifications to a cylinder head must be performed by a qualified Caterpillar dealer technician.Note: The cylinder head must be removed from the engine before the cylinder head is modified. If the cylinder head remains on the engine during the modification, metal chips may contaminate the cylinder head or other engine components. Severe engine damage may result.
Remove the cylinder head from the engine.
Remove the prechamber assembly from the cylinder head.
Illustration 1 g01001377
Specifications for modifying the cylinder head
Modify the cylinder head according to the specifications in Illustration 1. Proper alignment of the drill bits and the tap drill is required in order to obtain the correct dimensions. A magnetic drill fixture or a drill press must be used in order to properly machine the cylinder head to the new dimensions.
Illustration 2 g01001384
Top view of the flange on the prechamber assembly
After you secure the prechamber assembly in an appropriate fixture, modify the prechamber assembly according to the specifications in Illustration 2.Clean the Gasket Surfaces
Note: Failure to provide gasket surfaces that are clean and free of defects may result in coolant leaks into the combustion chamber.Always inspect all of the gasket surfaces on the cylinder head and on the prechamber assembly prior to reassembly of the components. Ensure that the surfaces are free of debris and of defects.Clean the gasket surfaces on the prechamber assembly by using one of these tool groups:
9U-5156 Cleaning Tool Gp
187-6273 Machining Tool Gp Note: The 187-6273 Machining Tool Gp may require modifications to the cutting head prior to use. Contact your local Caterpillar dealer for additional information.After the gasket surfaces have been cleaned, perform a final cleaning. Use a towel that has been soaked with a component cleaner that does not leave any residue. The 138-8440 Component Cleaner is acceptable for such use.New Hardware Requirements
Table 2 lists the new hardware that is required for each cylinder that has been modified.
Table 2
New Hardware Requirements    
Quantity    Part Number    Description of the Part    
2     8D-0648     Bolt    
2     5P-8245     Hard Washer    
2     5V-7652     Spacer    Note: Always use a new gasket assembly for the prechamber assembly after performing any service that requires removal