Series 55 – Section 1.2 Cylinder Head

Section 1.2
Cylinder Head

Each cylinder head uses intake and exhaust valve porting and water jacketing around the injector nozzle holder to cool the ports, injector nozzle, and combustion chamber area. See Figure "Cylinder Head Assembly and Related Parts" .‪

1.Exhaust Valve (2)‪	8.Valve Keepers‪
2.Valve Seat Insert‪	9.Valve Spring‪
3.Exhaust Porting‪	10.Valve Guide‪
4.Cylinder Head‪	11.Inlet Porting‪
5.Lower Valve Seat‪	12.Intake Valve (2)‪
6.Valve Stem Seal‪	13.Water Jacket‪
7.Upper Valve Seat‪	14.Injector Nozzle Tube‪

Figure 1. Cylinder Head Assembly and Related Parts

The cylinder head features cross-flow porting, with intake and exhaust ports on opposite sides. Two intake and two exhaust valves are used per cylinder. Replaceable valve guides, valve spring seats, valve stem seals, and valve seat inserts are used on all valves.‪

Section 1.2.1
Repair or Replacement of Cylinder Head

To determine if repair is possible or replacement is necessary, perform the following procedure. See Figure "Repair or Replacement of Cylinder Head Flowchart" .‪

Figure 2. Repair or Replacement of Cylinder Head Flowchart

Section 1.2.2
Removal of Cylinder Head

Because optional and accessory equipment varies with the engine application, this procedure covers only the basic engine. If the engine is equipped with accessories that affect cylinder head removal, note the mounting details of each to assure correct installation at reassembly.‪

Remove the cylinder head as follows:‪

1. Drain the cooling system. Refer to "13.4.4 Cooling System" .
2. Drain the engine lubricating system. Refer to "13.4.1 Lubricating Oil" .
3. Disconnect the exhaust pipe at the turbocharger. Refer to OEM guidelines.
4. Disconnect the air and hydraulic lines from the engine brake.
5. Remove the air cleaner and CAC ducting from the turbocharger and the intake manifold. Refer to OEM guidelines.
6. Disconnect the turbocharger oil supply and drain lines. See Figure "Turbocharger and Oil Line Removal and Installation" . Remove the turbocharger, if necessary. Refer to "6.4.2 Removal of Turbocharger" .
   

   1.Oil Drain Line‪	6.Fitting‪
   2.Bolt‪	7.Oil Supply Line‪
   3.Gasket‪	8.Mounting Studs‪
   4.Turbocharger Assembly‪	9.Gasket‪
   5.Nut‪	10.Elbow Fitting‪

   Figure 3. Turbocharger and Oil Line Removal and Installation

7. Seal the turbocharger compressor inlet and discharge with covers or masking tape. Plug the oil supply fitting in the turbocharger housing.
8. Remove and inspect the exhaust manifold. Refer to "7.2.2 Removal of Exhaust Manifold" .
9. Remove coolant vent tube assembly.
10. Remove engine brake lines (air or oil). See Figure "Removal of Exhaust Assembly" .
    

    1.Exhaust Manifold‪	7.Retainer Clip‪
    2.Spacer‪	8.Copper Seal‪
    3.Bolt‪	9.Copper Washers‪
    4.Gasket‪	10.Banjo Bolt‪
    5.Spacer‪	11.Coolant Vent Lines‪
    6.Banjo Bolt‪	12.Engine Brake Lines‪

    Figure 4. Removal of Exhaust Assembly

11. Remove turbo boost connector and the air temperature sensor connector. See Figure "Air Inlet and Related Parts" and refer to "2.12.2 Removal of Turbo Boost Sensor" .
12. Disconnect the air compressor lines to the intake manifold. Refer to "10.1.2 Cleaning and Removal of Air Compressor" .
13. Remove the air inlet elbow and clamp. See Figure "Air Inlet and Related Parts" .
14. Remove intake manifold bolts and intake manifold. Refer to "6.3.2 Removal of Intake Manifold"
    

    1.Elbow‪	4.Air Temperature Sensor Connector‪
    2.Clamp‪	5.Intake Manifold‪
    3.Bolt‪	6.Turbo Boost Sensor Connector‪

    Figure 5. Air Inlet and Related Parts

15. Remove intake manifold gaskets from cylinder heads or intake manifold.
16. Remove the high pressure fuel line from each head and electronic unit pump. See Figure "Intake Manifold, Gaskets, Coolant Vent Line, and High Pressure Fuel Line Removal" .
    

    1.Intake Manifold‪	7.Fuel Return Line‪
    2.Bolt‪	8.High Pressure Fuel Line‪
    3.Gasket‪	9.Fuel Pressure Regulator Valve‪
    4.Copper Seal‪	10.Fuel Galley Return Outlet‪
    5.Banjo Bolt‪	11.Copper Seals‪
    6.Copper Seal‪	12.Banjo Bolt‪

    Figure 6. Intake Manifold, Gaskets, Coolant Vent Line, and High Pressure Fuel Line Removal

17. Remove each valve rocker cover. Refer to "1.3.2 Removal of Rocker Cover" .
18. Remove the rocker shaft assemblies. See Figure "Removal of Rocker Cover, Gasket and Rocker Arm Shaft Post" .
19. Remove all push rods. See Figure "Removal of Rocker Cover, Gasket and Rocker Arm Shaft Post" .
    

    1.Cylinder Head‪	7.Rocker Arm Post Bolt‪
    2.Valve Bridge‪	8.Push Rod‪
    3.Rocker Arm Shaft Assembly‪	9.Rocker Arm‪
    4.Gasket‪	10.Spacer‪
    5.Rocker Cover‪	11.Snap Ring‪
    6.Rocker Cover Bolt‪	‪

    Figure 7. Removal of Rocker Cover, Gasket and Rocker Arm Shaft Post

20. Remove the cylinder head bolts. See Figure "Cylinder Head and Gasket Removal" .
21. Remove the cylinder head and gasket. See Figure "Cylinder Head and Gasket Removal" .
    

    1.Cylinder Block‪	3.Cylinder Head Mounting Bolt‪
    2.Cylinder Head‪	4.Cylinder Head Gasket‪

    Figure 8. Cylinder Head and Gasket Removal

Section 1.2.3
Disassembly of Cylinder Head

Disassemble the cylinder head as follows:‪

Note: Use J-41587 when removing either the air or hydraulic engine brake.

1. Remove engine brake exhaust valve. Refer to "1.22.1 Removal of Engine Brake" .
2. Remove the internal fuel line. See Figure "Removal of Internal Fuel Line, Injector Nozzle Holder, and Injector Nozzle" .
3. Remove the injector nozzle and seal rings usingJ 41570 ; slide hammer. See Figure "Removal of Internal Fuel Line, Injector Nozzle Holder, and Injector Nozzle" .
4. Remove valves. Refer to "1.4.2 Cleaning and Removal of Valve Spring" .
   

   1.Nozzle Holder Assembly‪	4.Cylinder Head‪
   2.Cylinder Head O-ring‪	5.Internal Injection Line‪
   3.Copper Seal‪	6.Retaining Nut‪

   Figure 9. Removal of Internal Fuel Line, Injector Nozzle Holder, and Injector Nozzle

Section 1.2.4
Cleaning of Cylinder Head

Clean the cylinder head as follows:‪

1. If parts are to be reused, keep them segregated according to original position to assure proper reassembly.
2. Remove all threaded plugs.
3. Steam clean the cylinder head.
4. If coolant passages are heavily coated with scale, remove the cup plugs, and clean the head in a descaling bath.

Section 1.2.4.1
Inspection of Cylinder Head

Before inspecting the cylinder head, install new cup plugs, using a good grade non-hardening sealant, such as Loctite 620.‪

Perform the following cylinder head tests:‪

1. Perform pressure test. Refer to "1.2.4.2 Pressure Test of Cylinder Head" .
2. Perform the firedeck straightness test. Refer to "1.2.4.3 Inspection of Firedeck Flatness" .

Section 1.2.4.2
Pressure Test of Cylinder Head

Perform the pressure test as follows:‪

1. InstallJ 41567 to the cylinder head firedeck.
2. Insert the cylinder head bolts through the cylinder head. Attach and tighten the bolts (supplied in the kit) to 180 - 190 N · m (133 - 140 lb · ft).
3. Install dummy nozzle plug and a dummy injector shaft to seal the fuel injector path. See Figure "Cylinder Head Pressure Test Kit Installation" .
   

   Figure 10. Cylinder Head Pressure Test Kit Installation

   To avoid injury from flying debris when using compressed air, wear adequate eye protection (face shield or safety goggles) and do not exceed 40 psi (276 kPa) air pressure.‪

4. Apply 138 kPa (20 lb/in.2) air pressure to the cylinder head, and immerse the head in a water bath heated to 82-93 ° C (180-200 ° F).
5. Leave the head in the bath for at least 20 minutes to heat thoroughly, while watching for bubbles indicating a crack or leak. Replace any defective heads. Refer to "1.2.6 Installation of Cylinder Head" .

Section 1.2.4.3
Inspection of Firedeck Flatness

The head casting may be longitudinally warped after it is unbolted and removed from the engine block. When manufactured, longitudinal warp is normalized by fixturing and clamping the casting during machining. When unclamped, the head casting resumes its original shape until it is bolted and tightened to the engine block.‪

Inspect the bottom (firedeck) of each cylinder head for flatness as follows:‪

1. Use a heavy gage straightedge and feeler gages to check for transverse and longitudinal warpage.
2. Check for longitudinal warpage and transverse warpage. See Figure "Checking Firedeck Flatness" .
   

   1.Feeler Gage‪

   2.Straightedge‪

   Figure 11. Checking Firedeck Flatness

3. The natural warp of the casting must be considered when inspecting firedeck straightness. Natural warpage does not require correction. The firedeck (unclamped) must be flat with 0.015 mm (.0006 in.) front-to-rear and side-to-side

If the cylinder head warpage exceeds specifications listed in Table "Table Cylinder Head Specification for Warpage" , the head should be replaced.‪

Cylinder head check ‪	Specification ‪
Font-to-rear‪	0.015 mm (.0006 in.)‪
Side-to-side‪	0.015 mm (.0006 in.)‪

Section 1.2.5
Assembly of Cylinder Head

Assemble the cylinder head as follows:‪

To avoid injury from flying debris when using compressed air, wear adequate eye protection (face shield or safety goggles) and do not exceed 40 psi (276 kPa) air pressure.‪

NOTICE:
Whenever a cylinder head is replaced, the new head must be thoroughly cleaned to remove all rust preventive compound. Immerse the head in a bath of fuel oil or mineral-spirits-based solvent, and scrub out all openings with a soft-bristle brush. Dry the head with compressed air.‪

1. Using a good grade of non-hardening sealant, such as Loctite 620, install all required cup plugs. Use cup plug installation tool J 41746 .
2. Ensure all cup and pipe plugs on the front face of the cylinder head are flush or below the surface.
3. Install valves. Refer to "1.4.5 Installation of Valve" .
4. Install the engine brake. Refer to "1.22.2 Installation of Engine Brake" .
5. Install nozzle holder assembly hold down bracket with M10 screw. Torque to 58-73 N · m (43-54 lb · ft). See Figure "Injector Nozzle Assembly" .
6. Install high pressure tube. See Figure "Injector Nozzle Assembly" .
7. Install hollow nut. Torque to 35 N · m (26 lb · ft). See Figure "Injector Nozzle Assembly" .
   

   1.Injector Nozzle Hold Down Crab‪	5.Copper Seal‪
   2.Bolt‪	6.Cylinder Head‪
   3.Nozzle Holder Assembly‪	7.Internal Injection Line‪
   4.Cylinder Head O-ring‪	8.Retaining Nut‪

   Figure 12. Injector Nozzle Assembly

8. Install injection line. Torque both nuts to 27 N · m (20 lb · ft).

Section 1.2.6
Installation of Cylinder Head

Install the cylinder head as follows:‪

1. Ensure piston domes and the cylinder head and cylinder block firedecks are clean. Inspect the head bolt holes in both the block and the head for oil, water, dirt, or damaged threads. Clean or retap, as necessary.
2. Align the new head gasket with cylinder head dowels, and install new head gasket.
3. Install new cylinder head. See Figure "Cylinder Head Installation" .
   

   1.Cylinder Block‪	3.Cylinder Head Mounting Bolt‪
   2.Cylinder Head‪	4.Cylinder Head Gasket‪

   Figure 13. Cylinder Head Installation

   1. Apply International Compound #2 to cylinder head Mounting bolts. See Figure "Cylinder Head Mounting Bolt Length Dimension" .
   

   Figure 14. Cylinder Head Mounting Bolt Length Dimension

   2. If bolts are not within specification, discard.
4. Tighten head bolts to the torque specification listed in Table "Cylinder Head Torque Specifications" , in a criss-cross pattern.

   Description ‪	Specification ‪
   First step‪	10 N · m (7 lb · ft)‪
   Second step‪	50 N · m (37 lb · ft)‪
   Third step‪	100 N · m (74 lb · ft)‪
   Fourth step‪	140 N · m (103 lb · ft)‪
   Fifth step‪	180 - 190 N · m (133 - 140 lb · ft)‪
   Sixth step‪	Turn torque an additional 180 °‪

   Table 16. Cylinder Head Torque Specifications
5. Repeat the torque sequence for remaining cylinder heads.
6. Insert push rods.
7. Install each valve bridge and rocker arm and shaft assemblies. See Figure "Rocker Arm and Rocker Cover Assembly" .
8. Torque post bolts to 57-61 N · m (42-45 lb · ft).
9. Adjust valve lash. Refer to "12.2 Adjustments of Valve Lash" .
10. Place new gasket onto the rocker cover. See Figure "Rocker Arm and Rocker Cover Assembly" .
    

    1.Cylinder Head‪	7.Rocker Arm Post Bolt‪
    2.Valve Bridge‪	8.Push Rod‪
    3.Rocker Arm Shaft Assembly‪	9.Rocker Arm‪
    4.Gasket‪	10.Spacer‪
    5.Rocker Cover‪	11.Snap Ring‪
    6.Rocker Cover Bolt‪	‪

    Figure 15. Rocker Arm and Rocker Cover Assembly

11. Install high pressure fuel line. See Figure "Intake Manifold, Fuel Return Line, and High Pressure Fuel Line" .
12. Install engine brake lines. See Figure "Exhaust Manifold and Coolant Vent Line Installation" .
13. Install fuel return line and deaeration line. See Figure "Intake Manifold, Fuel Return Line, and High Pressure Fuel Line" .
14. Install intake manifold and gasket. Refer to "6.3.3 Installation of Intake Manifold" .
    

    1.Intake Manifold‪	7.Fuel Return Line‪
    2.Bolt‪	8.High Pressure Fuel Line‪
    3.Gasket‪	9.Fuel Pressure Regulator Valve‪
    4.Copper Seal‪	10.Fuel Galley Return Outlet‪
    5.Banjo Bolt‪	11.Copper Seals‪
    6.Copper Seal‪	12.Banjo Bolt‪

    Figure 16. Intake Manifold, Fuel Return Line, and High Pressure Fuel Line

15. Install fuel return line. See Figure "Intake Manifold, Fuel Return Line, and High Pressure Fuel Line" .
16. Install air inlet elbow and clamp. See Figure "Air Inlet Elbow and Manifold Sensor Connectors" .
17. Install the turbo boost and air intake sensor connectors. Refer to "2.12.3 Installation of Turbo Boost Sensor" .
    

    1.Elbow‪	4.Air Temperature Sensor Connector‪
    2.Clamp‪	5.Intake Manifold‪
    3.Bolt‪	6.Turbo Boost Sensor Connector‪

    Figure 17. Air Inlet Elbow and Manifold Sensor Connectors

18. Install exhaust manifold, gasket, and coolant vent line. Refer to "7.2.3 Installation of Exhaust Manifold" .
    

    1.Exhaust Manifold‪	7.Retaining Clip‪
    2.Spacer‪	8.Copper Seal‪
    3.Bolt‪	9.Copper Washers‪
    4.Gasket‪	10.Banjo Bolt‪
    5.Spacer‪	11.Coolant Vent Lines‪
    6.Banjo Bolt‪	12.Engine Brake Lines‪

    Figure 18. Exhaust Manifold and Coolant Vent Line Installation

19. Install turbocharger and turbocharger oil lines. Refer to "6.4.3 Installation of Turbocharger" .
20. With the engine running, check for fuel, coolant, or oil leaks.