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SERIES 638 CYLINDER BLOCK

The cylinder block is the basic engine structure, establishing and maintaining the alignment of all engine working parts. In the Turbotronic 638 engine, the cylinder bores are not an integral part of the block casting, but are in the form of replaceable, wet type cylinder liners. ‪

Cooling of the cylinder block is accomplished by the water pump located in the front of the cylinder block which is belt driven. Coolant flows inside the cylinder block around the cylinder liners and through internal passages and rises to the cylinder head. The water manifold collects the coolant at the cylinder head outlets and diverts the coolant flow to the water pump or to the radiator where the coolant temperature is reduced. ‪

Lubricating oil is circulated through the cylinder block by a rotor type oil pump located in the front of the cylinder block and driven by a gear directly meshing with the crankshaft gear. ‪

Oil is directed through an oil pressure relief valve to the full-flow oil filter and through appropriate oil passages machined in the cylinder block to the main bearing carriers, camshaft bearings, and the turbocharger. Oil jets located on the main bearing carriers lubricate and cool: piston pins, and internal areas of the pistons. ‪

External oil lines allow proper lubrication of the rocker arms and hydraulic lifters. A bypass valve located in the oil filter cartridge allows oil circulation even if the filter is clogged. ‪

Repair or Replacement of Cylinder Block

To determine if replacement of the cylinder block is necessary, perform the following procedure. See Figure 28398 . ‪

Flowchart of Cylinder Block Repair or Replacement

Removal of Engine Assembly

Perform the following to separate the engine from the transmission: ‪

  1. Disconnect the battery cable(s) from the battery.
  2. Drain the cooling system. Refer to section .
  3. Drain the lubricating oil. Refer to section .
  4. Disconnect the inlet fuel line from the fuel filter and the outlet line from the fuel filter to the transfer pump.
  5. Remove air cleaner ducting, as necessary.
  6. Remove intercooler ducting from the turbocharger and intake manifold.
  7. Disconnect the exhaust piping from the turbocharger.
  8. Disconnect the Electronic Control Unit (ECU) wire harness from the engine injector pump and sensors.
  9. Disconnect and remove the starter motor, alternator, and other electrical equipment, as necessary.
  10. Disconnect and remove coolant hoses.
  11. Remove the radiator, fan guard, and other related cooling system parts, as necessary.
  12. Disconnect the engine from the transmission. Refer to OEM guidelines.
  13. Remove the engine mounting bolts.

    To avoid personal injury and damage to the engine, a spreader bar should be used with a sling and adequate chain hoist when lifting any engine. The lifting device should be adjusted so the lifting hooks are vertical to prevent bending the engine lift brackets. To ensure proper weight distribution, all engine lift brackets provided must be used in lifting the engine. Be sure the spreader bar is adequate to prevent lifter brackets from contacting the rocker cover, which may damage the rocker cover. Never lift an engine by any other means.

  14. Connect a suitable lifting device to the engine and separate the engine from the transmission.

    Make certain the engine is securely attached to the engine overhaul stand before releasing the lifting sling. Severe injury and engine damage may result if the engine breaks away from the stand. ‪

  15. Mount the engine to a suitable engine stand for support when performing a tear-down.

Perform the following to disassemble the cylinder block: ‪

  1. Disconnect and remove any electrical components, connectors, or wiring harnesses from the engine.
  2. Remove transfer pump. Refer to section .
  3. Remove the crankshaft vibration damper. Refer to section .
  4. Remove the crankshaft pulley. Refer to section .
  5. Remove the front cover. Refer to section .
  6. Remove injector pump. Refer to section .
  7. Remove the flywheel. Refer to section .
  8. Remove the flywheel housing. Refer to section .
  9. Remove the turbocharger. Refer to section .
  10. Remove oil filter adaptor. Refer to section .
  11. Remove water pump. Refer to section .
  12. Remove the water manifold. Refer to section .
  13. Remove intake manifold. Refer to section .
  14. Remove exhaust manifold. Refer to section .
  15. Remove the rocker covers. Refer to section and refer to section .
  16. Remove cylinder heads. Refer to section .
  17. Remove the rear main bearing carrier assembly. Refer to section .
  18. Remove the oil pan. Refer to section .
  19. Remove the vacuum pump. Refer to section .
  20. Remove the oil pump. Refer to section .
  21. Remove the oil pickup tube. Refer to section .
  22. Remove the piston and rod assemblies. Refer to section .
  23. Remove the crankshaft. Refer to section .
  24. Remove the cylinder liners. Refer to section .
Cleaning of Cylinder Block

Perform the following to clean the cylinder block: ‪

  1. Remove all cup plugs and plugs to allow the cleaning solution to enter the inside of the oil and water passages.
  2. Remove all Loctite material and residue around the cylinder bores.
  3. Immerse and agitate the block in a hot bath of a commercial, heavy-duty alkaline solution.
  4. Wash the block in hot water or steam clean it to remove the alkaline solution.
  5. If the water jackets are heavily scaled, proceed as follows:
    1. Agitate the block in a bath of inhibited phosphoric acid.
    2. Allow the block to remain in the acid bath until the bubbling action stops (approximately 30 minutes).
    3. Lift the block, drain it and re-immerse it in the same acid solution for 10 more minutes. Repeat until all scale is removed from the water jacket area.
    4. Rinse the block in clear, hot water to remove the acid solution.
    5. Neutralize the acid that may cling to the casting by immersing the block in an alkaline bath.
    6. Wash the block in clean water or steam clean it.
    7. To avoid personal injury when blow drying, wear adequate eye protection (safety glasses or face plate) and do not exceed 276 kPa (40 lb/in. 2 ) air pressure. ‪

  6. Dry the cylinder block with compressed air. Blow out all bolt holes and passages with compressed air.

    Note: The above cleaning procedure may be used on all ordinary cast iron and steel parts for the engine. Aluminum parts, such as flywheel housing, air intake manifold, oil filter adaptor and the camshaft gear access cover should NOT be cleaned in this manner. Mention will be made of special procedures when necessary.

  7. Be certain that all water passages and oil galleries have been thoroughly cleaned and dried. Install weep hole plugs and precoated pipe plugs. Install new cup plugs using a coating of good grade non-hardening sealant such as Loctite 620 or equivalent.
Inspection of Cylinder Block

Perform the following to inspect the cylinder block: ‪

  1. Visually check the cylinder head mating surfaces for roughness.
    1. If the mating surfaces are rough, repair the component. Refer to section .
    2. If the mating surfaces are not rough, proceed with step of inspection.
  2. Visually check the counter-bore mating surfaces for roughness.
    1. If the counter-bore mating surfaces are rough, repair the component. Refer to section .
    2. If the counter-bore mating surfaces are not rough, proceed with step of inspection.
  3. Visually check the oil galleries for cracks or casting flaws.
    1. If the oil galleries are cracked or have casting flaws, replace the component. Refer to section .
    2. If the oil galleries are not cracked or have casting flaws, proceed with step of inspection.
  4. Visually check the oil passages for obstructions.
    1. If the oil passages are obstructed, clean as necessary. Refer to section .
    2. If the oil passages are not obstructed, proceed with step of inspection.
  5. Measure front main boring bore diameter.
    1. If the main boring bore is not within 67.025-67.050 mm (2.638-2.639 in.), replace the component. Refer to section .
    2. If the main boring bore is within 67.025-67.050 mm (2.638-2.639 in.), proceed with step of inspection.
  6. Measure the main bearing bore diameter.
    1. If the main boring bore is not within 57.005-57.030 mm (2.244-2.245 in.), replace the component. Refer to section .
    2. If the main boring bore is within 57.005-57.030 mm (2.244-2.245 in.), proceed with step of inspection.
  7. Measure the main bearing carrier bore diameter.
    1. If the main boring carrier bore is not within 168.00-168.040 mm (6.614-6.615 in.), replace the component. Refer to section .
    2. If the main boring carrier bore is within 168.00-168.040 mm (6.614-6.615 in.), proceed with step of inspection.
  8. Check cylinder block deck for flatness.
    1. If the cylinder block deck is not flat, replace the component. Refer to section .
    2. If the cylinder block deck is flat, proceed with step of inspection.
  9. Visually check the cylinder block for cracks.
    1. If the cylinder block is cracked, replace the component. Refer to section .
    2. If the cylinder block is not cracked, proceed with step of inspection.
  10. Visually check the cylinder block tapered holes for dirt or debris.
    1. If the cylinder block tapered holes have dirt or debris, clean as necessary. Refer to section .
    2. If the cylinder block tapered holes are not dirty or have debris, reuse the component. Refer to section .

Assemble Engine Assembly

Assemble the engine assembly as follows: ‪

  1. Install the cylinder liners. Refer to section .
  2. Install the crankshaft. Refer to section .
  3. Install the piston and rod assemblies. Refer to section .
  4. Install the oil pickup tube. Refer to section .
  5. Install the oil pump. Refer to section .
  6. Install the vacuum pump. Refer to section .
  7. Install the oil pan. Refer to section .
  8. Install the rear main bearing carrier assembly. Refer to section .
  9. Install the cylinder heads. Refer to section .
  10. Install the rocker covers. Refer to section and refer to section .
  11. Install the exhaust manifold. Refer to section .
  12. Install the intake manifold. Refer to section .
  13. Install the water manifold. Refer to section .
  14. Install the water pump. Refer to section .
  15. Install the oil filter adaptor. Refer to section .
  16. Install the turbocharger. Refer to section .
  17. Install the flywheel housing. Refer to section .
  18. Install the flywheel. Refer to section .
  19. Install the injector pump. Refer to section .
  20. Install the front cover. Refer to section .
  21. Install the crankshaft pulley. Refer to section .
  22. Install the crankshaft vibration damper. Refer to section .
  23. Install the transfer pump. Refer to section .
  24. Install all electrical sensors.

Perform the following to install the engine to the transmission: ‪

To avoid personal injury and damage to the engine, a spreader bar should be used with a sling and adequate chain hoist when lifting any engine. The lifting device should be adjusted so the lifting hooks are vertical to prevent bending the engine lift brackets. To ensure proper weight distribution, all engine lift brackets provided must be used in lifting the engine. Be sure the spreader bar is adequate to prevent lifter brackets from contacting the rocker cover, which may damage the rocker cover. Never lift an engine by any other means.

  1. Connect a suitable lifting device to the engine and connect the engine to the transmission.
  2. Install the engine mounting bolts.
  3. Install the radiator, fan guard, and other related cooling system parts, as necessary.
  4. Install and connect the coolant hoses.
  5. Install and connect the starter motor, alternator, and other electrical equipment, as necessary.
  6. Connect the ECU wire harness to the engine injector pump and sensors.
  7. Connect the exhaust piping to the turbocharger.
  8. Install the intercooler ducting to the turbocharger and intake manifold.
  9. Install the air cleaner ducting, as necessary.
  10. Connect the inlet fuel line to the fuel filter and the outlet line from the fuel filter to the transfer pump.
  11. Refill the crankcase with lubricating oil. Refer to section .
  12. Refill the cooling system. Refer to section .
  13. Connect the battery cables to the battery.
  14. Run the engine to verify repair.