Engine Unit: Inspection

1. Using a gasket scraper, remove all the gasket material from the top surface of the cylinder block.
   Fig 1: Removing Gasket Material From Top Surface Of Cylinder Block

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2. Using a soft brush and solvent, thoroughly clean the cylinder block.
   NOTE: If the cylinder is washed at high temperatures, the cylinder liner sticks out beyond the cylinder block. Always wash the cylinder block at a temperature of 45°C (113°F) or less.

1. Using a precision straightedge and feeler gauge, measure the surfaces contacting the cylinder head and main bearing cap for warpage.

   Maximum warpage: 0.07 mm (0.0028 in.) 

   If the warpage is greater than the maximum, replace the cylinder block.

   Fig 2: Inspecting Flatness

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HINT:

There are 3 sizes of the standard cylinder bore diameter, marked "1", "2" and "3" accordingly. The mark is stamped on the top of the cylinder block.

Fig 4: Inspecting Cylinder Bore Diameter

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1. Using a cylinder gauge, measure the cylinder bore diameter at positions A, B and C in the thrust and axial directions.

   Standard diameter 

   CYLINDER BORE DIAMETER SPECIFIED CONDITION
   
   

   Number Mark	Specified Condition
   Mark 1	94.002 to 94.010 mm (3.7009 to 3.7012 in.)
   Mark 2	94.010 to 94.023 mm (3.7012 to 3.7017 in.)
   Mark 3	94.023 to 94.031 mm (3.7017 to 3.7020 in.)

   Maximum diameter: 94.230 mm (3.7098 in.) 

   If the diameter is greater than the maximum, rebore all 8 cylinders and replace all 8 pistons. If necessary, replace the cylinder block.

   Fig 5: Measuring Cylinder Bore Diameter Using Cylinder Gauge

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HINT:

If the wear is less than 0.2 mm (0.008 in.), using a ridge reamer, grind the top of the cylinder.

Fig 6: Removing Cylinder Ridge

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1. Using a gasket scraper, remove the carbon from the piston top.
   Fig 7: Removing Carbon From Piston Top

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2. Using a groove cleaning tool or broken ring, clean the piston ring grooves.
   Fig 8: Cleaning Piston Ring Grooves

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3. Using solvent and a brush, thoroughly clean the piston.
   NOTE: Do not use a wire brush.
   Fig 9: Cleaning Piston Using Solvent & Brush

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HINT:

There are 3 standard diameter sizes, marked "1", "2" and "3". The mark is stamped on the piston top.

1. Using a micrometer, measure the piston diameter at right angles to the piston pin center line, 30.75 mm (1.2106 in.) from the piston head.

   Standard piston diameter 

   PISTON DIAMETER SPECIFIED CONDITION
   
   

   Number Mark	Specified Condition
   Mark 1	93.902 to 93.912 mm (3.6969 to 3.6973 in.)
   Mark 2	93.912 to 93.920 mm (3.6973 to 3.6976 in.)
   Mark 3	93.920 to 93.930 mm (3.6976 to 3.6980 in.)

2. Measure the cylinder bore diameter in the thrust directions.
   Fig 10: Measuring Piston Diameter Using Micrometer

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3. Subtract the piston diameter measurement from the cylinder bore diameter measurement.
   • Standard oil clearance: 0.090 to 0.111 mm (0.0035 to 0.0044 in.) 
   • Maximum oil clearance: 0.13 mm (0.0051 in.) 

   If the oil clearance is greater than the maximum, replace all 8 pistons and rebore all 8 cylinders. If necessary, replace the cylinder block.

   HINT:

   Use a new cylinder block:

   • Use a piston with the same number mark as the cylinder diameter marked on the cylinder block.
   • The shape of the piston varies for the LH and RH banks. The LH piston is marked with 1 cavity and "2", the RH piston with 2 cavities and "2".
     Fig 11: Subtracting Piston Diameter Measurement From Cylinder Bore Diameter Measurement

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1. Heat the piston to approximately 60°C (140°F), and push the piston pin into the piston pin hole with your thumb.
   Fig 12: Inspecting Piston Pin

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Standard piston pin diameter: 21.997 to 22.009 mm (0.8660 to 0.8664 in.) 

Fig 13: Measuring Piston Pin Diameter Using Micrometer

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1. Using a feeler gauge, measure the clearance between a new piston ring and the wall of the ring groove.

   Standard ring groove clearance 

   RING GROOVE CLEARANCE SPECIFIED CONDITION
   
   

   Piston Ring	Specified Condition
   No. 1	0.030 to 0.080 mm (0.0012 to 0.0031 in.)
   No. 2	0.020 to 0.060 mm (0.0008 to 0.0024 in.)

   Fig 14: Measuring Clearance Between New Piston Ring & Wall Of Ring Groove Using Feeler Gauge

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   If the clearance is not as specified, replace the piston.

1. Insert the piston ring into the cylinder bore.
   Fig 15: Inserting Piston Ring Into Cylinder Bore

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2. Using a piston, push the piston ring a little beyond the bottom of the ring travel, 105 mm (4.13 in.) from the top of the cylinder block.
3. Using a feeler gauge, measure the end gap.

   Standard end gap 

   STANDARD RING GAP SPECIFIED CONDITION
   
   

   End Gap	Specified Condition
   No. 1 piston ring	0.300 to 0.400 mm (0.0118 to 0.0158 in.)
   No. 2	piston ring 0.400 to 0.550 mm (0.0158 to 0.0217 in.)
   Oil ring (Side rail)	0.130 to 0.380 mm (0.0051 to 0.0150 in.)

   Maximum end gap 

   MAXIMUM RING GAP SPECIFIED CONDITION
   
   

   End Gap	Specified Condition
   No. 1 piston ring	1.10 mm (0.0433 in.)
   No. 2 piston ring	1.30 mm (0.0512 in.)
   Oil ring (Side rail)	0.90 mm (0.0354 in.)

   Fig 16: Measuring End Cap Using Feeler Gauge

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   If the end gap is greater than the maximum, replace the piston ring. If the end gap is greater than the maximum even with a new piston ring, rebore all 8 cylinders or replace the cylinder block sub-assembly.

1. Check if the connecting rod is bent.

   Maximum bend: 0.05 mm (0.0020 in.) per 100 mm (3.94 in.) 

   If the bend is greater than the maximum, replace the connecting rod.

   Fig 17: Checking Connecting Rod Is Bent

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2. Check if the connecting rod is twisted.

   Maximum twist: 0.15 mm (0.0059 in.) per 100 mm (3.94 in.) 

   If the twist is greater than the maximum, replace the connecting rod sub-assembly.

   Fig 18: Checking If Connecting Rod Is Twisted

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1. Using a caliper gauge, measure the inside diameter of the connecting rod bush.

   Standard bush inside diameter: 22.005 to 22.014 mm (0.8663 to 0.8667 in.) 

   If the bushing inside diameter is not as specified, check the oil clearance.

2. Subtract the piston pin diameter measurement from the bush inside diameter measurement.
   • Standard oil clearance: 0.005 to 0.011 mm (0.0002 to 0.0004 in.) 
   • Maximum oil clearance: 0.05 mm (0.0020 in.) 

   If the oil clearance is greater than the maximum, replace the bush. If necessary, replace the piston and piston pin with a new piston and pin set.

   Fig 19: Inspecting Piston Pin Oil Clearance

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• Standard diameter: 7.200 to 7.300 mm (0.2835 to 0.2874 in.) 
• Maximum diameter: 7.00 mm (0.2756 in.) 

If the diameter is less than the minimum, replace the bolt.

Fig 20: Inspecting Connecting Rod Bolt

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• Standard diameter: 10.760 to 10.970 mm (0.4236 to 0.4319 in.) 
• Maximum diameter: 10.40 mm (0.4094 in.) 

If the diameter is less than the minimum, replace the cap bolt.

Fig 21: Inspecting Crankshaft Bearing Cap Bolt

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1. Place the crankshaft on V-blocks.
2. Using a dial indicator, measure the circle runout at the center journal.

   Maximum circle runout: 0.04 mm (0.0016 in.) 

   If the circle runout is greater the maximum, replace the crankshaft.

   Fig 22: Measuring Circle Runout Center Journal Using Dial Indicator

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1. Using a micrometer, measure the diameter of each main journal and crank pin.

   Main journal diameter: 66.988 to 67.000 mm (2.6373 to 2.6378 in.) 

   Standard crank pin diameter: 51.982 to 52.000 mm (2.0465 to 2.0472 in.) 

   If the diameter is not as specified, check the oil clearance. If necessary, replace the crankshaft.

2. Check each main journal and crank pin for taper and out of round as shown in Fig 23.

   Maximum taper and out of round: 0.02 mm (0.0008 in.) 

   If the taper and out of round is greater than the maximum, replace the crankshaft.