Cylinder Block and Cylinder Head – Inspect and adjust


Clean all of the coolant passages and the oil passages.
Check the cylinder block for cracks and damage.
The top deck of the cylinder block must not be machined. This will affect the depth of the cylinder liner flange and the piston height above the cylinder block.
Check the front camshaft bearing for wear. If a new bearing is needed, use a suitable adapter to press the bearing out of the bore. Ensure that the oil hole in the new bearing faces the front of the block. The oil hole in the bearing must be aligned with the oil hole in the cylinder block. The bearing must be aligned with the face of the recess.

Cylinder Head Inspect

Remove the cylinder head from the engine.
Remove the water temperature regulator housing.
Inspect the cylinder head for signs of gas or coolant leakage.
Remove the valve springs and valves.
Clean the bottom face of the cylinder head thoroughly. Clean the coolant passages and the lubricating oil passages. Make sure that the contact surfaces of the cylinder head and the cylinder block are clean, smooth and flat.
Inspect the bottom face of the cylinder head for pitting, corrosion, and cracks. Inspect the area around the valve seat inserts and the holes for the fuel injection nozzles carefully.
Test the cylinder head for leaks at a pressure of 200 kPa (29 psi).

Flatness of the cylinder head
(A) Side to side
(B) End to end
(C) Diagonal

Measure the cylinder head for flatness. Use a straight edge and a feeler gauge to check the cylinder head for flatness.
• Measure the cylinder head from one side to the opposite side (A).
• Measure the cylinder head from one end to the opposite end (B).
• Measure the cylinder head from one corner to the opposite corner (C).

Resurfacing the Cylinder Head

The bottom face of cylinder head can be resurfaced if any of the following conditions exist:
• The bottom face of the cylinder head is not flat within the specifications.
• The bottom face of the cylinder head is damaged by pitting, corrosion, or wear.
The thickness of the cylinder head must not be less than 94.80 mm (3.7323 inch) after the cylinder head has been machined. If the bottom face of the cylinder head is resurfaced, the recesses in the cylinder head for the valve seat inserts must be machined. The valve seat inserts must be ground on the side which is inserted into the cylinder head. Grinding this surface will ensure that no protrusion exists above the bottom face of the cylinder head.

Piston Height Inspect

If any of the following components are replaced or remachined, the piston height above the cylinder block must be measured:
• Crankshaft
• Cylinder head
• Connecting rod
• Bearing for the piston pin
The correct piston height must be maintained in order to ensure that the engine conforms to the standards for emissions. The top of the piston should not be machined. If the original piston is installed, be sure that the
original piston is assembled to the correct connecting rod and installed in the original cylinder. Three grades of length of connecting rods determine the piston height above the cylinder block. The grade of length of a connecting rod is identified by a letter or a color. The letter or the color is marked on the side of the connecting rod.


Use Tooling in order to measure the piston height above the cylinder block. Use the cylinder block face to zero Tooling.
Rotate the crankshaft until the piston is at the approximate top center.
Position Toolings  in order to measure the piston height above the cylinder block. Slowly rotate the crankshaft in order to determine when the piston is at the highest position. Record this dimension.