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Measuring piston height

Measuring piston height

Choice of cylinder head gasket


• The thickness of the cylinder head gasket depends on how far the piston protrudes above the sealing surface of the cylinder block.

• There are three gasket thicknesses available. Refer to the table in Engine block

• Before taking measurements, the surfaces must be thoroughly cleaned from soot residue, etc.

• The height of each piston must be measured in two different places.

• Make sure each piston is at top dead centre before being measured as follows:



1. Fit a 78 40 622 Dial indicator in a Measuring jig .


2. Place the measuring jig on the cylinder block sealing surface so that the point of the dial indicator makes contact with the block.

3. Zero the dial indicator.

4. Place the measuring jig over one of the piston measuring points, see illustration.

5. Turn the crankshaft in the direction of rotation while reading the dial gauge. Note the highest value shown on the dial before the pointer starts to go back.

6. Repeat the previous step on the other piston measuring points.

7. Calculate the average value for each piston.

8. Note the maximum value for each of the three pistons in each cylinder bank.

9. Select a gasket thickness from the table, see Engine block depending on the obtained maximum value.