Checking the flatness of the cylinder head
Measurement of swirl chamber protrusion from the cylinder head
Carefully inspect the cylinder head for cracks or other damage. If there are cracks, the head must be replaced.
Using a metal ruler and feeler gauge, check the flatness of the mating surface of the cylinder head. With a non-flatness of more than 0.1 mm, it is necessary to regrind the head, while its height must meet the requirements.
Check the condition of the valve seats. If they are burnt, worn, or defective, they must be replaced. If the wear of the valve seat is negligible, they must be lapped. Check the valve guides for wear by inserting the valve stem into them and moving it to the side. The movement should be small. If movement is excessive, remove valve and measure valve stem diameter. Replace valve if necessary. If the valve stem is not worn, the guide bushing is worn and needs to be replaced. Valve guides should be replaced at a service station.
If the valve seats must be reground, this operation must be carried out after the installation of new valve guides.
On diesel engines, inspect swirl chambers for damage and splits. Small cracks are acceptable. Replacing the swirl chambers is necessary if they are severely burned and deformed, or their fit in the cylinder head is weakened. The swirl chamber must be replaced by a specialist. Check the protrusion of the swirl chamber from the cylinder block. To check the protrusion, install the bracket with the dial indicator on the mating surface of the cylinder head. Place the measuring tip of the indicator on the surface of the head. Set the indicator to 0, then move the indicator tip to the vortex chamber. On the indicator scale, read the amount of protrusion of the vortex chamber. Check the protrusion of the other swirl chambers in the same way.