- Industrial Engine:
- 3024C (S/N: G4P1-UP; 4241-UP)
- Engine:
- C2.2 (S/N: G7M1-UP)
The combustion insert in In Direct Injection (IDI) engines may experience a temperature that is greater than the temperature of the cylinder head. This is due to the effect of insulation of the joint between the two components and the proximity of coolant flow to the combustion insert. Thermal growth of the combustion insert can cause limited plastic deformation of the cylinder head. On returning to the cold condition, the interference fit is reduced by the permanent deformation. This can counteract the interference fit when the engine is cold. The combustion insert is then held within the cylinder head by the head gasket. In certain cases, the combustion insert will appear to be loose if the cylinder head is removed.
In such instances, loose combustion inserts do not affect the durability of the engine or performance. The characteristics of noise are unaffected.
When the cylinder head is removed, the operator should be aware of loose combustion inserts. Care should be taken.
Upon the reassembly of the engine, clean the combustion insert if the combustion insert has dropped out of the cylinder head. Clean the recess in cylinder head. Do not use abrasive materials to clean the components. Install the combustion inserts into the cylinder head. Grease may be required to aid in combustion insert retention.
An assessment for the depth of protrusion or the recess of the combustion insert to the flame face will then be required. The limit of the protrusion or the recess of the combustion insert is 0.06 mm (0.0024 inch).
The distortion of the cylinder head should be measured. Refer to Specifications, "Cylinder Head" for more information.