QC/T 1070-2017Technical specifications for remanufactured automotive components - Cylinder block assemblies (English PDF)

5.3 Geometric accuracy detection and repair of main bearing housing bore and thrust surface of cylinder block

5.3.1 Assemble the cylinder block assembly according to the bolt torque specification specified by the enterprise. Test main bearing housing bore and thrust face geometry.

5.3.2 If the dimensions and geometric tolerances are out of tolerance, it can use the following methods to repair. Discard if it cannot be fixed.

a) Use mechanical processing method, with a small margin to remove the tile cover or crankcase joint surface Tighten the bolt torque twice. Recover or increase the nominal size of the main bearing housing by machining. Restore its geometric tolerance of geometrical tolerance. Match the corresponding standard or dedicated crankshaft to the machined main bearing housing bore. Recover the final dimensional accuracy requirements for remanufactured products.

b) Repair by adding materials and then processing by metal spraying or welding repair.

5.4 Plane flatness testing and repair on cylinder block

5.4.1 Test the accuracy of the upper plane flatness.

5.4.2 If the flatness is too poor, use the following methods to repair. Discard if it cannot be fixed.

a) machine and cut the upper plane, matching the corresponding thickened cylinder head gasket, restoring the fit clearance.

b) pre-treat the upper plane, repairing by adding materials such as spraying or brush plating.

5.5 Testing and repair of geometry accuracy of cylinder block cylinder bore, stop

5.5.1 Test the geometric accuracy such as cylinder bore, cylinder dimensional tolerance and shape tolerance.

5.5.2 If there is damage or the dimensional and geometric tolerances are out of tolerance, use the following methods to repair. Discard if it cannot be fixed.

a) For the cylinder block assembly that matches the cylinder liner, the cylinder hole and the stop are repaired by removing the material, and the wall thickness is increased to enlarge the cylinder liner or bushing.