QC/T 1074-2017Technical specifications for remanufactured automotive components - Cylinder heads (English PDF)

1 Scope

This standard specifies the terms and definitions, dismantling, cleaning, classification, inspection and repair, exit-factory inspection requirements, and other requirements for the remanufacturing of automobile engine cylinder heads.

This standard is applicable to the remanufacturing of automobile engine cylinder heads.

The remanufacturing of other motor vehicle cylinder heads may refer to this standard.

2 Normative references

The following documents are essential to the application of this document. For the dated documents, only the versions with the dates indicated are applicable to this document; for the undated documents, only the latest version (including all the amendments) is applicable to this standard.

GB/T 26989 Automobile recovery - Terminology

GB/T 28675 Remanufacturing of automotive components - Disassembly

GB/T 28676 Remanufacturing of automotive components - Classification

GB/T 28677 Remanufacturing of automotive components - Cleaning

GB/T 28678 Remanufacturing of automotive components - Pre-delivery inspection

3 Terms and definitions

The terms and definitions, which are defined in GB/T 26989, apply to this standard.

4 Requirements for dismantling, cleaning, classification

5 Inspection and repair

The surface of the combustion chamber can be processed and repaired, by grinding within the specified range, to meet the specified dimensional tolerance requirements; OR match the thickened original cylinder head product drawings or the cylinder head liner, which is specified by the enterprise, to restore its fit clearance. OR pre-treat the surface of the combustion chamber; repair it by adding materials such as spraying or electroplating; then perform grinding, to restore to the original cylinder head product drawings or the dimensional tolerance requirements, which are specified by the company.

5.5 Check all holes in the cylinder head. Carry out pretreatment on the damaged light hole. Repair it by cold welding and other methods, so as to meet the tolerance size requirements, which are specified by the original cylinder head product drawings or the company. For the damaged threaded hole, if the company's requirements allow it, it may use the enlarged threaded hole and the method of re-inserting the wire sleeve, to restore to the original cylinder head product drawings or the dimensional tolerance requirements, which are stipulated by the enterprise.

5.6 Check all parts of the cylinder head for carbon deposits, oil stains, etc. It can be cleaned with cleaning fluids, such as carbon deposit removal and oil removal; OR use high-pressure (cold or hot) water jets, to wash the cylinder head surface, bottom hole, oil passage, water passage and other parts, to remove dirt. For diesel engines, it can use pyrolysis method. For dirt that is hard to clean, it may use such repair methods, as surface shot blasting, local sandpaper grinding, etc., meanwhile prevent the secondary damage to the non-shot blasting surface.

6 Exit-factory inspection requirements

6.1 Each remanufactured cylinder head shall be subject to corresponding flaw detection and pressure testing, as well as inspection of key dimensions, in accordance with the technical requirements of the corresponding remanufactured product or original product drawings.

6.1.1 The surface-repaired remanufactured cylinder head shall be inspected, by fluorescent flaw detection, magnetic particle flaw detection and other flaw detection methods, to ensure that there are no cracks on the surface.

6.1.2 Each cylinder head shall be inspected for tightness, according to the technical requirements of the remanufactured product drawings.

6.1.3 The key dimensions (inner diameter of valve guide hole, depth of valve seat ring, etc.) shall be inspected; corresponding records shall be made.

6.2 Cleanliness testing is required after the cylinder head is machined, to meet relevant requirements.