Selection of piston repair size

When the cylinder wear exceeds the specified value, or the piston is abnormally damaged, the cylinder must be repaired. The size of the repaired cylinder determines which level of piston to choose. When choosing a piston, you should pay attention to the following points: 1. Select pistons with the same repair size and grouping size. 2. The size of piston skirt is the basis of boring and grinding cylinder. That is, which level of cylinder repair size is, which level of piston 3 should be selected. The same engine must use the same brand of piston to ensure the consistency of its material and performance. 4. The pistons should be matched in complete sets, and the size difference and quality difference should meet the requirements. 5. In a complete set of pistons, the size difference is generally 0.02~0.025mm, and the mass difference is generally 4~8g. The color marks of pin seat holes should be consistent. 6. The matching method is used to match the piston and cylinder of the new car. On the premise of determining the technical requirements of the cylinder, the key point is to match the corresponding piston. 7. The repair size of piston is generally divided into four levels: 0.25mm, 0.50mm, 0.75mm and 1.00mm, and each repair size level is divided into several groups, generally 3-6 groups. The diameter difference between two adjacent groups is 0.010 ~ 0.015mm. When selecting, pay attention to the grouping marks and coloring marks of pistons. 9. Some engines are thin cylinder liners, and the piston does not provide repair dimensions. Only standard series pistons and maintenance series pistons are distinguished, and each series has several groups of pistons to choose from. 10. The repair size grade code of the piston is usually printed on the top of the piston. The piston grouping and cylinder diameter of Santana (1.8L) engine are as follows: