Repair Methods for Cylinder Block Wear

Long term reciprocating friction between the inner wall of the cylinder and the piston, coupled with poor lubrication, high temperature, and impurities entering the cylinder, can easily lead to wear faults such as inner wall strains, out of roundness, and excessive taper. Cylinder wear can cause problems such as oil burning, decreased power, and idle shaking. Different repair processes can be selected based on the degree of wear to restore cylinder performance.

1、 Minor wear: Boring cylinder grinding repair

When the wear of the cylinder is relatively small and there are only slight scratches or roundness deviations, priority should be given to using a boring cylinder combined with honing for repair. The machine tool performs micro cutting on the inner wall of the cylinder, corrects the roundness and cylindricity errors of the cylinder, and then processes the mesh oil storage pattern through honing technology to improve the lubrication effect. After processing, replace the enlarged piston and piston ring to match the repaired cylinder diameter. This process is cost-effective and is the most commonly used maintenance solution.

2、 Moderate wear: cylinder liner repair

When the cylinder is severely worn or pulled, and the machining allowance of the boring cylinder reaches the upper limit, the repair method of inserting cylinder liner is adopted. Cut and remove the original cylinder wall inside the cylinder, press in a brand new alloy cylinder liner, and then perform precision boring and honing treatment on the inner hole of the cylinder liner. Sleeve repair does not require replacing the entire cylinder block, greatly reducing maintenance costs. Both cast iron and aluminum alloy cylinder bodies are suitable for engines with severe wear but no cracks in the cylinder body.

3、 Local strain: metal spray repair

The inner wall of the cylinder only has local grooves and small scratches, and the overall roundness is still acceptable. Metal thermal spraying technology can be used. Clean the damaged area of the cylinder, spray wear-resistant metal coating, and polish to the standard cylinder diameter size. This method has a very small cutting amount and does not require the replacement of enlarged pistons, making it suitable for minor local damage. However, the wear resistance of the coating is weaker than that of the boring cylinder liner, and it is mostly used for temporary repairs.

4、 Precautions for matching after repair

After the cylinder repair is completed, it is necessary to replace the piston rings with new ones and inspect the supporting components such as the crankshaft, connecting rod, and valves. During assembly, control lubrication and perform low-speed running in for several hundred kilometers to avoid high load operation and ensure that the cylinder wall pattern is fully aligned with the piston ring. Daily use of qualified engine oil and air filter element reduces the entry of dust and impurities into the cylinder, delaying the cylinder from wearing out again.