1. Cylinder aspect: The piston is skewed in the same direction in the upper, middle, and lower parts of the cylinder, which may be due to improper boring of the cylinder causing the cylinder axis to be not perpendicular to the crankshaft axis, or the cylinder axis to shift forward and backward.
2. Regarding the crankshaft: problems with the crankshaft can also lead to cylinder misalignment. For example, the conical shape of the connecting rod journal is not parallel to the main axis, the deformation of the crankcase and improper fit of the crankshaft bearings result in the crankshaft axis not being perpendicular to the cylinder axis, and the crankshaft bending.
3. Regarding connecting rods: Bending or twisting of the small end of the connecting rod can also cause cylinder misalignment. If the bending direction of the small end of the connecting rod is consistent with the inclination direction of the piston, or if the inclination direction changes at the middle position, it indicates that the connecting rod is twisted.
4. Regarding the piston: Misalignment of the piston pin seat hole hinge can also cause cylinder misalignment. If the centerline of the piston pin seat hole is not perpendicular to the centerline of the piston skirt, it will cause the piston to tilt.
5. Other factors: deformation of the cylinder block or cylinder liner, bending and twisting deformation of the crankshaft and connecting rod, processing of the connecting rod liner that does not meet technical requirements, and processing of the piston pin hole that does not meet standards can also cause cylinder misalignment.
Detection method: The deviation of the cylinder can be detected by the following methods: assembling the piston connecting rod without piston rings into the cylinder, tightening the bolts and nuts according to the specified torque, and rotating the crankshaft to make the piston at the upper (lower) dead center; Then use a thickness gauge to measure the clearance between the piston head and the cylinder wall in all directions. If the clearance is the same, it indicates that the assembly is suitable; If there is a significant difference in clearance, or even no clearance in one direction, it indicates the presence of cylinder deviation.
