Motorcycle CYLINDER Block Flatness Tolerance

Motorcycle CYLINDER Block Flatness tolerance

1 technical requirements

1.1 cylinder block and cylinder head should not have oil, coke, scale and debris.

1.2 Water-cooled cylinder block and cylinder head with 3.5-4.5kgf / cm2 pressure for 5min water pressure test, shall not leak.

1.3 gasoline engine cylinder block on the plane to the crankshaft bearing bearing axis of the distance, not less than the original design of the basic size of 0.40mm.

Note: The original design refers to the manufacturer and the technical documents approved under the prescribed procedures (the same below).

1.4 All binding planes shall not have any obvious projections, recesses, scratches or defects. The flatness of the flat surface of the cylinder block and the lower surface of the cylinder head shall be in accordance with Table 1. 1.5 cylinder block crankshaft, camshaft bearing bearing coaxial degree tolerance should be consistent with the original design requirements. Where can be used to compensate for the coaxial coaxial error, to the cylinder at both ends of the crankshaft bearing bearing the common axis as a benchmark, all crankshaft bearing bearing coaxial tolerance of 0.15mm, the cylinder block at both ends of the camshaft bearing bearing Hole common axis as a benchmark, all camshaft bearing bearing coaxiality tolerance of ф0.15mm.

1.6 The rear end of the cylinder block facing the crankshaft at both ends of the bearing bearing the common axis of the end of the whole beating is not greater than 0.20mm.

1.7 The combustion chamber volume is not less than 95% of the original design minimum limit. The difference between the combustion chamber volume of the cylinder head of the same engine should be in accordance with the original design.

1.8 cylinder block, the cylinder head of the bonding surface after processing the surface finish should not be less than ▽ 6.

1.9 Cylinder head with spark plug or nozzle and the heater plug screw thread damage is not more than a tooth, the cylinder block and other screw holes on the cylinder screw thread damage is not more than two teeth. The screw thread after repair should meet the assembly requirements. The dimensions and tolerances of the positioning pins, ring holes and assembly datum should conform to the original design requirements.

1.10 The selected cylinder liner, valve guide, valve seat and seal shall comply with the applicable technical conditions and shall meet the relevant assembly requirements of this standard.

1.11 valve duct bearing diameter should be consistent with the original design size or graded repair size (see Table 2). Valve duct and the hole with the interference is generally 0.02-0.06mm.

1.12 inlet and exhaust door seat bearing diameter should be consistent with the original design size or repair size (see Table 2). Valve seat bearing surface finish is not less than ▽ 5, roundness tolerance of 0.0125mm, with the seat circle with the interference is generally 0.07-0.17mm. 1.13 Inclined dry cylinder liner bearing diameter should be the original design size or the same level of repair size (Table 2). Bearing surface finish is not less than ▽ 6, cylindrical tolerance of 0.0lmm. Cylinder liner and the hole with the interference should be consistent with the original design requirements; no provisions, generally 0.05-0.10mm. There are flange of the cylinder with the interference can be used 0.05-0.07mm; no flange cylinder liner can be used 0.07-0.l0mm. Cylinder liner on the end surface should not be lower than the cylinder block on the plane, nor higher than 0.10mm.

1.14 The inner diameter of the wet cylinder sleeve shall be the original design size or the same grade of repair (see Table 2). Wet cylinder liner and the hole with the gap is 0.05-0.15mm, after installation cylinder liner on the end surface should be higher than the cylinder on the plane, and should be consistent with the original design requirements.