Measuring cylinders with a bore gauge
1 - caliper; 2 - setting the inside gauge to zero according to caliber A.96137
Cylinder measurement scheme
A and B are the directions of measurement; 1, 2, 3, 4 - belt numbers
Marking of the size group of cylinders on the block and conditional number of the cylinder block
Red arrows - marking of the size group of cylinders on the cylinder block.
The black arrow is the marking of the conditional number of the cylinder block.
Cylinder diameter is measured with a bore gauge (see fig. Measuring cylinders with a bore gauge) in four zones, both in the longitudinal and transverse direction of the engine (see pic. Cylinder measurement scheme). Caliber A.96137 is used to set the inside gauge to zero.
Attention! The cylinders of the block are divided in diameter by 0.01 mm into five classes: A, B, C, D, E. The cylinder class is marked on the lower plane of the block (see fig. Marking of the size group of cylinders on the block and conditional number of the cylinder block). On the same plane, as well as on the main bearing caps, the conditional number of the cylinder block is stamped, which indicates that the covers belong to this block.
In the belt zone 1, the cylinders practically do not wear out. Therefore, by the difference in measurements in the first and other zones, one can judge the amount of cylinder wear.
1. Check if the wear of the cylinders exceeds the maximum allowable - 0.15 mm.
2. If the maximum wear value is greater than 0.15 mm, bore the cylinders to the nearest repair size of the pistons (enlarged by 0.4 or 0.8 mm), leaving an allowance of 0.03 mm for the honing diameter. Then honing the cylinders, maintaining such a diameter that when installing the selected repair piston, the estimated gap between it and the cylinder was 0.05–0.07 mm.