How to measure and adjust the car piston, piston ring with the main gap it?

1. Piston skirt size and cylinder clearance. Piston skirt size refers to the main piston skirt, thrust surface maximum diameter, the difference between the cylinder bore and skirt size is equipped with cylinder clearance, which is the engine is a major one with the gap, in the slightest difference can be attacked Pull the cylinder and other failures. The skirt size with the inner diameter of the micrometer according to the operating standard careful measurement, when do not understand the measurement of the skirt size position, available micrometer along the skirt main and secondary thrust direction from top to bottom point by point measurement, the maximum diameter value is the skirt size . Common aluminum piston with cast iron cylinder liner, the standard measurement room temperature of 20 ℃, every rise (landing) 10 ℃, discretionary increase (decrease) about 0.01 mm with cylinder clearance.

2. Piston ring opening clearance car repair replacement piston ring caliper must be used to review the opening clearance of the piston ring. For worn cylinders, when reviewing the opening clearance, the ring should be placed in the position with the least wear and tear near the bottom dead center, so as to prevent the tooth from being knocked over and pulling the cylinder. To check whether the clearance between the teeth can exceed the practical limit, the ring should be placed near the top dead center. Experience the process of grinding the cylinder hole, review the opening gap is not subject to status restrictions.

3. Piston ring gap and backlash piston ring gap measured with a caliper. The gap is too small, easy to send card ring, pull cylinder; too easy to leak, oily, major when the piston ring and the shore break. Change the new piston ring should be measured whether the gap is too small; in the piston ring should be reviewed whether the allowance exceeds the allowable limit, especially the first ring. Cylinder first ring at the top dead center easy to wear as a step, in case of the need to level, or the first ring gap will increase dramatically. Piston ring in the ring groove without backlash will pull the cylinder. The ring is pressed into the bottom of the ring groove, the outer surface of the ring should be lower than the outer surface of the shore, or can not be installed into the groove.