What is the piston ring clearance standard? Piston ring three gap detection
The clearance of piston ring is mainly divided into three kinds, which are side clearance, end clearance and back clearance. The side clearance is called the side clearance, which is the clearance between the side and the piston ring groove when the piston ring is installed into the piston, and the standard is 0.04-1.10mm. End gap is also called opening gap, is the piston into the cylinder, the piston ring in the TDC, the gap between the two ends of the piston ring, the standard is 0.25-0.50mm. The back gap refers to the gap between the cylinder surface of the piston ring and the bottom of the piston ring groove, the standard is 0.50mm-1.00mm.
It should be noted that the clearance of the piston ring has been set before the car leaves the factory, there are maximum and minimum limits, and different cars have different, should be based on the actual.
Test method for three gaps of piston rings
1, side clearance: the piston ring from the piston down, and then its side pressure in the piston ring groove and hand fixed, the other hand with the piston ruler of the piston ring and piston ring groove clearance measurement.
2, end gap: the piston ring flat placed on the piston, then the piston to the engine TDC push, use thickness gauge to measure the gap at the opening of the piston ring.
3, back gap: insert the tail of the vernier caliper into the piston ring groove, measure the depth value of the ring groove and record it, then use the vernier caliper to measure the value of the piston ring cross section, the depth value of the ring groove minus the value of the piston ring cross section.
Note on detecting three gaps of piston ring
1, the piston in the engine for a long time, it will inevitably accumulate some oil and carbon. When measuring three gaps, it is inevitable that the accuracy of the value will be affected, so the piston ring and piston should be cleaned before measuring three gaps.
2, when measuring the three gap, try to put the piston ring and piston in the horizontal plane, so as to reduce the error.
3, the three gap value of different cars may be different, so the comparison of the three gap value of the piston ring should check the standard value table of the piston ring gap of their own models.
