It is assumed that the clearance between the ring and the groove pad has already been checked and complies with the standards.
Lay out the piston assemblies with connecting rods and new piston rings in such a way that the set of rings corresponds to the given cylinder on which the joint clearance will be measured.
Insert the top ring into the first cylinder and push it inward with the piston crown so that the ring inside the cylinder becomes perpendicular to its axis. The ring must be located at the bottom of the cylinder, in a position corresponding to the bottom dead center.
The gap in the piston ring joint is measured with a feeler gauge. Compare the result with the set value.
(The article is copied from the website MAZBOOK.ru)
If the gap is greater or less than specified, repeat the measurement to ensure that the ring can be installed.
If the gap is too small, it must be increased, otherwise, during engine operation, the ends of the ring will close, which can cause serious damage. The gap in the piston ring joint can be increased by carefully filing the ends with a thin file. Place the file in a vice with soft jaws and carefully move the ring over it, removing excess material.
The gap may exceed the established one, but should not be more than 1 mm.
The measurement should be repeated to ensure the ring fits properly.
Repeat the measurements for each ring installed in the first cylinder, as well as for each of the rings installed in the other cylinders.
After measuring the gaps in the ring joint and adjusting them, the rings can be installed on the pistons.
The oil scraper ring is installed first (the lowest on the piston).
This ring consists of three parts.
Install the spacer/expander into the groove.
Install the lower oil scraper ring guide. When installing the guides, do not use a ring inserter, as this may cause them to break. Insert one end of the guide into the piston groove, between the spacer and the horizontal surface of the groove, and, holding it firmly, insert the other end of the ring into the groove with your finger. Install the second guide in the same way.
After installing all the oil scraper ring parts, make sure that the upper and lower guides rotate freely in the groove. Arrange the joints of the oil scraper ring according to the drawing.
The middle ring (number 2) is installed next. This ring is stamped with an "R" mark, which should face the piston crown.
Caution! Always follow the instructions on the piston ring packaging; different manufacturers may have different markings. Do not confuse the upper and lower compression rings, as they have different cross-sectional profiles.
Install the piston ring installer, ensure that the marks are facing the piston bottom and move the corresponding ring into the middle groove of the piston. Do not spread the ring joints any further than is necessary to allow the ring to pass over the piston. Instead of the device, you can use metal strips.
Install the upper compression ring in the same way. Make sure the marks are facing up. Do not confuse the upper compression ring (1) with the lower compression ring (2). Arrange the joints of the rings in accordance with the figure.