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3.2.2.12. Piston rings

The scheme of installation of rings on the piston

1. For modification of SR20DE

2. For modifications of SR20Di and SR20De


Arrangement of joints of piston rings

1. Top compression ring

2. Dilator of an oil scraper ring

3. To a forward part of the engine

4. Lower compression ring

5. Lower disk of an oil scraper ring

6. Top disk of an oil scraper ring

Installation

PERFORMANCE ORDER
1. Before installation of new piston rings it is necessary to check a gap in their joints. Spread out pistons the assembled with rods and new piston rings in such order that a set of rings corresponded to that cylinder in which the gap will be measured in a joint and in which the checked rings will be established.
2. Insert the top ring into the first cylinder and push the piston bottom inside so that the ring in the cylinder became perpendicular to its axis. Push a ring on such depth at which the edge of a skirt of the piston will be made even to the demountable plane of the block of cylinders then get the piston.
3. Measure a gap by the probe and compare result with standard, specified in subsection 3.2.1.1.
4. If the gap is too small (that is improbable if the rings released Nissan are established), then it should be expanded. Otherwise because of a smykaniye of rings during the operation of the engine there will be serious breakages. Best of all it would be necessary to pick up new rings with a standard gap in a joint. At the worst the gap can be expanded, having accurately filed ring joint end faces a thin file. For this purpose clamp a file in a vice with soft sponges, get a ring so that end faces of a joint appeared on both parties of a file, and, slowly moving a ring, remove excessive material. Keep in mind that the ring very fragile and can easily break.
5. It is improbable that the gap in new rings will be too big. If the gap is higher than norm, then be convinced that the ring corresponds to this engine and dimensional group of the cylinder.
6. Repeat the procedure for each ring of the first cylinder, and also for rings of other cylinders. You store the rings and pistons corresponding to the same cylinder together.
7. After selection of rings, measurements and corrections of a gap of a ring can be installed on pistons (see rice. The scheme of installation of rings on the piston).

Prevention

Always observe the instruction of the manufacturer of rings as different manufacturers recommend different procedures of installation of rings for the piston. Do not mix the top and lower compression rings which have different cross sections.


8. The oil scraper ring is established by the first (the lowermost on the piston). This ring consists of three details. Establish a dilator in a flute.
9. Then between a dilator and platforms of a flute of the piston establish one after another the top and lower disks of an oil scraper ring.
10. Establish to the following the lower compression ring.

Prevention

The top and lower compression rings differ on cross section.


11. Before installation correctly orient a ring (orientation tags on compression rings have to be turned up) and establish a ring in an average flute on the piston, at the same time it is forbidden to move apart a ring too strongly.
12. Similarly establish the top compression ring, it is previously correct it having oriented. If the ring has symmetric section, then arrange it so that the identification tag (it is specified by an arrow) was turned up.
13. After installation of rings on the piston place joints according to rice. Arrangement of joints of piston rings.
14. Having repeated these procedures, install rings on other pistons.