4.7.16. Installation of piston rings

Before installation of new piston rings it is necessary to check gaps in their locks. It is meant that side gaps of landing of rings in flutes of pistons are already checked and meet accepted standards.


  1. Spread out conrod and piston assemblies with sets of rings on a working surface of a workbench. From this point each set of rings will "be rigidly tied" to the piston. Now it is possible to start measurement of gaps in locks of rings.
  2. Fill top (No. 1) a compression ring in the first cylinder of the engine and level it perpendicularly, having pushed the piston bottom down. The ring has to appear around the lower bound of the working course of rings in the cylinder.
  3. Determine gap size in the ring lock by means of the probe of lezviyny type. The edge(s) of the probe has to slip hardly in the lock. Compare result of measurement to requirements of Specifications. If the size of a gap exceeds the limit of admissible range in this or that party before taking any actions for correction of a situation (see below), once again make sure that did not mix a ring.

Measurement of a gap in the lock of a piston ring

  1. If the gap is too small, it can be expanded by boring with a file with small tooth. Clamp a rectangular file in a vice, then put on a ring the lock a file so that the end of the last appeared in a circle. Slowly pull a ring on yourself, removing excess of metal from its end faces in the lock. Having reached the end of a file, remove a ring, again check a gap, in case of need repeat the procedure.

Do not push a ring from yourself at all on a file as at the same time edges of the lock will meet, and the risk of destruction of metal is high!

  1. The size of a gap should not exceed value of 1.02 mm. Once again make sure that the acquired sets of rings meet according to the characteristics requirements of the engine of your car.
  2. Repeat the procedure for the remained rings (the second compression and oil scraper) the piston of the first cylinder, then for rings of all other pistons. Remember that now each set of rings "is unambiguously tied" to the piston on which has to be established.
  3. Having checked and having modified properly gaps in locks of rings, it is possible to start their putting on on the pistons.
  4. The first on the piston the oil scraper (lower) ring puts on. The oil scraper ring consists of three separate sections. At first fill a spring dilator in the lower flute of the piston. If the dilator is equipped with an antirotational uvula, track that the last got to reciprocal drilling in a piston flute. Now establish the lower working section of a ring in a flute. In order to avoid casual damage of working sections of an oil scraper ring do not use any tool for their installation, - just bring to a flute under/over a dilator at first one end of section, densely press it a finger and, moving on ring perimeter, fill the rest. In the last turn the top working section of a ring is established.
  5. Having put all three components of an oil scraper ring in the lower flute of the piston, check freedom of rotation (sliding in a flute) the top and lower working sections.
  6. The second (lower) compression ring is established by the following. The ring has to be established by marking up (to the piston bottom).

Strictly follow instructions of manufacturers of rings which are usually printed on packing of a set. Do not mix the second compression ring with first (top) - they have various cross section

The top and lower compression rings differ from each other in a section form

  1. Having used a special dilator and having tracked that the ring was turned by marking up, put him in an average flute on the piston. Try not to part the ring lock more than it is really necessary for its free putting on on the piston.
  2. Working in a similar manner, establish the first (top) compression ring (marking up). Try not to mix the top ring with the second.

On some engines the top compression ring is not marked and can be established by any party up.

  1. Working in a similar manner, serially complete with rings all remained pistons.