Piston rings
Piston rings |
Matching to a new or rebored cylinder |
1. |
Push the piston rings down into the cylinder one by one, using a piston to position them correctly.
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2. |
Measure the ring gap with a feeler gauge. If necessary, the gap can be enlarged by means of a special file. For ring gap clearance, see
.
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Matching in worn cylinder bore |
Matching is carried out in the same way as with a new or rebored cylinder, but when matching in a worn cylinder bore the rings must be tested in the bottom dead centre position because the cylinder bores there have the smallest diameter.
Fitting piston rings on piston |
I = Front marking on piston crown, arrow points to timing end.
1 = Upper compression ring
2 = Lower compression ring
3 = Steel strip ring (upper oil scraper ring)
4 = Middle ring (oil scraper ring)
5 = Steel strip ring (lower scraper ring)
Oil the piston and rings before fitting. Turn the compression rings so that their gaps are staggered 180°, placing them in line with the ends of the gudgeon pins. Ensure also that the spring gaps in the top and bottom rings of the three-piece oil scraper ring are placed opposite each other.