- Check Piston Rings for Breakage/Collapse
Broken piston rings manifest themselves during the scavenge port inspection by:
– Lack of “elastic tension’, When
the rings are pressed into the groove by means of a stick – Blackish appearance – Fractured rings – Missing rings.
Piston ring breakage is mostly caused by a phenomenon known as “collapse”. However, breakage may also occur due to Continual striking against wear ridges, or other irregularities in the cylinder wall.
Collapse occurs if the gas pressure behind the ring is built up too slowly, and thereby exerts an inadequate outward pressure. In Such a case, the Combustion gas can penetrate between the liner and ring, and violently force the ring inwards, in the groove. This type of sudden “shock” loading will eventually lead to fracture — particularly if the ring ends “slam” against each other.
