noun

• A ring on a piston sealing the gap between the piston and the cylinder wall.

  ‘Random leak testing is also recommended because any cylinder leakage indicates a bent valve or a faulty piston ring.’

  More example sentences

  • ‘The downside is that tiny amounts of oil can force their way up past the piston ring into the combustion chamber.’
  • ‘Something was broken and Bill and I suspected he'd blown a piston ring.’
  • ‘There were also many piston and piston ring failures.’
  • ‘All piston rings rely on cylinder pressure for sealing; gas ports just apply the pressure more efficiently.’