what causes broken ring lands
Damage From Over-Speeding The Engine. The piston above has been damaged by over-speeding. Look at the piston material between the ring-lands. You can see a big chunk of it is missing and some has been squished thinner, creating a super-wide ring-land. Look at the top ring (bottom of photo). You can see the edge is rounded-over, a sure sign the rings were catching in the exhaust port.