2 stroke engine, with conventional flat piston rings, cylinder oil distribution is uneven; only 10% cylinder lubricating oil makes it to the rubbing surface between liner and rings, 30-40% oil goes to exhaust and 30-40% oil is scrapped down. As pressure in the cyliner rises the piston ring presses hard to the liner surface, therefore to prevent high wear of rings, more lubricant is required between liner and piston rings at higher pressure or load.
One of the leading piston ring manufacturer, Federal-Mogul has developed and tested eWAVE piston ring which is able to save approximately 20% lubricating oil, thus saving in operating expanses and reducing pollution too. This is acheived by designing the ring circumference in such a way that it allows more oil to disperse circumferentially, creating a homogenious layer an preventing hydrodynamic breakdown. It has been already tested for more than 20000hours and confirmed reduction in lub oil consumption and wear of liner and ring packs.