[ew6082]

I see no reason this thing wouldn't lose compression or backflow exhaust gas after wear-in, and wear-in would happen quickly with the cyclic load on those ball bearings. It's a pretty animation but unless they have some spring loading to press the upper and lower rings together the compression (and therefore efficiency) doesn't appear to be durable. There are also some limitations to having a single power stroke per revolution. This can be geared down, of course, but at an efficiency cost.

[yetihehe]

> There are also some limitations to having a single power stroke per revolution.

Unlike one power stroke per two revolutions? That engine has one stroke lasting a full revolution, modern four-stroke has power stroke lasting half of revolution, every two revolutions.

[ew6082]

Which is why we usually have multiple cylinders to deliver smooth power. A V8 is getting power on 4 cylinders each revolution, etc.