It sounds it’s just that: a cleaner two stroke. It fixes the issue of requiring oil mixed in the charge with some reasonable extra complexity compared to a regular (turbo-)supercharged two stroke. But on the other hand it’s hard to believe it could match a four stroke when it comes to emissions and durability.

The design as presented here has a longer compression stroke compared to exhaust stroke which means there will be extra pumping losses compared to a regular four stroke, and is the exact opposite of what high efficiency 4 stroke cycles tend to do (eg. miller cycle). As mentioned in the YouTube comments, ensuring sufficient lubrication for the upper piston rings will probably present a design challenge. Especially given that piston rings and honing patterns are difficult enough to get right even in current engines.

So I guess it may be a better design when compared to a high revving supercharged two stroke (like for example some snowmobiles have) assuming that emission regulations keep getting even stricter. But it’s not that much simpler than a four stroke, and most likely has much higher development costs given the relative novelty of the design. So I’m not really sure If there’s a business case for this, given that four strokes are slowly replacing the current two strokes in pretty much every application, and smaller recreational vehicles will probably go all electric anyway. But as far as novel ICE designs go, this one at least seems like it’s simple enough to be cost effective if ever produced.

Definitely worth a watch 👍🏼

If you skip the first part of stupid motorcycle videos, I’d say yes. It’s long but it goes into detail.

So do catenaries, rails, etc…