Any truth to the Quasiturbine hype?

I was reading an article on the web about Quasiturbines and it makes some pretty bold statements about its efficiency vs. piston and Wankel engines. Is its design really so superior that we will be seeing them anytime soon?

I’ve never looked at this engine, but I did some work back in the '80s on what appears to be an almost identical design. My company was doing some “independent verification” of the designer’s claims of efficiency, and we did a pretty thorough analysis of an engine very similar to the one described in your link. While it was much more efficient than a piston engine in both theory and practice, it had several problems which made it impractical. The main problem was that the floating seals were not as effective as they should have been and had a short life, and there were a few other issues I don’t recall as clearly. In short, it was not robust enough to deploy to the real world.

I think the lessons are the same for any new engine design. The existing piston designs are entrenched and any new alternative has to be not just better but orders of magnitude better in order to be worth the effort. This is not a conspiracy on the part of piston engine manufacturers, but just the reality that piston engines are “good enough” for the job they do, they are robust, mechanics and parts are plentiful, and there is substantial infrastructure to support them. A new engine design has the same chicken-and-egg problem that any new paradigm has; customers won’t buy in until there is infrastructure (sales, repair, support) and industry won’t provide infrastructure until there are customers. You see the same thing in every industry.

In the case of the engine I studied, the designers were hoping to market to the oil/gas industry to recover power from wasted well-head gas, but their design would never hold up in those conditions. They might have been better off marketing to the small-scale emergency generator market where lifespan is not as important as fuel efficiency. Regardless of whether that engine was substantially similar to the one in your link, I think it might help answer the OP question about whether we’ll see this soon since I saw that engine twenty years ago and haven’t heard a blip about it since. I’ve seen dozens of new engine designs debut with great promise and die as prototypes because they just weren’t “better enough” (technical term…).

I took a quick look at the webpage and this engine design seems to have the same advantages and disadvantages as a rotary (wankel) engine:

Advantages compared to Otto-cycle piston engine:

Lighter weight for same hp output.
Low vibration
Small size

Disadvantages:

Relies on chamber seals that are still not perfected for rotaries. Non-perfect chamber seals increase emissions, fuel consumptions and limits time between rebuilds.

It also looks like the engine may have a problem with low-speed torque, much like wankel engines.