This is a new re-imagined version of the rotary engine.
In sales and marketing, "re-imagined" is a euphemism for "an old idea that we tweaked just enough to peddle to you as something new."
The current prototype is rated 3.5 hp at 10,000 RPM and is expected to produce 5 hp revving up to 15,000 RPM when developed.
Thus far, all they have to support their design justification is "expected" this, "potential" that and the real details of the project are squirreled away in SAE technical papers that cost $24 apiece, costing anyone $73 just to find out what they contain. The site makes no mention of actual brake specific fuel consumption nor emissions. There are plenty of existing designs that already offer superior power density in exchange for dismal efficiency (the Wankel for one, conventional 2-strokes for another), so it better have superior emissions and/or efficiency.
The reason you don't see a lot of rotary applicationsis because of a known design limitation; the seals wear at an unacceptable rate as compared with piston-rings. They require tear-down and rebuild at a rate roughly twice that of piston engines. Advances in metallurgy may eventually solve this, but as of yet, this is price of HP to weight advantage.
That, and they have terrible fuel economy, emissions, and noise.
Rotary engines have been around since 1929. They've been used in aviation since the beginning.
You're confusing radial
piston engines with the Wankel "rotary" design. Wankel's design wasn't even prototyped until the 1950s and
radial engines are still conventional piston engines.
Yes and no, wear and rebuild depends on the application. i've heard form RX7 guys who have little issue and other who have pushed it to limits and rebuild all the time.
Mazda Wankels last a long time under three conditions: 1.) NO TURBOCHARGING. 2.) good apex seal lubrication, and 3.) a serious cooling system.
Turbo RX-7s almost universally benefit from cooling upgrades because Wankels have horrendous thermal efficiency. A LOT of combustion heat goes into the cooling system. Turbocharging makes it worse.
OK, this is the second time you've beat up on BS Flatties. :laugh: The reason they stayed in production so long was because they worked so well.
Flatheads are long term reliable with little maintenance. Foregoing modifications, that is.
That is because they typically have very low HP/L. They also suffer the same poor efficiency/emissions as a Wankel due to the large chamber surface, but flatheads are cheap to produce and low compression engines that can use junky fuel. That made them a practical candidate for small utility applications until emissions laws extended their reach down to lawnmowers.
and with that i agree, in no way is rotary gonna replace piston. they have new piston engine with custom cams that utilize the internal pistons to boost the other pistons. instead of firing or exhaust or whatever, when it goes to compress that air gets dumped in to the cylinder 1 over. the new Fiat 500 Abarth has electronic valves, wicked little thing, comes with straight pipes from the factory it's so efficient! Piston desgin has more room to grow i think.
All of those ideas are at least 50 years old; the only change is that electronic and materials technology has advanced to a point that they are now feasible outside of a research laboratory. Electronic valve control was experimented with as far back as the 1960s. Electronic (analog) fuel injection was realized in the 1950s, digital by the late '70s, production-level by the early '80s, and completely replaced carburetion in the U.S. inside of 10 years (there again, due mostly to tightening smog laws).
Piston engines are a highly mature design. Most of the improvements in fuel usage I expect to see will be due to recovering waste energy from the cooling system and exhaust. Turbochargers do that, but the recovered energy is used to compress air that the engine uses to make more power rather than being used directly to move a vehicle.
This engine and it's problems with reliability on the seals almost caused Mazda to go bankrupt during the RX2 and 3 production.