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XTS-210 25hp rotary engine; 1/5th size/weight of diesel piston engines

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31–40 of 56 posts

Re: XTS-210 25hp rotary engine; 1/5th size/weight of diesel piston engines

#31
post #24

Earlier quoted context omitted.

Nit: it's not a turboprop if it's no longer using a turbine.

It's also not a turboprop if it's using a ducted fan. Chuck keeps using that word, I do not think it means what he thinks it means.

Benefit of doubt; they're likely using it as shorthand for 'equivalent to turboprop style/class engine' as an established feature set to have a drop in alternative to.

Re: XTS-210 25hp rotary engine; 1/5th size/weight of diesel piston engines

#32

I wish they had video of the two-stroke design in operation. There's a bunch of their 4-stroke engines being demonstrated by this youtube channel: https://www.youtube.com/watch?v=TDFAjCOM3iQ This one is interesting as it shows difference between their 4-stroke design and a standard wankel rotary in operation, wondering if the two-stoke variation looks like a combination between the two?

It's rotary. There are no strokes in it.

Re: XTS-210 25hp rotary engine; 1/5th size/weight of diesel piston engines

#33
post #28
post #16

Earlier quoted context omitted.

"The first major innovation to the internal combustion engine in over 100 years" claimed there suggests they're not familiar with the Wankel rotary engine upon which their design is based; the modern eccentric shaft version first ran in 1958.

It's not just another wankel engine tho, it's significant modification to the idea and comes with few interesting improvements (and some other drawbacks). Basically , the intake and exhaust is delivered thru the rotor, not ports on the sides, and the seals (the achilles heel of the wankel engines are on the outside of it which in theory would make it possible to both replace them without taking apart whole engine, an…

I know it's a different and likely improved design, but the claim is "the first major innovation to the internal combustion engine in over 100 years". It would be odd if they didn't consider the Wankel itself a major innovation. The Wankel engine is 65 years old.

Re: XTS-210 25hp rotary engine; 1/5th size/weight of diesel piston engines

#34
post #32

I wish they had video of the two-stroke design in operation. There's a bunch of their 4-stroke engines being demonstrated by this youtube channel: https://www.youtube.com/watch?v=TDFAjCOM3iQ This one is interesting as it shows difference between their 4-stroke design and a standard wankel rotary in operation, wondering if the two-stoke variation looks like a combination between the two?

It's rotary. There are no strokes in it.

The manufacturer calls it a two-stroke. Due to the ubiquity of piston engines most people use "two-cycle" and "two-stroke" interchangeably.

Re: XTS-210 25hp rotary engine; 1/5th size/weight of diesel piston engines

#35
post #2

Surprising that there's still that much efficiency to be squeezed out of internal combustion engines!

They are squeezing small size out, not efficiency. You can get more power from a small engine, but you trade long term reliability when you do.

Re: XTS-210 25hp rotary engine; 1/5th size/weight of diesel piston engines

#36

Haven't rotary (Wankel?) engines proven to be unreliable? I love the RX-7 (my dream is to own a FD one day), but IIRC even the more refined Renesis engine on the RX-8 seems to have been proven to be ornery. I think Mazda has a rotary acting as a range extender in their MX-30 EV. I wonder how that will fare.

They were easy to modify for more power, but you trade reliability when you do that. People who ran them stock and followed the maintenance plan generally found them reliable.

Re: XTS-210 25hp rotary engine; 1/5th size/weight of diesel piston engines

#37

This is a pretty cool engine. 25hp is about 18.75 kW so a really good fit for a 15kW generator (sometimes marketed as "whole house" generators) its high RPM (typical of rotary engines) makes it a good match foundation for a turboprop engine. A pair of these driving ducted fan turboprop engines would give you an excellent long duration drone platform with good payload capacity. My guess is the Army might be considerin…

Nit: it's not a turboprop if it's no longer using a turbine.

There is a turbine in the supercharger… does that count?

Re: XTS-210 25hp rotary engine; 1/5th size/weight of diesel piston engines

#38
Previously

[Efficient Rotary Engine Lands Million-Dollar Darpa Contract](https://news.ycombinator.com/item?id=9431379) 76 points, 44 comments, 8 years ago

[LiquidPiston: Efficient rotary engine](https://news.ycombinator.com/item?id=11995735) 87 points, 20 comments, 7 years ago

[LiquidPiston's “inside-out” rotary X-Engine wins Army research contract](https://news.ycombinator.com/item?id=25450477) 278 points, 130 comments, 2 years ago

[“Inside-out Wankel” rotary engine delivers 5X the power of a diesel](https://news.ycombinator.com/item?id=35455286) 255 points, 196 comments, 24 days ago

Re: XTS-210 25hp rotary engine; 1/5th size/weight of diesel piston engines

#39
post #24

Earlier quoted context omitted.

Nit: it's not a turboprop if it's no longer using a turbine.

It's also not a turboprop if it's using a ducted fan. Chuck keeps using that word, I do not think it means what he thinks it means.

lol, love this. Yeah, high bypass turbofan was what I was thinking about, and yes those are "jet" engines. Model airplanes use something called an electric ducted fan or EDF[1], and it has the nice properties in that you can run it over a wide range of speeds if desired. The recent Black Sea MQ-9 incident would, in my opinion, turned out differently if that drone used a shrouded engines for propulsion.

[1] https://www.rc-airplane-world.com/rc-jets.html

Re: XTS-210 25hp rotary engine; 1/5th size/weight of diesel piston engines

#40
post #28
post #16

Earlier quoted context omitted.

"The first major innovation to the internal combustion engine in over 100 years" claimed there suggests they're not familiar with the Wankel rotary engine upon which their design is based; the modern eccentric shaft version first ran in 1958.

It's not just another wankel engine tho, it's significant modification to the idea and comes with few interesting improvements (and some other drawbacks). Basically , the intake and exhaust is delivered thru the rotor, not ports on the sides, and the seals (the achilles heel of the wankel engines are on the outside of it which in theory would make it possible to both replace them without taking apart whole engine, an…

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