Lets get a little technical: Compression ratios

[Reservoir_Dog]

I took me a bit to go back and find this, but it's a good read.
75% is quite impressive.

http://www.gizmag.com/liquidpistol-rotary/24623/

[Pudfark]

[Reservoir_Dog]

I'm sorry, Pud.
Did I forget to explain to you what a rotary engine is?

[Pudfark]

I'm sorry, Pud.
Did I forget to explain to you what a rotary engine is?

Yes.
I'd rather hear it from chipz...

[HappyHappy]

I took me a bit to go back and find this, but it's a good read.
75% is quite impressive.

http://www.gizmag.com/liquidpistol-rotary/24623/

Lots of press has been given to different designs.
Different combinations of opposed piston, turbo compounding and steam co-generation
have flooded the internet.

That was an interesting read, but started out with an untrue statement.
Unburnt fuel rarely escapes a modern internal combustion engine.

"The internal combustion engine (ICE) has had a remarkably successful century and a half. Unfortunately, it’s notoriously inefficient, wasting anywhere from 30 to 99 percent of the energy it produces and spewing unburned fuel into the air."

True the internal combustion engines today rarely exceed 35% thermal efficiency.
Most average less than 15% in normal transportation service.
The HUGE prime mover engines in ships and diesel power plants manage 50%
at their best RPM.

The only way I have seen that comes close to 75% is various forms of co-generation'such as
gas turbine steam power generation and similar combinations with huge Diesels.

Even then rotary work efficiency is barely 70% and the rest is used as heat or
in a stirling engine (heard of stirling used in this manner, never seen it myself.)

Thanks for the interesting read , but i suspect it to be 90% hyperbole (bullshit).

HH

[Juha]

I suspect the rotary wonder works as advertised, as long as it keeps the initial tightness of the "cylinders". And this requires pretty exotic materials/production tolerances, unless I'm sadly mistaken .

If it only would been produced as 100hp variant, we'd see how it manages "without cooling"

[HappyHappy]

I have serious doubts about the claims because there are limits
on how much mech energy that can be recovered from an air/heat engine
within a given period of time and space. No one seems to have beaten
50% thermal efficiency in a single stage system. And those
are super massive diesels.

Add turbo compounding, steam and or Stirling engines and you
have a huge clumsy but efficient heat engine.

There have been many schemes to get double or more expansion
in a reciprocating engine, and with computers and "Miller/Atkinson cycle"
engines are now commonplace in automotive use. But the returns
are not real good compared to cost and bulk.

25% seems about the limit for efficiency in a petrol/gasoline engine
and 35% for Diesel in automotive use.

HH