Radically different engine designs, 40 percent efficient and above

[HysteryDiagnosis]

http://www.revetec.com/media_main.htm


http://www.revetec.com/
The Directors are pleased to announce that the X4v2 petrol engine achieved a repeatable Brake Specific Fuel Consumption (BSFC) figure of 212g/(kW-h) or (38.6% engine efficiency) with a best figure of 207g/(kW-h) or (39.5%) at our requested target test of 2,000rpm with a BMEP load of 450kpa (approximately 75% load) and an air/fuel ratio of 15.2:1 using 98 RON petrol and a 10:1 compression ratio. We also achieved a BSFC figure under the same rev and load conditions using an air/fuel ratio of 14.5:1 of 238g/(kW-h) or (34.4%)...


http://peswiki.com/index.php/Directory:StarRotor_Corporation
Feb. 28, 2006

Received by email from Mark Holtzapple:

We have already completed four generations of compressors. So far, our maximum measured isentropic efficiency is 76%. At this measured efficiency, we can calculate that an engine would be about 50 to 58% efficient.

At the moment, we are in the debugging stages of our Generation 5.0 compressor. We expect it to be completed soon... perhaps next week. We hope to show an isentropic efficiency > 80%... we shall see. If we achieve 80%, then it is possible to have an engine that is 58 to 65% efficient.


http://en.wikipedia.org/wiki/User_talk:Gtmnetwork

[whistle]

1. So, where have these engines been for that past two decades?

[HysteryDiagnosis]

2. Do you like them? n/t

[whistle]

4. Certainly, if in fact they can boost fuel efficiency without any trade-off

...or minimal trade-off in performance

[msongs]

3. time to abandon big oil and move on nt

[Raster]

5. And that sentiment is EXACTLY why we haven't seen these types of engines for the past two decades.

The Texas-American Petroleum Mafia, like any good pusher, wanted to make sure their addict customers had a robust thirst for their product. Make no mistake, we could have had far more efficient engines years ago, only it wasn't in the best interests of Big Oil.

[bhikkhu]

8. My stepdad still has an '87 CRX which gets 50 mpg

with his conservative driving habits. I had a Civic the same year and got 47 mpg on the highway.

They stopped making those cars because everyone was buying "bigger, more powerful, and even more luxurious", and the new safety regs have added a great deal of weight and plenty of cost to vehicles.

[cosmik debris]

6. Looks like a variation on the old Wankel engine

http://www.revetec.com/gallery_render_031.htm



I hope it is more successful.

[TreasonousBastard]

7. More like an old aircraft engine...

those are pistons on the outside, and the main difference here is they don't turn a crankshaft, but push on that lobed thingie.

Wankels actually had one combustion chamber in the middle kind of operated by an offset lobed thingie. They were never very fuel efficient or reliable, but they were fast for their size.

Revetec's own numbers say they haven't reached diesel efficiencies yet, and the units don't put out much power. Main question for automotive use is driveability-- throttle response.

[kristopher]

10. Damn those automakers for sitting on these technologies.

http://www.mazda.com/mazdaspirit/rotary/about/

http://en.wikipedia.org/wiki/Mazda_Wankel_engine

http://en.wikipedia.org/wiki/Wankel_engine

[Howzit]

17. Despite high peak power for a given displacement, the Wankel engine does not have

good torque characteristics - you have to keep the revs up or it bogs down. Despite all the improvements to rotor seals, this engine still dumps a lot of partially burnt oil into the exhaust in comparison to a piston engine. Fortunately the catalytic converter can burn that completely into less harmful gases.

The wankel and the Revetec engine have only one thing in common: no crankshaft. Other than that, the Revetec has round pistons with rings that move in linear reciprocating fashion, more similar to the common engine fitted to most cars.

The wankel design has been around for over 50 years and can hardly be cited as technology that has been held back by automakers. It hasn't been used because of poor torque at low revs, poor fuel efficiency, dirty exhaust and poor durability.

From your link: http://en.wikipedia.org/wiki/Wankel_engine#Disadvantages: The Mazda Renesis is state of the art wankel, but hardly taking over the market. The RX-8 fitted with a 1.3 liter version of this engine is EPA rated at 16 mpg city / 23 mpg hwy http://autos.yahoo.com/mazda_rx_8_sport/ . Compare this to the 3 liter BMW 128i with similar power at 19 mpg city / 28 mpg hwy http://autos.yahoo.com/bmw_1_series_128i_coupe/

The Revetec is touted for its superior torque and efficiency - very much not like the wankel...

[cosmik debris]

11. As I understand it

the tri-lobed thingie is supposed to multiply mechanical energy. It was not appropriate for American driving (as you mentioned mileage and reliability)

If this new engine is going to work, it will have to have more going for it than a tri-lobed thingie.

But for me, the bottom line is that the internal combustion engine is a dinosaur and not really appropriate for the long term.

[HysteryDiagnosis]

12. ...

[cosmik debris]

13. ?

are you speechless?

[HysteryDiagnosis]

14. ...

[cosmik debris]

15. Thank you for your support. n/t

[Howzit]

19. Similar in the use of reciprocating pistons, yet

different in using cams in place of a crank and connecting rods.

See radial engine animation: http://www.pilotfriend.com/aero_engines/aero_radial.htm

and wankel rotary animation: http://www.pilotfriend.com/aero_engines/aero_wnkle.htm

[Fovea]

16. It strikes me

that this engine is a low rpm, high torque design whose primary imbalances will be vertical motion, rather than a rocking coupling like big V twins.
Looks like a good plant for hybrids or light aircraft.

Kinda surprised they didn't go with desmodromic valves.

[Howzit]

18. Looks can be deceiving

See post #17

[kentauros]

9. Yayyy!

:)
I'm glad someone else posted this as I seem to post the same and get involuntarily ignored ;)

David HOWELL-SMITH BRADELY - Revetec Cam-Drive Engine