Talk:Atkinson cycle

An illustration would make this page a lot clearer. (anon user, Aug 23 2005)

Sorry, Carlton Bale! Your edit was not in keeping with the Atkinson cycle heading. The rotary engine has been placed before the four strokes as it more closely conforms to the true Atkinson cycle (one power phase per revolution and different intake/expansion volumes). The original Atkinson engine completed its cycle in one revolution not two revolutions as in a four stroke engine. The different Intake/expansion volumes are achieved by late valve closing in the four stroke engine. This is not really comparable with the original Atkinson design which was based on geometric principles, as is the rotary engine. Regards, Sowilo 19:30, 2 November 2006 (UTC)

Fluzwup; Your previous edit removed a working animation. This has now been reinstated. I have been for many years researching new applications of the Atkinson cycle. The rotary Atkinson cycle engine is currently undergoing computer simulations. This engine represents a major step forward in the use of this thermodynamic cycle. Therefore I would suggest that the entry should remain unaltered unless you have some valid reason why it should not. Regards, Sowilo 11:35, 3 November 2006 (UTC)

Text and diagram don't agree

The text of the "Ideal thermodynamic cycle" section and the PV diagram in figure 1 don't agree. The diagram shows an addition of heat at constant pressure (3-4) that follows the step 2 addition of heat at constant volume (step 2a?). Step 4, the rejection of heat at constant pressure is clearly a rejection of heat at constant volume (5-6) in the diagram. Lastly, there's a reduction of volume at constant pressure (6-1) in the diagram that's not reflected in the text.

Unfortunately, I don't know how an Atkinson engine works (that's why I was looking here!), so I don't know whether it's the text or the diagram that's in error.

ExDonH (talk) 16:21, 18 September 2008 (UTC)

I believe the diagram is wrong. However, it is possible that two different cycles might be called "Atkinson" or possibly the diagram is of what is called the "Atkinson-Diesel" cycle. I am looking into this but am rather on the boundary of my knowledge. Expert advice very much appreciated! Thincat (talk) 13:50, 9 January 2009 (UTC)

alexander.mitsos I am looking at one of the references (Heywood's ICE book) and the cycle is given in four steps isentropic compression, isochoric heating, isentropic expansion, isobaric cooling. This matches several documents online. There may be two versions of the cycle? However the article needs thorough change.

Production year

Clarified to model year, production year can be the same leading to confusion. —Preceding unsigned comment added by Jappahut (talk • contribs) 18:52, 29 October 2009 (UTC)

Since we have the standard dilemma of US vs the rest of the world and the years are not particularly important in this article, I figure it's easier to simply delete the years. All these particular models are current models anyway. Cheers.  Stepho  (talk) 22:23, 29 October 2009 (UTC)

Could be better

Both this one and the article about the Miller cycle are filled with assumptions, spin-off examples, an half-trues.

Miller cycle/engine: It should be possible to find proper references (patent by Ralph Miller?). To my knewledge, this uses altered valve timing to achive a difference between compression and expansion ratio of a 4-stroke engine. This type/technical solution is the one several engine manufacturers use today (the listed examples) to get either reduced compression ratio (knock preventing, boosted engines), or increased expansion ratio (efficiency, naturally aspirated engines e.g. the engine used in later Toyota Prius cars ).

Atkinson (much older) used a special crank mechanism that also gave such difference. Side effect of this mechanism: 1 cycle <=> 1 crankshaft revolution <=> 4 piston strokes. To my knewledge, no mfg use this one, despite that they say that they do (Toyota?).

Is'nt there some student, or anyone else, that have time and can gain some credit for it, to do some research and rewrite these articles?