Talk:Rotary engine

Rename to Rotary engine (aircraft)?
Would the perennial confusion (as has arisen again recently) between the aircraft-specific types and the generalised non-reciprocating rotary engines since James Watt's day be made clearer if we moved this article to a more specific disambiguated name, and moved the disambig page to Rotary engine? Andy Dingley (talk) 08:44, 5 April 2016 (UTC)


 * The idea has of course been mooted before (mostly by people who want "rotary engines" to refer to Wankel engines). Main difficulty is that (aircraft) is not the defining distinction (cars, motorbikes etc. have also used engines of the type described in this article, albeit very rarely). Technically more accurate (or specific, anyway) headings, like say Rotary Engines (reciprocating) might be devised - but one wonders very much if any such heading would deflect much of the confusion. Looks more confusing rather than less to me. Might one just gently and kindly ask that people who set themselves up to begin to edit an encyclopedia article read at least enough of the article concerned to determine what it is actually about? --Soundofmusicals (talk) 09:11, 5 April 2016 (UTC)


 * Wankels have been used in aircraft too, IIRC, so Rotary engine (aircraft) would still be problematic because of that. Other alternatives would be Rotary radial engine or Rotary engine (radial), as they are sometimes called a type of radial engine, but I'm sure those will also bring objections also. I'm not sure there is a better choice of disambiguator that doesn't cause more problems than it solves. - BilCat (talk) 09:59, 5 April 2016 (UTC)
 * Rotary radial engine is the best of these, and an improvement on the current situation. It's clear, accurate and doesn't lose too much from COMMONNAME. Andy Dingley (talk) 14:24, 5 April 2016 (UTC)
 * I think Rotary engine (aircraft) has the vast virtue of clarity and it meets COMMONNAME better than anything else which might be concocted. The land-based variants are I think a couple of motorcycles with in-wheel engines (and handling to match) and one or two esoteric racing cars. We can live with those as outliers still under "aircraft", nit-pickingly inaccurate as that might be. We're an encyclopedia, not an ontology. Andy Dingley (talk) 14:14, 5 April 2016 (UTC)


 * I like Rotary radial engine the best also, but I think that some will object to using radial in the name. To them, radial engine refers only to the fixed type, and the rotary engine isn't fixed. I'd recommend we go ahead and make a formal RM proposal for Rotary radial engine, and post notices on relevant project pages, including MILHIST and WPAIR. We'll see what happens then. - BilCat (talk) 16:16, 5 April 2016 (UTC)


 * If this is to get serious - I'd like to record a massive great vote for the status quo. Making up a name for something that already has a perfectly good name already is stark daft. Especially as whatever you called it you'd confuse the terminally confused and score the objections of the objectionable. Why not just go the full hog and call it a Twirly Wirly Pop Pop? and change all the WW! aircraft articles to match too? Makes just as much sense. --Soundofmusicals (talk) 21:37, 5 April 2016 (UTC)


 * I didn't make up the name "rotary radial engine" - see http://www.google.com/search?q=%22rotary+radial+engine%22&sourceid=silk&ie=UTF-8. At 1500 ghits, it's clearly not as common, but it's a natural disambiguator. I don't really expect the name to be changed, but the current one's place as the primary topic has always been debatable, which is an indication it isn't the clear primary topic. - BilCat (talk) 23:56, 5 April 2016 (UTC)

Are all rotary engines (in our sense) even of radial layout? other cylinder layouts are (were) very rare, but they do (did) exist, and are mentioned in the article. Look, assuming that this is a serious question (which I doubt) there are three possible "disambiguation" questions that might arise here.


 * 1. Differentiation between Wankel engines (also actually called rotaries) and reciprocating rotary engines.

This remains the only reason that is not totally trivial (why I mention it first). We have discussed this at considerable length in the past, and repeatedly the consensus has come down on the side of the status quo. Wankels do at least have an alternative name, which "our" rotaries do not.
 * 2. Differentiation between a Radial engine (stationary) and a Rotary engine.

Does anyone seriously want to add a qualifier to Radial engine? Because that's the only way to tackle this particular confusion. Either that or get rid of the Rotary engine article altogether, and merge it (perhaps as a discrete section) with Radial engine? Hasten to add that this strikes me as grossly inappropriate too.
 * 3. Differentiation between a (water, wind, steam or gas) turbine and a rotary engine.

This seems pretty far-fetched - but this topic seems to have been spawned by an example of this kind of thing. It stems from ignorance. Turbines are simply not called rotaries. This may be a problem, but it is NOT a disambiguation problem, which is necessarily caused by ambiguity (two things having the same name).

Excuse me if I am taking a sledgehammer to a walnut - but this particular nut does needs to be cracked (preferably smashed) so we can get onto other things. -Soundofmusicals (talk) 01:12, 6 April 2016 (UTC)

Distinction between "rotary" and "radial" engines
Most people coming "fresh" to this article believe that "rotary engine" means a Wankel and that what we call a "rotary" in this article is a radial. Our initial task here is to explain that no, we are not talking about a Wankel here - and no, in spite of how the picture looks, it is not a radial either. I estimate we actually convince somewhere around 15% or so of readers that this is the case - the rest just shrug their shoulders and say to themselves "Wikipedia is so unreliable!" In view of this we really don't want any tortuous, confusing matter creeping into the lead (lede) - really, we don't. Personally, I have my doubts about that bit about the museum model being in the article at all - with even stronger doubts about it belonging in the lead. If it is not to be moved to a more appropriate place (or simply removed altogether) then it does need to be very carefully worded. --Soundofmusicals (talk) 23:31, 8 November 2016 (UTC)

The 7 piston gif animation is wrong
The pistons and timing are shown correctly but they are NOT moving the cam attached to the center correctly. the motive force should be directed to the cam's other (offset) pin, NOT the center pin directly (the engine can't rotate if pistons are trying to move the center/anchor pin!). — Preceding unsigned comment added by 2604:2000:F151:8E00:5843:398E:7BF7:62EC (talk) 17:48, 14 March 2017 (UTC)

As of today ( 185.24.186.192 (talk) 09:40, 23 May 2017 (UTC) ) the gif is correct: it's true that "the motive force should be directed to the cam's other (offset) pin, NOT the center pin directly", but this is the case in current gif. Maybe it was wrong when previous observation was done, it wont show in history of the article but in history of gif, which i didn't check.

(Please sign comments with 4 tilde marks "~")

NOT productive (on the whole) to argue about accuracy of sources or externally acquired illustrative material. Just remarking. --Soundofmusicals (talk) 04:51, 26 May 2017 (UTC)

Total-loss lubrication
Our explanation for this was, I believe, pretty good so far as it went, but as another editor insisted, the "two-stroke style" lubrication system was inevitable without a way of circulating oil back into the crankcase. In other words, what remained of the (castor) oil had no way out but the exhaust. The point as we made it, and the point our editor wanted to substitute are not incompatible, if you can get your head around it. (No way in but HERE, no way out but THERE). Comments welcome - but discuss here before making further changes. --Soundofmusicals (talk) 02:20, 14 June 2017 (UTC)

good for me, maybe could be written slightly better, but no editing really needed. Gem fr (talk) 10:22, 14 June 2017 (UTC)

Wankel revisited!
The Wankel engine is only mentioned here at all to make it clear that it is nothing whatever to do with this article. The Wankel isn't a piston engine - and in no way has anything to do with the case. Any objection to the BR.2 being described as the "ultimate" rotary would have to be based on (say) other very late examples, such as the SSW productions from Germany. --Soundofmusicals (talk) 02:48, 28 September 2017 (UTC)
 * The removal was made and remade because saying one British engine is the 'peak' of development is an unsupportable statement. It is a matter of opinion, it is Anglo-centric, and disproving it is as easy as saying, "well, there was another engine that was different and designed after it."  "Peak" implies best, last, or highest and that's just not what we're talking about here.  It's a weak statement and adds nothing to the article.  It doesn't belong in an encyclopedia and is unsupported in the paper encyclopedia that is cited to support it. --Winged Brick (talk) 17:59, 29 September 2017 (UTC)
 * "Pinnacle of rotary engine development" is a direct quote from Gunston. Gunston meets RS for such things. You do not. Andy Dingley (talk) 18:54, 29 September 2017 (UTC)
 * "Pinnacle" is a meaningless opinion. It is not factual and does not add to the article.  RS, my behind. --Winged Brick (talk) 22:14, 29 September 2017 (UTC)


 * Gunston was often opinionated, and error prone at times, but he was a noted author, and well-known and respected in the aviation field. His works are generally accepted as reliable until proven otherwise by better sources. - BilCat (talk) 22:46, 29 September 2017 (UTC)


 * I think here we are probably less likely to upset the ignorant with "Gunston style rhetoric" by paraphrasing what he is talking about rather than directly quoting him. Hypothetical rotary engines capable of developing more power, more efficiently than the BR2 were just no longer feasible. This is not (in itself) ethnocentric - just an encyclopedic statement of fact. Wankels are of course a total and utterly irrelevant "red herring" - introduced and hammered by Mr. Winged Brick - since the Wankel is NOT (trying very hard to be patient here) a "rotary" engine at all, at least in the context of this article. To talk about the Wankel (a brilliantly innovative concept, whatever the long term success of its application) as if it were in any way connected with the primitive and totally unrelated subject of this article does it no credit. The Wankel has its own article. See the disambiguation hatnote at the head of this article. --Soundofmusicals (talk) 01:56, 30 September 2017 (UTC)

WP:Administrators' noticeboard/Edit_warring Andy Dingley (talk) 22:43, 29 September 2017 (UTC)

common courtesy
In History->Millet this appears inline : "...so must be considered ...". This is an encyclopedia, you should not be giving the reader directives, would appreciate if someone rephrases this. — Preceding unsigned comment added by 77.138.224.125 (talk) 11:50, 19 June 2019 (UTC)

Ralph Watson Special Engineer
A new editor added the following:


 * Early 2020 a rotary aircraft engine incorporating a novel oil delivery system, which overcomes the shortcomings of the total loss systems severely inhibiting previous designs, was built as an amateur experimental project by the late Ralph Ogden Watson, Auckland New Zealand. Fully tested and proven, the engine as from 2020, is on display in running condition at the Wings and Wheels Museum, Wanaka, New Zealand, a venue for International air displays. The engine is illustrated and described in detail within the book published by Trevor R. Sheffield, “Ralph Watson Special Engineer”, ISBN 0-476- 01371-2, now out of print. However a Google search will disclose a copy freely available on the internet.

This is potentially very interesting indeed - but the sources mentioned do not appear to be RS - and I am also concerned if this is even an actual example of the subject of this article, or if it is more like a variant on the Wankel theme - in any case we need more details for it to go into THIS article. -Soundofmusicals (talk) 01:56, 12 July 2020 (UTC):


 * Sorry, but the graphic on this source looks a lot more like something from an engine with "rotors" (a la Wankel) rather than cylinders - although the caption calls it a "component" so it is hard to be sure. Actually it seems to resemble a planetary gear box (an unlikely component for the kind of "rotary" we are talking about here, unless it is a bi-rotary?). And in any case it looks as if we still don't have a "reliable" source in Wikipedia terms, although I remain open to correction on this one. The "best" source listed on the web is published by the author, apparently an associate of the inventor. --Soundofmusicals (talk) 15:02, 12 July 2020 (UTC)

A Google search will disclose absolute details and that the source is genuine and a rotary aircraft engine is correctly described.Trevshef (talk) 23:22, 12 July 2020 (UTC)


 * That doesn't prove the engine is notable, or that a self- published source, with an author whose name is quite similar to your username, is reliable either. If you are the author, you must disclose that information if your going to edit Wikipedia in areas related to the book. You can participate on this talk page after making such a disclosure, but you cannot edit any articles related to the subject if the book. Your book can be blacklisted if you continue to push it without following the guidelines. Please take that warning seriously, as Wikipedia does not tolerate undisclosed conflicts of interests. - BilCat (talk) 23:31, 12 July 2020 (UTC)


 * @Trevshef About your remark above. To be fair, it is up to you to provide the information required to get this up - just asking someone else to confirm it for you is not the way to go. Although I actually have Googled it, without finding a reliable source, or the information required. On the other hand it is easy to miss stuff if one is not sure exactly what one is looking for, so it is far from impossible you might be able to supply the deficiency. -Soundofmusicals (talk) 22:39, 13 July 2020 (UTC)

Should the opening paragraph be in the present tense ?
The opening paragraph seems a little jarring to me as it continually refers to rotary engines in the past tense. Even though the "heyday" of rotary engines was in the past there are still many working rotary engines in operation today, either on rebuilt or replica World War I aircraft, or as noted above in new style rotary type engines such as the Wankel. That being said, even if there were no working rotary engines today the design is still valid and could be built by anyone who was so inclined to do so.

I am new to editing so am not sure if I am allowed to make these changes unilaterally. Rags17 (talk) 08:36, 8 November 2022 (UTC)


 * Per MOS:TENSE, the engines still exist, so we use present tense. I believe there some examples still used on flying airplanes, usually WWI-era, but they also exist in museums. BilCat (talk) 09:06, 8 November 2022 (UTC)

Different Wankel engine and rotary engine
Hello English Wikipedia editors! What is the difference between a rotary engine and a wankel engine? After I looked it up on Google, most of the information there states that the two engines are the same. Is this true? Please provide references that support your opinion. Cheers Badak Jawa (talk) 03:21, 7 March 2024 (UTC)
 * I suggest you read this article, and the Wikipedia article on the Wankel engine. The two concepts are entirely different, and do not resemble each other in the slightest. The Google issue arises because the term 'rotary engine', which was first applied to the device described here, has since been applied to the Wankel (and to a few other devices). Google searches for terms, and accordingly confuses the two. There is no 'opinion' involved here, it is a demonstrable fact that an internal combustion engine consisting of a series of pistons and cylinders revolving around a stationary crankshaft is not the same thing as an internal combustion engine with a rotor revolving in an epitrochoidal housing. There is a disambiguation note at the top of our article directing people looking for information on other devices to the relevant page. AndyTheGrump (talk) 07:35, 7 March 2024 (UTC)

Wrong pictures and description.
This information is wrong. These are pictures of radial engines, not rotary engines. Rotary engines don't have cylinders. Someone needs to fix this. Wikipedia must pride itself on misinformation. 50.168.146.202 (talk) 16:24, 4 April 2024 (UTC)


 * There is a hatnote at the very top of the article directing readers to the article they may be looking for: . Nimbus (Cumulus nimbus floats by)  16:49, 4 April 2024 (UTC)
 * After all these years, and people still refuse to actually read and comprehend the article. BilCat (talk) 02:48, 19 April 2024 (UTC)