Talk:Rotary engine

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[edit] Various discussions

I'm having a hard time grasping how the engine works. An inside cutaway would help tremendously. -- 15:32, 20 November 2006 (UTC)

Just imagine a normal radial engine, except fix the crankshaft and attach the propeller directly to the engine block.132.10.250.80 (talk) 20:27, 11 January 2008 (UTC)

See also Talk:Rotary engine (disambiguation)

For clarity, I am removing the bullet from the fourth paragraph in the history section starting with "Another advantage, not realized at first"

In the history section, it says Balzer was interested "for two main reasons:" and then lists 3 bullet points. The third point is described as an "advantage, not realized at first", making it seperate from the reasons Belzer was first interested in the design.

216.24.148.2 02:55, 7 January 2006 (UTC) Shimonyk

The Mazda mention at the bottom is out of place, isn't it? That's a pistonless design, as seen here: http://en.wikipedia.org/wiki/Pistonless_rotary_engine

[edit] Gnome

The next major advance in the design was Louis and Laurent Seguin's Gnome series from 1908. Believed to have been inspired by the American Adams-Farwell automobile's rotary engine concept, they started their development with the seven cylinder Gnôme Omega No.1,

I'm almost certain this is wrong. The Gnome originally started as a German engine, the Gnom, which was a single-cylinder stationary engine for industrial use designed by Oberussel. The Seguin's basically adapted the Gnom design into a rotary. I don't see where the Adams-Farwell concept comes into it. Maury 22:20, 22 February 2006 (UTC)

[edit] Radial, not rotary

This engine is called a Radial engine, not a rotary engine!

Nope, it's a rotary engine. It's rather different operation than a conventional radial (as you would know if you had actually read the article instead of vandalizing it). This was the original rotary engine. Wankels and other pistonless designs are at fault for creating the naming confusion because they adopted a name that had already been in use for some 50 years. - Emt147 Burninate! 07:00, 17 March 2006 (UTC)


  • Actually, I think it is called the Radial Engine and not Rotary Engine. I have an old book back home from the Shuttleworth Collection which refers to this type of engines as Radial Engines. You can also see here that the engines are called Radial Engines.

    The article is also rather confusing by saying that Rotary=Radial and Other Types of Rotary=Wankel Engine. In that case, what exactly is the definition of Rotary Engine?

    Also, have a look at what HowStuffWorks.com has to say about rotary and radial engines:
    *Radial Engines
    *Rotary Engine

    In my understanding, a Radial engine is an engine where all the pistons share the same hub on the crankshaft. A Rotary engine on the other hand is a type of engine that does not utilise pistons to generate power, using rotors instead.
    --Pavithran 18:20, 25 September 2006 (UTC)
Sorry, you're wrong. And I say this as someone who has actually run at least one example of each of the engines you are talking about.
You are apparently confused because rotary piston engines look extremely similar to radial engines. You cannot easily tell the difference from a photograph. In fact, you stated above that rotaries are actually radials and then linked to a page showing how a radial works. You will note that that animation does not have spinning cylinders, and thus is not a rotary. I assume your book from Shuttleworth is a similar confusion, but I cannot be sure.
All rotary piston engines are a subclass of radial. The distinction is that in the rotary the cylinders spin, and in a radial they do not. On the other hand, pistonless rotary engines, or Wankles and their work-a-likes, are very different designs. It is too bad people refer to these as rotaries, but that's just the way it is. They could have just as easily referred to jet engines this way, but luckily rotaries were not long forgotten in the 30s like they were two decades later.
The article is correctly named. Maury 21:24, 25 September 2006 (UTC)
Mr. Maury is correct about this. Gzuckier 21:42, 25 September 2006 (UTC)
  • I see, so you mean there is a different kind of engine altogether called Rotary Piston Engines and these engines look similar to Radial engines but work differently ?

    Okay, in that case, could you give me a source that explains how these Rotary Piston Engines work?

    Also, what do you mean by "spinning cylinders"?
    --Pavithran 06:59, 26 September 2006 (UTC)
Yes, I know the naming is very confusing! Here's an animation of how the Gnome works, the Gnome is sort of the canonical rotary: Gnome. If you look at the shaft you'll notice the actual operation is identical to the radial, the pistons have the same operating cycle and layout. The only different is what part moves and what part is bolted to the aircraft. If this link is not in the body of the article, it should be! Maury 12:31, 26 September 2006 (UTC)
  • Wow! Fantastick link there Maury. Great job indeed. I have e-mailed the owner of the website to request for permision to use that image on Wikipedia. Hoping to hear from him soon. If he agrees, we can start editing the article to properly explain the confusion between Rotary and Radial. Apparently, the rotary engine that is shown in the first pic of the article is called Gnome Rotary Engine.

    --Pavithran 19:42, 26 September 2006 (UTC)
No problem! It's the Gnome that I have actually seen running. It may have been a replica actually, but I don't think so. Maury 21:33, 26 September 2006 (UTC)
  • Okay, bad news, the owner of the website does not want to allow use of his material on Wikipedia, so this means we need to find an alternative. --Pavithran 20:59, 27 September 2006 (UTC)

[edit] Clarifying Paragraph

  • I've added a section at the end of the article clarifying the difference between Radial engines and Rotary engines. --Pavithran 23:26, 27 September 2006 (UTC)

[edit] Westinghouse and the Rotary steam engine=

Should G. Westinghouse and the Rotary steam engine direct here? J. D. Redding

[edit] Sopwith Camel

There's a reference in the article to the Sopwith being 'notoriously dangerous' - there's a lot of discussion about the handling characteristics of that aircraft on the talk page relating to the Camel. This particular phrase, I think is far too simplistic and should be removed if it can't be specifically verified. Scoop100 (talk) 12:46, 26 April 2008 (UTC)

[edit] Erm

What does the Rotary engine emit, i.e. CO2? —Preceding unsigned comment added by Indexdozen (talk • contribs) 20:28, 26 April 2008 (UTC)

[edit] Rotary Engines - Castor oil, diarrhea, throttle, gyroscopic forces, and the blip-switch

A recent editor states: "I don't think there is very much doubt that pilots of rotary engined aircraft inevitably ingested castor oil - nor what the medical effects would have been!"

Chad Wille, Director of Maintenance at Old Rhinebeck Aerodrome, disagrees.

Mr Wille states as well that the engines were not "unthrottleable" and did not have terrible torque effect. Mr. Wille's comments are buried in the middle of a lengthy article, but he states that these are myths and are the result of dramatic embellishment in 1930's pulp magazines written by men who never flew behind a rotary engine. He asserts that, while the engines do throw a castor oil mist, it is not enough to effect a pilot. He also states that torque and gyroscopic precession are hardly felt on the le Rhone 80 hp, even in very small airframes like the nieuport 11, and the gnome 160 hp does not affect the planes in ways that mild control pressures (far less than the effort required when flying the plane in a crosswind) cannot correct.

Rotary engines actually did have a throttle of sorts: Mr. Willes states that rotary engines are not "unthrottleable", as is asserted in the section concerning use of the blip switch. He states that all rotaries have two piece air/fuel throttles that, once understood, act very much like their modern single-piece counterparts and allow single lever graduated throttle response from idle to full speed. He does support the wiki article's statement regarding the Gnome monosoupape which had a cockpit switch allowing the pilot to run on 1, 3, 6, or all 9 cylinders.

Use of the Blip-Switch: Mr Wille writes that factory manuals often discouraged cutting the ignition dead by use of the blip switch and emphasized the use of the throttle instead. He states that the blip switch is more frequently used today due to modern air-fields which don't always allow aircraft to land directly into the wind, unlike WWI fields which generally were large and square. The instant and full bursts of power allowed by the ignition-shorting blip switch (with the fuel/air throttle set in the right place for full power) allows the pilot to put a blast of air over the plane's control surfaces to help with steering to a stop. He states that modern pilots of these old an valuable aircraft land "on the blip" for the extra margin of safety and control since it frees the pilot from having to fiddle with mixture lever in any way during landing.

The above has been paraphrased from:

http://www.oldrhinebeck.org/technical_corner_001.htm —Preceding unsigned comment added by SonjaZ (talk • contribs) 19:31, 30 April 2008 (UTC)

Wow, erm, okay. Someone really needs to go in and clear up this stuff as the article is a mess right now. The refs are poorly formated for a start and I don't think I'm awake enough to want to face trying to dig stuff out. I suspect more refs are needed for big chunks of this too. Anyone up for a project? :-) Caomhin (talk) 21:12, 30 April 2008 (UTC)
Right, some extra reading. The Aircraft Engine Historical Society support the Castor Oil stuff in an article by Kimble D. McCutcheon http://www.enginehistory.org/Gnome%20Monosoupape.pdf (which actually includes third party reference too!) http://www.aviation-history.com/engines/rotary-theory.htm gets referenced in a few places too and they also claim the oil mist was enough to affect the pilots. Other sources seem to make no reference either way. It seems best to leave this logic open while more sources are gathered.
Throttle-wise. I believe the last edit makes the situation unclear. The article originally stated that the Gnome has no throttle which Chad Willie agrees with, the Gnome has a faux-throttle which killed certain cylinders. The very sources given to claim that "all" rotaries had a normal throttle states quite clearly this isn't true, as does every other source that is within easy reach. In fact the edit itself contradicts itself by then commenting on this cylinder shutdown replacing a standard throttle on some engines. It seems like violent agreement in logic but confusion over the ways of expressing the matter - a recipe for disaster :-) Basically it seems that this part simply needs tidying to use language which is slightly clearer.
Just a personal opinion Caomhin (talk) 21:54, 30 April 2008 (UTC)
1. The laxative effect! This actually looks VERY likely - Mr. Wille's comments notwithstanding. Just because the rotary engines he is responsible for haven't given him the "runs" doesn't mean they didn't give them to pilots "flying behind" engines subject to the varied loads of combat flying. In any case it is just one source against another. It just makes sense that sitting in a fine mist of half-burned castor oil in a 100 mile an hour split seam for an hour or two it would be hard not to end up swallowing a bit! (Perhaps someone needs to actually try???) I'm sure you could build up quite a pile of references in support of this (NOT all of them on the web).
2. The throttle question - of course only the monosoupape rotaries had NO throttle (except for ignition cutting). The others had have throttles, and this does need to made clear, although how immediate and precise throttle response was is another question. Genuinely contemporary sources do however refer to "blipping" when landing. Many wartime (1914-18) aerodromes were very small and confined indeed - others had narrow cinder runways because the grass surface was too soggy or otherwise unusable. These would have been plenty of motivation for pilots of the time to have used blipping for the same reasons modern pilots of vintage rotary-powered aircraft do. The "blip" switch (a little press button on top of the joy stick) was there to use!
3. The gyroscopic effect. This apparently was mainly effective in sharp turns, the nose used to kick up in a turn in one direction and down in the other. It was also much more marked on some types than others. The Camel was for instance notorious - whereas people habitually described the Pup as "delightful to fly". All this is actually quite consistent with Mr Wille's remarks - the torque in level flight probably wasn't THAT much more marked than other propeller aircraft - especially with the smaller rotaries.
Finally - yes you do have to watch out for hyperbole in sources on WW1 a/c - especially those originating in the period from about 1920 to 1960. Most of this is pretty easy to pick, however - what I call the "Boys Own Weekly" prose kicks in and you know you mustn't take anything too seriously. Soundofmusicals (talk) 01:19, 1 May 2008 (UTC)

On the laxative effect (not a very good band, by the way) - I'm not so certain that it was all that likely. Apart from Mr. Willes (who appears to be a pilot himself: http://stcroix.50webs.com/), the people at Rhinebeck Aerodrome, which has one of the largest collections of early aeroplanes in the world, have been restoring and flying WWI era aircraft with a variety of rotary engines (Gnome/Le Rhone/Oberursal, Clerget, Bentley, Siemens) for almost 50 years. One would think that they would have corrected the assertion Mr. Wille's makes on their website that the castor oil mist emanating from the engines does not "move the bowels." These people have first-hand experience flying aircraft with these engines. Consequently, they warrant a significant degree of credibility when discussing the characteristics of the engines.

Use of the blip-switch - the planes had them for a reason, and there's no reason they couldn't have been used by pilots then just as they are used today. Despite this, Mr. Wille clearly states in no uncertain terms that all rotaries, with the exception of the monosoupape, have two piece air/fuel throttles and that the factory manuals often emphasized the use of the throttle in lieu of the blip switch. He admittedly does not give line and verse of specific manuals on this point and does not provide pdfs of them in this article, but that would be asking a bit much.

—Preceding unsigned comment added by SonjaZ (talk • contribs) 04:26, 1 May 2008 (UTC)

I'm sure you'll all hate me but I've tried to clarify a bunch of stuff. If we could try to avoid any major edits which change the meaning without prior discussion for a little while I suspect that would help. If I've screwed something up badly then give me a poke and I'll happily try to fix it.
Re: laxative - I have to say that logic falls squarely on the idea that it was an issue. Maybe not on short flights and it's probably been exaggerated, but I suspect it was a factor. Mr. Wille is the only person to make reference to it not being an issue in my brief hunt, others either remain silent or say it was a problem. I suspect the silence is taste related. "Race with the Wind: How Air Racing Advanced Aviation" By Birch Matthews (ISBN:0760307296) describes a "laxative mist" on p130 although I think my favourite wording was "It is said that a pilot who spends many hours breathing unburned Castor oil never suffers from constipation." from http://www.ancientalley.com/ancient/rhinebck/gnome/gnome.htm
So yeah, I think it sounds reliable and that we can find sources to back it up. Maybe more are needed but a lone dissenting voice does not a true argument make. I've left it off for now though as I suspect we'll lean towards edit wars if this isn't agreed beforehand.
Caomhin (talk) 07:46, 1 May 2008 (UTC) (Off to find The Laxative Effect's awkward second album)

It's a decent point that some pilots may not have mentioned a laxative effect due to it being in poor taste and this makes it difficult to verify that the engines did or did not make one sick. However, the key difference in the documentation provided here is that of first-person testimony versus hearsay. Mr. Wille and the Old Rhinebeck organization, whose site is running the article which states these claims are popular myths, have a great deal of first-hand experience maintaining these engines and flying them in vintage aircraft. The stuff I read while growing up(as well as the documents cited here) which say it was a problem do not cite to any verifiable first-hand accounts or personal experience in support of their assertions. In short, to refute the first-hand evidence from Rhinebeck stating that the castor oil mist is not a problem and that all rotary engines have a throttle (including the monosoupape, though its throttle consists of a cylinder switch), the best evidence would be a first-hand account from a pilot of a rotary-powered aircraft who says he had a problem with the castor oil making him ill or that the engines didn't have a throttle. Second-hand accounts by people who never flew the aircraft are not as convincing as statements by people who have, no matter how many second-hand accounts there may be, and a falsehood stated repeatedly is no more true than when it was first told.

This is entirely speculative, but one would think that if a person were inhaling castor oil in such a quantity that enough of it was reaching their bowels to cause diarrhea, a person would also complain of serious respiratory problems due to the oil in their lungs.

I would also like to let it be known that if someone will fly me around in a two-seater powered by a rotary engine, I consent to be a guinea pig in the interest of wikipedia (but only on this point). SonjaZ (talk) 14:31, 1 May 2008 (UTC)

Sorry but Rhinebeck do not say that all rotaries have a throttle. "The exception" are the exact words used on that article, that is expressly saying that the Gnome doesn't have a throttle. And it should be noted that no other source appears to contradict this point. The cylinder cut-off trick isn't an actual throttle, merely a way to vary power delivery.
With regards to the laxative effect you'll also note the article makes no current statements about this. There is enough logic behind the comments that it is plausible there could potentially be some truth behind it. However everyone agrees the need for more reliable sources. There are a variety of sources that support the laxative argument however none of a high enough confidence to use. It should also be noted that Chad Wille alone doesn't not qualify as enough evidence. The argument in either direction needs multiple, concrete sources (i.e. pilots during the war) before anyone even considers reinstating this as a fact either either way. At absolute most we could have a reference to the fact that there is disagreement over the issue.
I think re-iterating these points gets us nowhere. Until anyone can find more sources that comment either way it's a largely dead issue.
Caomhin (talk) 20:02, 1 May 2008 (UTC)

The Rhinebeck site says:

"[W]hoever started the rumor that rotary engines are unthrottleable should be throttled! In fact, all rotaries have two piece air/fuel throttles that act very much like their modern single piece counterparts once they are understood. They allow single lever normal throttle response from idle to full speed and anywhere in between. The exception to this is the Gnome Monosoupape, which has a clever pilot controlled cockpit switch allowing it to run on 1, 3, 6, or all 9 cylinders giving a fine variation in power output, just like a throttle. "

It also states:

"It does throw a castor oil mist, leaving that wonderful smell many know from days of model airplane engines, but not enough to effect the pilot." http://www.oldrhinebeck.org/technical_corner_001.htm, accessed 2008-5-01.

SonjaZ (talk) 20:26, 1 May 2008 (UTC)

Sonja - I read the article. I read that section, I even quoted it in my last comment. "The exception" and "just like a throttle" (emphasis both mine) state clearly it is not an actual throttle. You're quoting something which explicitly disagrees with your argument. We all agree it gives the same abilities as a throttle, but it isn't technically a throttle. Now please stop talking to me like I'm an idiot and stop spamming that URL all over the shop, we know it exists. And I repeat, simply quoting Chad Wille again and again does not make him become multiple sources. We know he says it's not an issue, it's the main reason the article makes no comment either way right now. Please find another source to support his comments. Caomhin (talk) 20:38, 1 May 2008 (UTC)
A further point about the "selective cut out on a mono rotary - while the ignition to those cylinder was cut the fuel/oil mixture was not! So the use of the device just as if it were a throttle was asking for an engine fire!! Managing a rotary engine in flight was actually a good deal more complex and fiddly than a "stationary" engine, even a 1915 example of the species (I have a good "book" source on the problems that I will be rereading when I have a spare hour or two). I also own a vintage college engineering text on aero-engines that describes the old rotaries from a purely technical point of view that I will dig out.
The article (apart from the initial definition bit) is a horrible mess at the moment - and needs a COMPLETE rewrite - togther with references and subheadings to break up that great block of text. I think as a general rule when two or more more or less equally creditable sources diametrically disagree we need to take both into account. Even something like "while (source A) claims ... (source B) states...". I am planning to do this, if no one else jumps in first (please please...)
On blip switches - pupils were strongly discouraged from using the blip switch to turn off the ignition after landing - but to use the master switch on the dash instead (and yes, I have a source for that one too) but apparently almost no one used the throttle on a rotary for landing - it was just too fiddly (remember the mixture control had to be adjusted with the throttle itself), especially at a time when you were involved in the most difficult part of a normal flight, getting one of those hairy little machines to land without turning over. Soundofmusicals (talk) 23:41, 1 May 2008 (UTC)