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Revision as of 09:42, 30 June 2012 editAndy Dingley (talk | contribs)Autopatrolled, Extended confirmed users, Pending changes reviewers, Rollbackers160,200 edits →What the trade, manufacturers, experts etc call them← Previous edit Revision as of 12:52, 30 June 2012 edit undoBridge Boy (talk | contribs)1,682 edits →What the trade, manufacturers, experts etc call themNext edit →
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:::::* ''" 2 or 3 people who think they own motorcycle related topics"'' :::::* ''" 2 or 3 people who think they own motorcycle related topics"''
:::::: Why do you think this is a topic only about motorcycles? ] (]) 09:42, 30 June 2012 (UTC) :::::: Why do you think this is a topic only about motorcycles? ] (]) 09:42, 30 June 2012 (UTC)


::::::: A number of those sources, which you don't properly reference, are merely blogs or PR releases (primary sources) and so would fail "reliable sources", Dennis, but thank you for conceding parallel twin is the most common use as I suggested. However, the use of term inline is normally used to describe a sub-set of parallel twin engines where the crankshaft is inline with the chassis instead of across is. In short, an inline twin is a parallel twin but not all parallel twins are inline twins hence we cannot use inline, see below (e.g. you will references to "inline parallel twins").

::::::: No offence towards you intended at all Andy. We've never encountered each other before and you seem to be perfectly reasonable and polite. I am sorry if I was blunt to you. You are, of course, perfectly correct, the topic is not only about m/cs, however, it is pretty much only m/c and related product manufacturers that make and use parallel twins now and that is born out in the references. Believe me, I probably spent hours looking over references.

::::::: I actually expected to find more use of other terms but I did not, not even amongst small marine engines which was the only other area I could of think of where they are used, e.g. . It seems only a simple non-descriptive two- or twin-cylinder are the only other commonly used terms.

::::::: Yes, I agree I was expecting to find more references to inline twins and was surprised by the predominance of the term parallel. The use of the term inline is more commonly used as a reference to the relationship of the crankshaft to gearbox and drive rather than the engine itself. Longitudinal or tandem parallel twins (Sunbeam S7, Rotax 256, Kawasaki KR250 and marine engines) are far less common. Given that the policy states "consistency", if we look at the V-twin page, longitudinal V-twins occupy a subordinate position reflecting that relative rarity. Actually, there are probably enough sources to split both 'horizontal' and 'longitudinal' parallel twins and 'horizontal' and 'longitudinal' V-twins into separate topics, if someone could be bothered to write them

::::::: I cannot because I have had too much of time wasted by the stupidity and ignorance of having to question a choice as poor as "Straight-two engine", and all the bitch slapping and conniving that has ensued since. Something these people don't seem to realise detracts from the job at hand.


::::::: I have had run ins with some of these other bods before and can see the psychology and the games that are being play. I find it tiresome and counterproductive to engendering voluntary cooperation in this project, and beyond what I consider to be reasonable. The system appears to defend ignorance and reward irrationality if expressed in the terms of various policies, and benefit those with a willingness and knowledge of who and where to rat on others.

::::::: I have no idea why Dennis has fixated on me and was working up such a case, because he is obviously otherwise well informed and intelligent. Yes, I challenged his knowledge or prejudices in other areas but I don't see that as a good enough reason to be "punished" by him, or have him build up "bad marks" against me, often very falsely. He came out with strong statements elsewhere that led me to question his judgement.

::::::: Of course, people do use the internet to behave in a manner towards other people that they would never do or get away with in real life. Perhaps it is just an unconscious ]? --] (]) 12:52, 30 June 2012 (UTC)

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I changed the entry to reflect the fact that a parallel twin is NOT equivalent to a straight two. I have updated this and other articles to remain consistent with the original assertion that "straight twin" is not equivalent to "straight two" but rather means there is a common crank pin (ie making it equivalent to the true meaning of parallel twin), although I don't know whether this is true or not 220.237.161.186 14:21, 24 September 2007 (UTC)snaxalotl

And what documented evidence of this convention do you have? Respectfully, SamBlob (talk) 00:04, 27 November 2008 (UTC)

Surely not

Current article reads the left cylinder fires, then 180° later the right cylinder fires, then the engine rotates 360° before the left cylinder again fires. Ummm, you could split hairs and argue that this is true, the engine does rotate 360° before the left cylinder fires, but it then rotates another 180° before the left cyinder finally fires... 540° in all. Andrewa (talk) 07:47, 9 February 2009 (UTC)

Big Bang

The supposed firing sequence of the 270° twin is not "big bang", since it's 270° between ignitions, then 450 degrees of "rest" - that is in order to get the compromised smoother firing than a 180° crank (180°-540°), but less smooth than a 360° crank (360°-360°). Firing 90°-630° would be considered big bang, but it is unknown (to me) whether any engine actually does this, and would barely be more refined than a single.

As for the 2009+ Yamaha R1, that, too, does not use a big bang firing sequence. It is 90°-180°-270°-180°, like one bank of a cross plane V8, or identical to a 90° V4 (e.g. Honda VFR 800). Yamaha have expressly stated that they no longer believe "big bang" to be beneficial now that they have eliminated the oscillating inertial torque resulting from the periodic kinetic energy exchange between the crankshaft and pistons. See this article, and this one.

--Identiti crisis (talk) 23:04, 21 April 2011 (UTC)

Any discussion of the supposed traction / "power delivery" advantages with the 270° crank, if indeed due solely to the uneven firing interval, would surely also apply to the 180° crank, given that is more uneven; similarly, it would apply equally to a 90-degree V-Twin, as that has exactly the same inertial torque characteristics and power stroke timing. Presumably, the "power delivery" is "improved" with the 270° crank for much the same reason it was with the R1 above, simply by significantly reducing the oscillating torque resulting from kinetic energy exchange between the rotating and reciprocating parts ("inertial torque"), a characteristic it would share with the 90° V-Twin.

--Identiti crisis (talk) 12:34, 20 October 2011 (UTC)

What exactly is a parallel twin?

I have now twice tried to imply in the article something I think it ought to contain, which is the fact that some people believe that there are TWO kinds of inline twin engines,(not counting the newer 270° variant) which is the PARALLEL and the VERTICAL twin. These designations describe the positions of the crank pins rather than the placement of the cylinders. Some "experts" stubbornly state that the placement of the crank pins has nothing to do with (the origin of) these terms, but that the term "parallel twin" exclusively means that the cylinders are placed in the same parallel plane, as opposed to in a V-engine, and that "vertical twin" exclusively means merely that the cylinders are placed vertical as opposed to inclined. I find that nonsense! In case you mean the latter is true, I ask you: Why are there no such terms on engines with other cylinder numbers, where they should be fully applicable as well? And why is there no such thing as a "horizontal twin" when there is a vertical one in existence? Ever heard of a "Vertical single" or "Parallel four" used as a term? Hardly, even though they are fully existent. I have no particular "reliable source" on that my explanation is the correct one, other than articles I have read that clearly states that it is the case, without giving any "reliable source" on the origin of the term. Try to google "vertikaltwin" in Swedish pages and tell me what you find. I also read an article in Norwegian about the Jawa OHC 500, which normally was a "Vertical twin" (after my explanation), but kits for racing were available, with 360° crank and different camshaft thus making it a parallel twin. I did not read this on the net, but if I found it, could it be regarded as a "reliable source"? Can my old teacher, that was an old motorcycles nut, be regarded as a "reliable source"? He explained me the difference of a parallel and a vertical twin and why they are called so. Unfortuneately he is dead now, so I'm the only one left to tell what he told me. Does that make me a "reliable source"? Hardly, but those who advocate the other explanation does not have any reliable sources either. The truth is that there are no reliable sources on the term, only different opinions. But I think the article should contain my explanation as well, as opposed to only the other one, as it clearly seems to be two different explanations present.(and since Swedish sources exclusively use my version.) I therefore think my first version that stated that SOME SOURCES(e.g. all information in Swedish) claim that this is what the terms Vertical and Parallel twin is about. If you read on the top of this very page there is another contributor which has about the same explanation for the "True meaning of Parallel twin. Which should about state my case. Which is, that if the article cant contain both explanations, it should not contain any of them.

Arve Kvalvik — Preceding unsigned comment added by 88.84.36.158 (talk) 13:35, 25 October 2011 (UTC)

Sorry, but in WIkipedia truth is trumped by verifiability. Whatever you put in the article, without sources, is original research and therefore doesn't belong (see WP:RS). From my perspective I have seen the term used for 180, 270 and 360 degree configurations as a generic term for how the cylinders are arranged in relation to each other e.g. at Totalmotorcycle.com, at MCN, at Howstuffworks.com, by Yamaha for their 270 degree XT1200Z, etc. This book explicitly states that parallel twins can have any crankpin alignment. Similarly you can find references that use the term vertical twin to refer to engines with the 180 or 360 alignment. Try as I might I could not find a single reference that supports your assertion that parallel is 360 and vertical is 180. Most references to vertical are simply that the cylinders are aligned vertically, rather than at an angle (as they are on the BMW F800 bikes) --Biker Biker (talk) 19:00, 25 October 2011 (UTC)

Ok, take a look here: http://translate.google.com/translate?sl=sv&tl=en&js=n&prev=_t&hl=no&ie=UTF-8&layout=2&eotf=1&u=http%3A%2F%2Fmetrobloggen.se%2Fmotorblogg%2Fhonda_cb_450%2F

And here: http://translate.google.com/translate?sl=sv&tl=en&js=n&prev=_t&hl=no&ie=UTF-8&layout=2&eotf=1&u=http%3A%2F%2Fwww.classicmotor.se%2Fartiklar%2Fexperten%2F20090331%2Fhur-arbetar-en-vertikaltwin%2F%3Fpage%3D1

As you can see in the last article there is a full article on the subject in Classic Motor no. 10/1991. Is that a "verifiable source" enough to you, like that book of yours? Those who wrote them are anyway in both cases only people. My guess regarding the explanation of the terms in your books is that the authors or their source knew about these much used terms, but not really what they meant, so they stated in their scripts that they meant the most obvious they could think of. Like it has been forgotten with time so to speak. The version in the current article was even another new one, that "parallel twin" is cases where the crank sits across the frame, longtitudal ones is only an inline twin. As far as I know the term "parallel" means something very close to "in line with" so how the author figured that one I can only wonder. Anyway as you can see from these articles, there are more people that uses my explanation of the terms, so now you know that I'm not taking it out of the blue. My suggestions are to either write in the article that there is more than one explanation on the subjects vertical and parallel twin, or to simply only write that they are terms that are often used when talking of two cylinder motorcycle engines, leaving any further explanation out.

AK — Preceding unsigned comment added by 88.84.36.158 (talk) 00:25, 26 October 2011 (UTC)

Move discussion: Straight-two engine or Parallel-twin engine?

This article, Straight-two engine had been cut and pasted into the redirect Parallel-twin engine. Since the cut-and-paste move was done in such a way as to obscure the edit histories of the article and the talk page, which is unacceptable to Misplaced Pages as it violates the CC-BY-SA 3.0 License and the GNU Free Documentation License under which Misplaced Pages operates, it has been reverted.

However, the action does bring up a point. Is "straight-two engine" the best name for this article? Does it follow the naming guidelines of Misplaced Pages? It is probably best to discuss this and come up with an established consensus on what the name of the article should be.

Sincerely, SamBlob (talk) 18:44, 16 June 2012 (UTC)

The move was not done "in such a way as to obscure the edit histories". The move was done in good faith, and based on the expert knowledge of the reliable sources, by a beginner at this game who was trying his best to help and you've created a tangle of related short-cuts and talk pages now.
By all means, please work out how to transfer the page "properly" but in the meanwhile learn to speak to willing volunteers in a way likely to engender their cooperation.
Straight two? If you don't know anything about engines, try starting with Google Books or Scholar.
In the future, try approaching someone new politely and ask them, "Can I help you? What exactly was it you were trying to do?" etc instead of accusing them. You will find it elicits a far more civil response, and then you will be able to judge their intention. --Bridge Boy (talk) 00:42, 28 June 2012 (UTC)
I'd like to keep it the way it is until we can straighten out the edit histories. One might be slightly more common than the other, but I don't see a compelling reason to clobber the history over semantics. --Dennis Bratland (talk) 01:01, 28 June 2012 (UTC)
OK, I think I've sort out the tangle of all the related short cuts and have the discuss in the same place. Please don't mess with it until we resolve this issue.
As fas as I am concerned, the argument for "Parallel twin" over "Straight two" is clear.
I followed the style of other engine configurations to include the hyphenation, although I have no strong position in support of that, and tidied up many of the rest of them so that they all matched, there were obvious shortcuts, and there was some sense of logical consistency.
I suggest any changes should be conceived of in consideration of the bigger picture.
Daniel, stop your gaming. My comment to you was not "vandalism". Please learn to speak to people with civility, approach them first to see what it is they are doing and understand what is going on, try offering help before you accuse them, especially dishonesty or with prejudice. --Bridge Boy (talk) 01:28, 28 June 2012 (UTC)
O.K., since you will not go to WP:MOVE and read why you should not do this, let me bring the relevant part of WP:MOVE to you:
Please do not move or rename a page by copying/pasting its content, because doing so fragments the edit history. (Misplaced Pages's copyright license requires acknowledgement of all contributors, and editors continue to hold copyright on their contributions unless they specifically give up this right. Hence it is required that edit histories be preserved for all major contributions until the normal copyright expires.) - from WP:MOVE
I will now ask an administrator to try to undo the tangle you have created.
Sincerely, SamBlob (talk) 01:40, 28 June 2012 (UTC)


  • Sorry for coming to this so late, but isn't this a case for splitting? Straight twos are a fairly humdrum entry in the inevitable list of basic engine configs. They're found everywhere. Parallel twins though are a narrow, albeit well-populated, subset of this. They imply a timing that just isn't used for the other straight twos. The term is also, IMHE, only applied to motorbikes.
Parallel twin warrants its own article, under that title. Yet we certainly can't rename straight-two to it, as that would be way inaccurate for the others. Andy Dingley (talk) 10:48, 28 June 2012 (UTC)
Can you give us any references or citations to differentiate the two, and clarify what precisely you are talking about? I'm finding it difficult to find any reference to "straight-two" at all, except those referencing the Misplaced Pages. On the other hand, I can find plenty that use parallel twin for 180, 270 or 360 degree twins, and referred to it as "most commonly known". If you read the references I gave, you will also see it is widely used for automobiles, snowmobiles, ATV, jet skis and so on, and has been for decades.
Even if you cannot provide references, I'd genuinely like to know where and from when the term was used. (What I think you are suggesting is that parallel-twin is used only for 360 degree engines but that is just not so). --Bridge Boy (talk) 11:47, 28 June 2012 (UTC)
  • This bit of the article has not only survived B-Boy's editing blitz but seems to have actually gained a reference from it:

"Parallel twin" refers to an engine which has its crankshaft mounted transversely across the frame; and the term "inline twin" refers to exclusively to an engine with its crankshaft mounted inline with the frame, such as the Sunbeam S7. - from Straight-two engine#Motorcycle use

If this is to be believed, then the term "parallel-twin" is specific to straight-twins that are mounted transversely in the frames of motorcycles. Therefore, the more general term, "straight-twin", should be the title of the article.
Sincerely, SamBlob (talk) 12:56, 28 June 2012 (UTC)
Apparently, this is not a "parallel-twin" but an "inline twin".
Here's a reference for "parallel-twin"... that goes against it being the general term because it reinforces that the term is a specific case:

"parallel twin A two-cylinder engine layout in which both cylinders are side by side and mounted across the frame" – Wilson, Hugo (1995). "Glossary". The Encyclopedia of the Motorcycle (in UK English). London: Dorling Kindersley. p. 310. ISBN 0-7513-0206-6.{{cite book}}: CS1 maint: unrecognized language (link)

I maintain that "straight-twin" is a more general term describing all engines with two cylinders in line with each other on a common bank, whether the cylinders are across the frame ("parallel"), along the frame ("inline") or not in a motorcycle at all. Sincerely, SamBlob (talk) 00:24, 30 June 2012 (UTC)
That's a compelling argument, and with more sources saying the same thing, I'd be convinced. It might have been an important distinction in the past, but in my list of quotes below, I have a large number of cases in motorcycling books and magazines where they treat inline and parallel as interchangeable. In almost every instance of "inline twin", they're referring to a bike like the BMW F800, with a transverse crankshaft. It does, however, strongly undermine the idea that "parallel twin" is the only true and correct term. Sources have been found for every variant term, and the only question for the page move is which one is most common. For the article content, they all should be mentioned. --Dennis Bratland (talk) 03:46, 30 June 2012 (UTC)

I find the editing blitz - specifically the repeated insertion of the term "parallel twin" into the article - to be somewhat tendentious editing and rather WP:POINTy. For now I have reverted the multiple additions of the term following further discussion. Last night's clumsy work followed by today's blitz do little to help an editor to win favour with others. --Biker Biker (talk) 19:23, 28 June 2012 (UTC)

Votes


Could people actually sustain their positions using references because I realise I snubbed enough noses for people to just vote against whatever is being propose rather than depend on what the sources say?
I added 35 references from reliable sources at the top of Google to support parallel-twin. I don't see any of you doing the same work. Unless you can, I think any decision going against that will merely illustrate that you are acting out of person prejudices rather than common sense or knowledge of the subject.
I spent quite a while looking at this and could not find any good sources to support straight-two at all which underlines the ridiculousness of all this. Whilst you're willing to play the game with policies, not one of you is standing to defend straight-two, developing the article, nor even reading the references given. Look out there in the real world, there is a clear preponderance to parallel-twin. There could be an argument for splitting off inline-twin (e.g. like a Sunbeam) if someone is willing to do the work but I think it would be wrong to confuse them with V-twin Sam ... unless you have any strong sources to support that use. In such an application it would generally be an "inline V twin-engine" to differentiate from an inline parallel-twin engine. Correct me if I am wrong.
I'll do a breakdown of current manufacturers over the next day or so, so as to establish the most current common usage. In the meanwhile, I encourage you to survey Google Books to gain an impression of the most common use of the term "straight twin". Straight-twin engine does not score any higher, although it is "straighter"
Can anyone come up with where the current term actually came from and where is used apart from here? If not, can we remove it immediately? Thanks --Bridge Boy (talk) 05:11, 29 June 2012 (UTC)

Commons

See also http://commons.wikimedia.org/Special:Contributions/Bridge_Boy Andy Dingley (talk) 16:00, 28 June 2012 (UTC)

Request page history merge

{{Histmerge|Straight-two engine}} Sincerely, SamBlob (talk) 01:47, 28 June 2012 (UTC)

Moved back

Moved back... I think. I'm not sure which page it was at originally. Let me know if I made a mistake fixing the cut-and-paste move. NW (Talk) 02:05, 28 June 2012 (UTC)

This is right. I've requested comments from WikiProjects Motorcycling and Automobiles to see where the consensus is. Thanks! --Dennis Bratland (talk) 02:09, 28 June 2012 (UTC)
Yes, you made a mistake. All Sam asked for was a history merge, not a page moving. The topic and talk page should be at Parallel-twin engine. --Bridge Boy (talk) 06:27, 28 June 2012 (UTC)
It is as it was. Discussion will (hopefully) bring consensus as to where it should be, at which time it will be put there. Sincerely, SamBlob (talk) 12:23, 28 June 2012 (UTC)
If this page is titled what it was a month ago, I'm satisfied. The move discussion above should establish a new firmer consensus. NW (Talk) 12:37, 28 June 2012 (UTC)
Do you know anything about engines? Can you supply any references to support the predominance of the term straight-two? Thank you. --Bridge Boy (talk) 12:49, 28 June 2012 (UTC)
I will try to explain this to you: The page has been brought back to where it *was*. Where the page *will be* depends on the outcome of the above discussion. Until the above discussion is concluded, the page will remain where it *was*, regardless of where anyone, including you or I, thinks it should be. Do you understand this? Sincerely, SamBlob (talk) 14:06, 28 June 2012 (UTC)
There is no point in feeding this troll any longer. He doesn't listen. --Dennis Bratland (talk) 15:11, 28 June 2012 (UTC)
A troll? No, he is not a troll. I'm pretty sure he is upset because he is a bit new. Don't bite the newcomers. --J (t) 00:22, 29 June 2012 (UTC)
He's not that new. There have been repeated discussions where he simply doesn't care to listen to other editors. For example, numerous requests to not leave all his edit summaries blank. He's been told at least a half dozen times by different editors that the problem here is that this page was moved incorrectly, and his response is "do you know anything about engines?" He's repeatedly been asked to supply sources for his POV-pushing edits, and all he offers is bluster. For example, do you see one single source cited to support the move to "parallel-twin engine"? None. Just bluffs about sources that we never see. And then there was this.

It's like talking to a brick wall. Someone whose comments are not constructive, and only serve to draw out pointless replies, and who does not respect the collaborative editing process, is a troll. --Dennis Bratland (talk) 00:35, 29 June 2012 (UTC)

Just the sort of answer I would have expect from you Dennis, and precisely the same manner and attitude others users have complained about you too.
Half a dozen times?
Prove it. I see one, and it's from you. You are trying to prejudice others against me, here and on my talk page, with falsehoods.
The problem was, Dennis, you "told me". You did not "ask me". You did not politely explain why or show me as a newcomer. My response, at that time, was your attitude, and you need to modify it. I inferred that "you were not paying me", so don't speak to me as if you are my boss. This isn't your website.
I'll respond to anyone that approaches me reasonably and intelligently in a reasonably and intelligent manner, but what you are doing is gaming, as with your misrepresentation and little "tell-tale" above. I read your talk page and elsewhere. You have a history of doing this to others.
FYI, I added 35 references to the article. How many did you check and how many did you add?
I encourage others to check the other articles I have worked on and again you will find a very high proportion of edits with good references, so please allow me to politely call BS on this one and let's all move on.
If you all care so much about policy, what offends me, as someone who does know a little about engines, is the ridiculousness of the title of this topic. Despite all the quibbling, not one of you has been able to support it with references, how absurd is that? All someone had to do was merge the history, one person one click. It's SamBlob you should be pissed at, not me. --Bridge Boy (talk) 05:40, 29 June 2012 (UTC)

What the trade, manufacturers, experts etc call them

OK, as promised. With links to the international websites where possible. This is what the trade and manufacturers call them.

If you disagree with the use of parallel-twin, please provide your evidence or otherwise justify your opinion.

If I have missed out any important reference, please correct the list.

Thank you. --Bridge Boy (talk) 07:44, 29 June 2012 (UTC)

BTW, for each of these searches I did two searches; one for "parallel twin" and one for "straight twin", using Google to search the site, e.g. site:xxx.com. In every case, one or more variation of parallel twin came up and none for straight twin. --Bridge Boy (talk) 01:56, 30 June 2012 (UTC)
Source Terms used Alternative? URL
* Honda parallel-twin, parallel- twin engine, parallel twin-cylinder engine Straight twin - zero bit.ly/LkrxDz
* Kawasaki parallel-twin, parallel twin, parallel-twin engine, parallel twin cylinder engine Straight twin - zero bit.ly/LyTEgz
* Yamaha parallel twin, parallel twin engine Straight twin - zero bit.ly/METfxN
* Suzuki parallel twin, parallel twin-cylinder Straight twin - zero bit.ly/NURI71
* BMW parallel-twin, parallel twin engine Straight twin - zero bit.ly/LyVMoL
* Triumph parallel-twin, parallel-twin engine, parallel twin Straight twin - zero bit.ly/MbkkKv
* Norton parallel twin Straight twin - zero bit.ly/LUWhfk
* Polaris parallel twin Straight twin - zero bit.ly/KH9Tbz
* Ducati parallel twin-cylinder, parallel twin Straight twin - zero bit.ly/LIbUKY
* Husqvarna parallel-twin Straight twin - zero bit.ly/MDxKMx
* Motorcycle News parallel-twin, parallel-twin-engine, parallel twin Straight twin - zero bit.ly/OGZjsq
* Motorcycle parallel-twin engine, parallel-twin, parallel Twin Straight twin - zero bit.ly/N2spPC
* Cycle World parallel-twin Straight twin - zero bit.ly/LIcMPH
* National Motorcycle Museum parallel twin engine, parallel twin Straight twin - zero bit.ly/Qxrmb4
* AMA parallel-twin engine, parallel twin, parallel twin engine Straight twin - zero bit.ly/LUYN5r
* DOT parallel twin Straight twin - zero dot.gov
* Nat. Museum Motorcycling, Aus parallel twin Straight twin - zero bit.ly/L71fJB
* International Motorcycle Show parallel-twin, parallel twin Straight twin - zero bit.ly/NJbBdL
* Cycle Trader (181,000 bikes for sale) parallel-twin, parallel twin, parallel twin-cylinder Straight twin - zero Link
* Ebay parallel twin Straight twin - zero

Do I really have to go on? Oh, why not ...

The trouble is that they're all motorbikes - the term parallel twin is used around motorbikes, there's little question of that. However two cylinder engines have broader uses than that. Can you show any use of "parallel twin" in a non motorbike context? Andy Dingley (talk) 09:42, 29 June 2012 (UTC)
Polaris isn't. Please read the references already given on the topic. I am sorry Andy, I've done my work and all I have to prove is a reasonable preponderance, not document every case. If anyone can better it in other areas, please do. Otherwise it's a a ridiculously clear slam dunk.
I've added plenty of references regarding cars to the article itself, e.g. NSU related, John Deere. It's the same again. Parallel twin.
But I am looking forward to seeing how the other motorcyclists enthusiasts argue otherwise. It'll be good for a laugh. I tried. There are basically no references to back alternatives up.
Thank you. --Bridge Boy (talk) 10:39, 29 June 2012 (UTC)
Again, so what? No-one is disputing that parallel twin is in use (there's some question as to just how broadly). Your assertion though is that this is the only name used for any two cylinder inline engine, and so the article should be renamed throughout. Go back to pre-war diesels and the Junkers HK series - you won't find those described as parallel twins. Look at half a century of medium-sized stationary and boat engines with two cylinders inline. The "parallel twin" designation just isn't used here.
What's the most common (only common?) two cylinder car engine at present, the Fiat TwinAir. Now find a decent source describing that as a parallel twin and you'll see that it's also a 360°, with a balance shaft. A parallel twin, but just that type of engine that is (I think generally) agreed to be the classic "parallel twin", balance problems and all. Hard to find a god picture online, but try this
Are there any two-strokes ever described as parallel twins?
Of the four strokes, how many are 360° apart? Looking back at '50s & '60s motorcycles, what's the relation between the "parallel twin" designation, and it being reserved for 360° four strokes, even if this has blurred since?
There's also the issue that you appear to be citing eBay as a source, and others no more credible. That's the "billion flies" argument. Of course there are "sites on the web" that will call anything anything, but that doesn't mean they're correct to do so. Andy Dingley (talk) 12:10, 29 June 2012 (UTC)
Yes, if you read the references you will find two-strokes named as parallel-twins, e.g. Japanese Grand Prix Racing Motorcycles. Mick Walker. Redline Books, 2002.
No, I did not assert it is the "only". I assert that it is the predominately Recognizable, Natural, Precise, Concise and Consistent title inline with Misplaced Pages title naming policy.
I have presented a balance of evidence that it is impossible to argue against honestly. Way beyond what is necessary.
Neither you, nor anyone else, are offering any alternative reliable sources at all. Nor the greater balance of evidence to counter my position which you now need to. The fact is, you cannot. I've looked. (And, as it is general and not specific topic, the Misplaced Pages is not bound by what an engine may or may not have been called in the Victorian or Edwardian period).
I am sorry but by having to latch onto and exaggerate the very final of 64 fair to excellent new references in order to establish any weakness to my argument, you've damaged the credibility of your opposition. There is no onus on me to do any more work.
If the alternative titles were in anyway common one would have expected to see evidence of it all over the place. They are not and the fact that you are all willing to sit there, dig your heels in and argue because WP:IDONTLIKEIT instead of go and add reference to a topic such as Straight engine that had none until I add ones says it all really.
So what is this really about? WP:IDONTLIKEIT, or a little gang of 2 or 3 people who think they own motorcycle related topics (and I am not including you in that statement) not liking someone new on their block?
Show us your references. --Bridge Boy (talk) 17:31, 29 June 2012 (UTC)
List of refs for straight-two, inline-twin, straight-twin, etc
  • Crouse, William H. and Anglin, Donald L. Motorcycle Mechanics. McGraw Hill. ISBN 0-07-014781-7. 1982. p. 19-20. "Engine classification by number of cylinders… 2 in-line, v-2, flat-2…Two cylinder engines are called twins. The two cylinder can be arranged in line (a vertical twin) or in a V, or opposed…"
  • The original Subaru vs. Mitsubishi faceoff. Import Tuner. 134 (May 2010): p16. ""1958 SPECS SUBARU 360 … LAYOUT STRAIGHT TWIN"
  • "They can't all be GTOs." Motor Trend Oct. 2007: 118. General OneFile. Web. 29 June 2012. "Not everything Ferrari touches turns to blazing scarlet. In 1955, for instance, engineer Aurelio Lampredi--working with Enzo and son Dino--creates an experimental inline-two-cylinder F1 engine (the theory being that two large cylinders would provide enormous torque for tight circuits like Monaco). "
  • Husick, Chuck. "Rally Round The Outboard." Yachting Mar. 2007: 118. General OneFile. Web. 29 June 2012. "The choices in outboard power include 11 models in Bombardier's Evinrude's E-TEC series; inline, two- and three-cylinder units ranging in power from two to 75 hp, a 60-degree, 115 hp V-4, and 60- and 90-degree V6s from 150 to 250 hp." :::::*note the sentence parallelism as the reason for this construction"
  • "Emission-compliant diesel engines cover 83 to 1,350 bhp in 10 models." Oil, Gas, & Petrochem Equipment May 2006: 18. General OneFile. Web. 29 June 2012. "Cat petroleum diesels line includes eight inline two, three, and four-cylinder engines with such features as single-side service access, 500-hr oil change intervals, compact injection pump timing devices, closed circuit breathers, improved governing systems, optimized injectors, and very low idle noise levels.
  • Watanabe, Laurie. "That magnificent man on his riding machines." Dealernews Nov. 1996: 26+. General OneFile. Web. 29 June 2012. "If you press him, though, Jim is likely to expound on his 1947 S7 Sunbeam - "twin-cylinder, rubber-mounted engine. They were an inline two-cylinder, not crosswise in the frame, like conventional twins are. It's like new, because it's been in a museum all its life.""
  • Tata Motors Limited Files Patent Application for a Novel Inline Two Cylinder Multi Point Fuel Injection Four-Stroke Reciprocating Piston Internal Combustion Naturally Aspirated or Turbocharged or Turbocharged Intercooled Spark Ignition Engine. "...application for a novel inline two cylinder multi point
  • Preview Tata Motors Limited Files Patent Application for a Novel Inline Two Cylinder Direct Injection High Pressure Common Rail Four-Stroke Reciprocating Piston Internal Combustion Turbocharged Diesel Engine. Indian Patents News 17 Dec 2010. "…application for a novel inline two cylinder direct injection"
  • SUSAN CARPENTER / THROTTLE JOCKEY; Bike 101: Choosing your ride; Don't be intimidated. These four motorcycles are geared for beginners.: Carpenter, Susan. Los Angeles Times 10 Jan 2007: G.1. "A high-revving, inline twin with four valves per cylinder, the 250R isn't especially torque-y, which is why it's great for beginners. "
  • PSA fires up two-cylinder turbo. Anonymous. Automotive Engineer33. 9 (Oct 2008): 5. "…baseline, it selected the inline-twin configuration as offering"
  • AMERICAN BEEMER Edwards, David. Cycle World 46. 12 (Dec 2007): 73. "...inline-Twin engine. With no racing pretensions, Wood initially had a problem..."
  • Steaming into the future... Barnett, Colin. Commercial Motor 209. 5322 (Mar 12, 2009): 44-45. "…will use the latest 800cc inline twin, which is much more compact"
  • Cruiser comparison: Kawasaki Vulcan 500, Anonymous. Cycle World 33. 2 (Feb 1994): 47. "…V-Twin class, so the little inline-Twin Vulcan doesn't exactly fit"
  • Toontown twin. Thompson, Jon F. Cycle World 34. 11 (Nov 1995): 44. "…rubber-mounted, sohc, 487cc inline-Twin, was the result."
  • Océ ColorStream 3500. Severs, Jon. Printweek (Dec 17, 2010): 16-17. "...configurations, so as a single unit, inline Twin or L-, H- or U-Twin for simplex"
  • Tuttle, Mark, Jr. "BMW F800S." Rider Dec. 2005: 15. General OneFile. Web. 29 June 2012. "BMW will tackle the middleweight market in the late spring/early summer of 2006 with a new F800S sport tourer, powered by the first inline twin-cylinder engine in BMW's history. The 800cc parallel-twin is produced in cooperation with Bombardier-Rotax…"
  • Miller, Nancy. "Highway stars." Wired Nov. 2007. General OneFile. Web. 29 June 2012. The $6,300 Aprilia Scarabeo 500 i.e. glides at 80 mph on freeway and still can zig-zag through street traffic. The Vespa GTS 250 sells for $5,999 and weighs 300 pounds but delivers a top speed of 76 mph. The Honda SIlver Wing sells for $7,999 and can easily top 100 mph with its inline twin engine.
  • "BMW AG adds scooter to 2012 range." Auto Business News 9 Dec. 2011. General OneFile. Web. 29 June 2012. The new scooters are to be equipped with a 647-cc inline twin cylinder engine that delivers 60bhp and reaches a top speed of around 100 miles per hour.
  • "MZ introduces third 1000cc unit." Powersports Business 16 May 2005: 30. General OneFile. Web. 29 June 2012. In fact, the frame and fairing of the Super Traveller are to a large extent identical to the MZ 1000 S that has been produced at the Zschopau factory since 2004. And, the four-stroke inline twin engine is identical with the MZ 1000 SF. The engine puts out 113hp at 9000 rpm.
  • Harrisonburg Daily News Record - June 2, 1989, Harrisonburg, Virginia. Kawasaki Motors Corp., U.S.A. (advertisement) "Like an 8-valve, in-line twin engine with 454cc's of torque and mid-range punch." --Dennis Bratland (talk) 19:17, 29 June 2012 (UTC)
  • Mick Walker's European Racing Motorcycles Mick Walker. Redline Books, 2000. ISBN 9780953131136. p.20 "the Rotax 256 inline twin would not be produced." p.25 "Rotax 256 inline twin… the Model 256 inline twin designed by…" p. 26 "Rotax 256 inline twin-engined Armstrong…" p. 28 "…Armstrong's version of the Rotax inline twin. "
  • Italian Racing Motorcycles Mick Walker. Redline Books, 2000. ISBN 9780953131112. p. 25 "Aprilia had seen how the inline twin cylinder two-stroke disc valve Rotax engine had performed…" p. 27 "…since the introduction of the old inline twin back in 1985…"
  • Popular Mechanics - Feb 1989 - Page 109. Vol. 166, No. 2 - 136 pages - Magazine "Also new from Suzuki are the inline twin 15 and the inline 3-cylinder 25. Both are equipped with loop- charging, oil injection and external- mount tilt and trim. The 25 also has pre-atomized oil injection and an overrev limiter."
  • American Motorcyclist - Dec 1990 - Page 47. Vol. 44, No. 12 - 60 pages. "… its spirited 248cc four-stroke inline twin engine, with twin cams and four valves per cylinder."
  • 365 Motorcycles You Must Ride - Page 43 and 44. Dain Gingerelli, Charles Everitt, James Manning Michels - 2011 - 320 pages "OHV, two-valve-per-cylinder, four-stroke, inline twin Horsepower: 51"
  • The Motor: Volumes 133-134; Volumes 133-134. 1968 "The Fellow 360 is an all independently sprung car with a watercooled 2- stroke inline twin at front driving the rear wheels via a 4-speed gearbox, in normal tune, it is a pleasant runabout. And now Daihatsu have added an SS version, …"
  • Antique Cars. Lord Montagu, Lord Montagu - 1985 - 80 pages -"The V-twin gave way to an inline twin, still made under Daimler license"
  • Snowmobile Service Manual Intertec Publishing - 1986 - 488 pages"Engines consist of two types; the axial fan, inline twin and the simultaneous firing opposed twin. "
  • Automobile quarterly: Volume 29, Issue 1. Princeton Institute for Historic Research - 1991 - "Note the incredibly narrow angle that makes the unit appear more like an inline twin than a V4. one."
  • Automotive engineering: Volume 102, Issues 1-6. Society of Automotive Engineers - 1994 "... and an outright miser working with two cylinders with somehow motorcycle-like inline twin thumps."
  • Classic Cars: 50 Years of the World's Finest Automotive Design. Brazendale - 1983 - 368 pages "They were vee-twin-cylinder engines designed by Daimler, which were replaced by the inline, twin-cylinder unit as used in the Phonix of 1 895."
  • Ultralight aircraft Michael A. Markowski - 1982 - 320 pages - "The Cuyuna 430-D is an inline twin cylinder of 30 hp."
  • Machine Design: Volume 54, Issues 1-6; Volume 54, Issues 1-6 1982 "A modified snowmobile power plant, the 30-hp inline twin has been detuned by lowering the compression ratio and modifying the carburetion"
  • Antique cars Michael Sedgwick, 1980 - 93 pages "The engine, an inline twin, lived in a box like a meat-safe at the rear."
I think it's notable here that so many of these sources are motorcycle-related. The use of 'inline twin' is not uncommon. It's also notable how many of them, like Mick Walker, are British. DK is German, and I wonder if the use of "straight two" isn't influenced by that language. Not that it matters how something got into English. It's here now.

Parallel twin is probably the dominant term, and the page should probably be moved there. But expunging all other variants, particularly inline twin, but also straight two and inline two, is not justified. --Dennis Bratland (talk) 21:14, 29 June 2012 (UTC)

  • " 2 or 3 people who think they own motorcycle related topics"
Why do you think this is a topic only about motorcycles? Andy Dingley (talk) 09:42, 30 June 2012 (UTC)


A number of those sources, which you don't properly reference, are merely blogs or PR releases (primary sources) and so would fail "reliable sources", Dennis, but thank you for conceding parallel twin is the most common use as I suggested. However, the use of term inline is normally used to describe a sub-set of parallel twin engines where the crankshaft is inline with the chassis instead of across is. In short, an inline twin is a parallel twin but not all parallel twins are inline twins hence we cannot use inline, see below (e.g. you will references to "inline parallel twins").
No offence towards you intended at all Andy. We've never encountered each other before and you seem to be perfectly reasonable and polite. I am sorry if I was blunt to you. You are, of course, perfectly correct, the topic is not only about m/cs, however, it is pretty much only m/c and related product manufacturers that make and use parallel twins now and that is born out in the references. Believe me, I probably spent hours looking over references.
I actually expected to find more use of other terms but I did not, not even amongst small marine engines which was the only other area I could of think of where they are used, e.g. . It seems only a simple non-descriptive two- or twin-cylinder are the only other commonly used terms.
Yes, I agree I was expecting to find more references to inline twins and was surprised by the predominance of the term parallel. The use of the term inline is more commonly used as a reference to the relationship of the crankshaft to gearbox and drive rather than the engine itself. Longitudinal or tandem parallel twins (Sunbeam S7, Rotax 256, Kawasaki KR250 and marine engines) are far less common. Given that the policy states "consistency", if we look at the V-twin page, longitudinal V-twins occupy a subordinate position reflecting that relative rarity. Actually, there are probably enough sources to split both 'horizontal' and 'longitudinal' parallel twins and 'horizontal' and 'longitudinal' V-twins into separate topics, if someone could be bothered to write them
I cannot because I have had too much of time wasted by the stupidity and ignorance of having to question a choice as poor as "Straight-two engine", and all the bitch slapping and conniving that has ensued since. Something these people don't seem to realise detracts from the job at hand.


I have had run ins with some of these other bods before and can see the psychology and the games that are being play. I find it tiresome and counterproductive to engendering voluntary cooperation in this project, and beyond what I consider to be reasonable. The system appears to defend ignorance and reward irrationality if expressed in the terms of various policies, and benefit those with a willingness and knowledge of who and where to rat on others.
I have no idea why Dennis has fixated on me and was working up such a case, because he is obviously otherwise well informed and intelligent. Yes, I challenged his knowledge or prejudices in other areas but I don't see that as a good enough reason to be "punished" by him, or have him build up "bad marks" against me, often very falsely. He came out with strong statements elsewhere that led me to question his judgement.
Of course, people do use the internet to behave in a manner towards other people that they would never do or get away with in real life. Perhaps it is just an unconscious sibling rivalry? --Bridge Boy (talk) 12:52, 30 June 2012 (UTC)
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