Talk:Single-cylinder engine

I was thinking of adding a mention of the fastest production vehicle with one cylinder. The fastest I know of is the Piaggio X9 at 98mph; does anyone know of a faster one? --Kufat 02:09, 10 April 2006 (UTC)


 * Today probably Super Single street-race (modified motocross machine) see: http://450moto.com/ —Preceding unsigned comment added by 212.187.71.66 (talk) 00:54, 27 June 2008 (UTC)
 * Wonder what this would do with an ATK Intimidator 700, KTM 550 mxc, CR/KX 500AF, Maico 490 or similar Ring Ding Ding motor block fitted...

English?
Who wrote this page? Some of the "words" aren't even words! o_O

other engines?
It should be mentioned that single cylinder engines are also used for model aeroplanes and cars, lawnmowers, chainsaws, brushcutters etc. Why so focused on motorcycles?

Also, most steam engines were single cylinder. Is the page about IC engines only? doesn't say so in the heading...

Delete section "Fuel efficiency"
This section requires not merely a rewrite, but deletion as total nonsense.

Single cylinder engines have no inherent benefit for fuel efficiency. As engines, the number of cylinders has less influence on their efficiency than their other design attributes (i.e. efficient gasflow and combustion) and also their individual cylinder capacity (there are scaling laws that favour increasing size). Where there is any effect due to the count of cylinders, this favours multi-cylinder engines, not single-cylinder. Some "overhead" losses due to friction and windage can be reduced, if shared across multiple cylinders.

Efficiency of engines is measured as their specific fuel consumption (i.e. power output per fuel burned), efficiency of vehicles is measured as distance per fuel and takes no proportionate account of the work done to achieve this. Where a contest is restricted to "human carrying vehicles", then an obvious advantage goes to the smallest and lightest vehicle that is just capable of achieving this. Such a vehicle may be powered by a small, and likely single cylinder, engine. As described and referenced here, such vehicles have set records, have been referenced and have used single cylinder engines. However these were efficient vehicles, not efficient engines, as claimed. The engines were small above all else, and it is the low demands placed upon them that makes their consumption light, not the virtues of their cylinder count.

This whole section is a prime example of the inappropriate use of data, rather than information.

The most efficient engines have been large, complex and multi-cylindered: the Napier Nomad and Napier Deltic are particularly notable examples, the current record holders though are some large ship diesels.

I believe that this section should be deleted. At most it could be replaced by a note that many ultra-light bubble cars (and indeed motorcycles) used single cylinder engines as the simplest, cheapest and most efficient means of providing the limited power needed. However this should not be extended into a claim of engine efficiency.

If there are no good arguments for keeping this section, I intend to delete it. Andy Dingley (talk) 02:33, 18 January 2011 (UTC)


 * Yes. It was just rambling by somebody who thinks a moped is more "efficient" than a bus because the moped has a higher mpg number. --Dbratland (talk) 03:09, 18 January 2011 (UTC)


 * I went ahead and removed it, on the grounds that it was original research. The editor was advancing novel arguments, putting together their own evidence, their own examples, and reaching their own (highly dubious) conclusion. A neutral, verifiable discussion of the relative efficiency of different numbers of cylinders might be appropriate, either here, or on Reciprocating engine or Internal combustion engine. But we must stick with sources, not our own opinions nor our own elaborate theories. --Dbratland (talk) 17:11, 18 January 2011 (UTC).

Dear Wikipedia-Team,

I am a real great fan of wikipedia and the idea to share the truth and the good information for free with all the people of the world, to create a better world for us all. After the completion of my mechanical engineering degree, I dedicated 5 years of my life into the research of the evolution of the internal combustion engine and the history of the automobile. In the course of these thorough research, I read more than 300 books to this topic, to find the essential characteristics of a really fuel-efficient internal-combustion-engine. Originally I wanted to write a book about my findings. But my intention is to reach as much people as possible and help them to choose a preferably fuel-efficient motor-vehicle which meet all their requirements. I don’t want to get rich with this, I want to participate in the creation of the better world which we all dream of. So I decided to present all my findings freely to wikipedia and created the section “Fuel efficiency”. These are no theories of a weird psycho-freak. I have a german mechanical-engineering degree and have proved all my findings with trustworthy sources.

But now I must see that all of my thorough researched findings, which I have presented freely to wikipedia and which should only help to create a better world for us all, are deleted hastily without to recognize the simple truth which it contains. That makes me very sad. I thought wikipedia’s sense is to share the truth and the good information with all the people in the world, to create the world which we all dream of. These are really very thorough researched information.

Maybe you think about this deletion again and give the truth a chance. I still believe in wikipedia. Please decide for the good information and for a better world.

Kerl23BRB, 22:20, 18 January 2011 (UTC)


 * There are two problems with this section; one technical, one Wikipedia.
 * Firstly the Wikipedia issue. There is a policy called WP:No Original Research. Wikipedia is not intended as a first publishing location for any research. Get it published elsewhere in some reputable peer-reviewed context (an MSc thesis would be adequate, or a book by a reputable publisher, or a paper in an appropriate journal), then it can be re-added here with appropriate referenc
 * Secondly the technical issue. It's just wrong to claim that single cylinder engines are more efficient, of their cylinder count alone.


 * Hitlist


 * Over-simplified scaling laws (this is your main mistake). Yes, big cylinders have better surface/volume ratios so as to reduce heat loss. However they also have poor combustion behaviour, owing to the longer flame paths. This is particularly a problem for spark ignition (i.e. petrol) engines, less of a problem for direct-injection compression-ignition (i.e. diesel) engines. You might note that there are some very large diesel engines, there are no equally large petrol engines.
 * "lower revolutions mean that the piston rubbs less times against the cylinder,"
 * Fewer "times" perhaps, but we aren't counting the number of times, we're looking at distance and velocity. One of the big design limits on an engine is the maximum piston velocity. Too long a stroke (with this velocity constraint) limits the rpm redline, which limits power/capacity.


 * "single-cylinder-engine has only once the bearings "
 * An average of two crank bearings per cylinder. This is nearly twice as many as a multi-cylinder engine, with 7 bearings for 6 cylinders. More than three times as many as a V12 with shared journals and still 7 bearings. Then again, the simple count of bearings is an irrelevance, as it's more about the bearing area, which is limited by power more than cylinder number. Big engines need big bearings, and it matters little whether it's in one journal or a dozen.


 * Then you fall into the fallacy of equating light vehicles with efficient engines (see previous post).
 * Writing and even proof reading is poor. "this Volkswagen 1-Liter-Prototype has a 300cc-single-cylinder-engine" ?
 * There are no supporting references. You confuse data with information, and you weigh referencing by its volume, not by quality.
 * The rest is too poor to even waste time typing about it.


 * I don't know what books you did read, but at least one of them should have been Ricardo. Andy Dingley (talk) 23:00, 18 January 2011 (UTC)

Dear Andy Dingley,

i see your point. Now i recognize the thing which hinders you to agree with me. It's only one thing. In germany we measure the fuel consumption of automobiles in Liters per 100km, so here is fuel consumption the same like fuel efficiency. But in america you measure fuel consumption in Miles per Gallon which is the inverse of fuel efficiency. (source: http://en.wikipedia.org/wiki/Fuel_consumption_in_automobiles#Inverse_or_reciprocal_scale )

So what i mean when i speak of fuel efficiency is at the same time fuel consumption. And thats the only thing which divides us. If you see it that way, all my findings are true.

In the whole history of the reciprocating engine no multicylinder-engine/vehicle ever had a lesser fuel consumption than a comparable single-cylinder-engine/vehicle. That's the truth.

Or to say it in another way, in the whole history of the reciprocating engine, single-cylinder-engines/vehicles had the lowest fuel consumption of all competitors. That's what i want to tell the people. And when you know that, you can choose the vehicle with the fewest cylinders which satisfies all your needs, and you help to create a better world with that.

For example, in the western world, there is no mass-production-car with a pure internal combustion engine (without hybrid components or the like) which has a lower fuel consumption as the new Fiat TwinAir, whose 85hp-875cc-twin-cylinder-engine has a fuel consumption of only 4.0L per 100km. And this is at the same time the mass-production-car in the western world with the fewest cylinders. This fuel consumption is the same as hybrids like the Honda Jazz Hybrid, but the fiat costs far less than the Jazz Hybrid and can seat 4 adults comfortably. (sources: http://www.carmagazine.co.uk/Drives/Search-Results/First-drives/Fiat-500-Twinair-2011-CAR-review/  +    http://www.autocar.co.uk/CarReviews/FirstDrives/Fiat-500-0.9-Twin-Air/251295/    +   http://www.fiat.co.uk/500twinair/ )

Please give the truth a chance and put the section "Fuel efficience" back in this article. Many many people could be convinced through that, to buy more environmentally friendly cars, if the words are there for them, to read and understand.

I wish you a very long and lucky life

Kerl23brb, 11:22, 20.01.2010

PS: You are right. I have read some books of Harry Ricardo, who was the greatest enemy of friction in the internal combustion engine. But one of my favourites is the book "Schnelle Motoren" by Helmut Hütten!! (source: http://www.amazon.de/Schnelle-Motoren-seziert-frisiert-Helmut/dp/3879439745/ref=sr_1_cc_1?ie=UTF8&qid=1295519330&sr=1-1-catcorr ) —Preceding unsigned comment added by 195.37.0.7 (talk) 10:31, 20 January 2011 (UTC)


 * You are comparing the efficiency of vehicles with the efficiency of engines. These are different. This article is about engines, so should limit itself to the efficiency of engines, not confuse itself with vehicles.
 * You are right when you say that efficient vehicles use single cylinder engines. This is because efficient vehicles are small, light vehicles so that they require less power. With less power needed, that can be supplied by a single cylinder engine. It would be totally wrong to design a car that needed a "100kW engine", then to assume that the most efficient design for that engine would then be a single cylinder engine. Andy Dingley (talk) 11:27, 20 January 2011 (UTC)

Dear Andy Langley,

i see your point. When i wrote "in the whole history of the reciprocating engine, single-cylinder-engines/vehicles had the lowest fuel consumption of all competitors", i wanted to say that "in the whole history of the reciprocating engine single-cylinder-engines had the lowest fuel consumption of all competitors" and at the same time i wanted to say that "in the whole history of the automobile, single-cylinder-vehicles had the lowest fuel consumption of all competitors." And that is the simple truth. You are totally right that engines are no cars, but all wiki-articles about a special engine-configuration, like straight-Two or straight-Three, include information about motor-vehicles with this type of engine. So it should be allowed at the single-cylinder-article, too. Furthermore the consumption of historic and modern cars is a very good way to proof that single-cylinder-engines and single-cylinder-cars have the best fuel-efficience and the lowest fuel consumption of all the competition. Before World War I The single-cylinder-cars of Benz, De Dion-Bouton, Oldsmobile, Cadillac and Brush had the lowest fuel-consumption of all mass-produced cars of the world. Thats the truth. And all these cars were available with 4-5 seats. So they were real practical cars.

Between World War I and World War II the lowest fuel-consumption of all mass-production cars hat the Hanomag 2/10 PS whose single-cylinder-engine consumed only 4.0 L/100 km. Why it had the lowest fuel-consumption of all mass-produced cars? It was the only mass-produced car of that time with a single-cylinder-engine.(source: "80 Jahre Hanomag Kommißbrot : Deutschlands erster Volks-Wagen" (Horst-Dieter Görg, 2005, ISBN: 3-933802-13-X) )

Shortly after World War II the lowest-consumption of all mass-production cars had the BMW Isetta. When its production started in 1955 it became the worlds first mass-production 3-liter-car, because his single-cylinder-engine needed only 3.3 L/100 km. (source: "Isetta: Ein Auto bewegt die Welt"(Authors = Andy Schwietzer & Manfred Seehusen) )

Today the most fuel-efficient cars are auto-rickshaws, which have nearly all single-cylinder-engines. For example is the typical mileage for an indian made auto-rickshaw around 2.9 L/100 km. And an typical auto-rickshaw can seat 6-7 peoples! And these are often old-technology engines without OHC or fuel-injection. With new technology they could be much more fuel-efficient and powerful. (source: http://en.wikipedia.org/wiki/Auto_rickshaw#India )

And single-cylinder-engines really can be powerful. Look at the KTM 690 Duke R whose 690cc-single-cylinder-engine achieves 70hp and 70Nm of torque. Thats enough for all cars which weigh under 1 ton. With a turbocharger you can easily double that and you have a 140hp-140Nm-single-cylinder-engine (the Mitsubishi Evo FQ400 has also 200hp/liter). Thats even enough for a middle-class family-car like a Toyota Camry. (source: http://www.motorcyclenews.com/MCN/bikereviews/searchresults/Bike-Reviews/KTM/KTM-690-Duke-R-2010-model/  +   http://www.ktm.com/690-Duke-R.102322.19.html )

In 1996 the dutchman Jan Honee built a dragbike with a Jawa-500cc-single-cylinder-speedway-engine as base. He added a supercharger and Nitromethan-fuel and this tiny little single reached 250hp!!! And thats 15 years away. And a supercharger is far away from the potential of a turbocharger. Today such an engine could easily reach 500hp. (source: http://www.thefang.co.uk/singles.htm )

You see, single-cylinder-engines have the lowest fuel-consumption of all mass-produced cars in the world (all the vehicles which use them proof that). And at the same time they have an unexpected power-potential.

All what i say is the truth. Dear Andy Langley, could you please put back the "Fuel efficiency" section. — Preceding unsigned comment added by 195.37.0.7 (talk • contribs) 08:14, 20 January 2011


 * This is a huge waste of time. All this talk of the "truth" and the desire to enlighten the misguided people of the world shows that you have not understood Wikipedia. I recommend spending a few months trying to understand Wikipedia better by making small edits to articles that have nothing to do with engines. Pick any topic, or a hundred topics. But learn to use and be guided by sources, rather than to push your own opinions and theories. Start by reading How to edit a page, Five pillars, About and What Wikipedia is not, and follow the links to the other guidelines on how Wikipedia functions. It would also be much easier for you to work in your native language because it's clear you're not fully understanding what's being said to you, and your comments make it obvious that you're not entirely able to communicate your point. By starting small, and making it easy for yourself, you can start to understand what Wikipedia is and how to make improvements to articles. Then, maybe, you could make useful contributions on the subject of fuel efficiency.Talk pages are only for the purpose of making article better, and dragging this discussion on is not going to make the article better. --Dbratland (talk) 16:21, 20 January 2011 (UTC)

Dear Andy Langley,

its very sad that people like you dont recognize the truth when they see it. You dont understand it, so it must be false and you delete it. So the people of the world must waiting again for the truth which i wanted to give you freely. But anyway, even if you dont like to here it, this IS the truth and it will win, because the truth is that "what is" and the untruth is that "what not is". No matter how much time it will need, but finally the people will recognize that "what is". So in the long-run the truth always wins.

I wish you a very long and lucky life and enlightenment

Kerl23BRB —Preceding unsigned comment added by 195.37.0.7 (talk) 16:52, 20 January 2011 (UTC)

Lead images
I deleted an animated gif of a four-stroke engine (which is already used on that article) and replaced it with a clear image showing a single cylinder engine. The animated GIF shows a four-stroke DOHC engine, a configuration that is uncommon on single cylinder engines and is therefore unrepresentative of the type - and that is the reason that Andy Dingley removed it from the article in August 2010. However, if anyone feels strongly that this animated GIF really does belong as lead image, then let's discuss. --Biker Biker (talk) 08:28, 31 October 2011 (UTC)
 * Agree. It isn't a good illustration of what makes a single a single. --Dennis Bratland (talk) 02:38, 3 November 2011 (UTC)
 * Agreed. This isn't a single cylinder engine, therefore it doesn't belong here.
 * The issues of whether we even need to explain the cycle here, or whether it's the best image to illustrate the engines, are secondary to this. We just can't illustrate one topic by using an image of something different. Andy Dingley (talk) 10:14, 3 November 2011 (UTC)


 * I have left a warning about 3RR on Ericg33's talk page and invited him to participate here rather than continually revert other people. --Biker Biker (talk) 10:30, 3 November 2011 (UTC)

2-stroke vs. 4-stroke
There is no mention of the differences between 2-stroke and 4-stroke single cylinder IC engines. I know there is a major difference in that the firing frequency of a 2-stroke single cylinder is the same as a 4-stroke twin cylinder thus affecting the size of the flywheel. I can't think of what other distinctions might be discussed but I'm sure there are others.

--Mechestudent (talk) 16:27, 10 January 2013 (UTC)


 * Might I direct you to the article Two-stroke engine? The differences are sure to be discussed there. Sincerely, SamBlob (talk) 18:12, 10 January 2013 (UTC)