Talk:Four-stroke engine

Vandalism

This article was vandalized over several edits on 11 October 2007. My first attempt at undoing the vandalism left some junk still in the article and it took me a few tries to recover all the deleted content, sorry about the flood of edits. The result, or at least the intent, was for the current (163698357) revision to be identical to the one six revisions back (163691542). What I really needed was to view the differences to an old revision as part of the preview, but oh well. -- TSylvester 00:52, 11 October 2007 (UTC)

Concerns about the animation

The animation appears backwards, is much too fast, does not label the air and fuel intakes, and it is not even clear when the fuel is ignited, nor where the exhaust goes.68.5.64.178 07:42, 4 November 2006 (UTC)

Serious concerns about terminology

I have looked through the engine section on Wikipedia and I have some serious concerns about the terminology, which I feel is misleading or inaccurate. I should mention that I have no problems with the content of the articles. I have a degree in mechanical engineering and a strong background with engines, which alone should not give me unquestioned authority here. But rather, I'm hoping that my opinion and research will at least be considered and discussed. I have outlined below my list of problems with the terminology here:

• A four-stroke engine is NOT the same as an Otto cycle engine. There are four-stroke cycles that are NOT Otto cycles, mainly the Diesel cycle. This is, in my opinion, the most serious error.
• I submit that an Otto cycle engine does not necessarily need to be four-stroke. The generally accepted definition of the Otto cycle (which is an idealized cycle) is based on the thermodynamic cycle - isentropic compression, constant-volume heating, isentropic expansion, constant-volume heat rejection. This cycle is concerned only with the compression and power strokes. Whether or not there are intake and exhaust strokes is irrelevant. (Of course, adding boost or backpressure changes the cycle but these are not ideal for a naturally aspirated engine.) The very first paragraph in Internal Combustion Engine Fundamentals by Dr. John B. Heywood (which is considered to be one of the premier authorities on engines) reads, "The internal combustion engines which are the subject of this book are spark-ignition engines (sometimes called Otto engines, or gasoline or petrol engines, though other fuels can be used) and compression-ignition or diesel engines." This quote is being posted under fair use policy. Dr. Heywood (and I) equate the Otto cycle to an ignition by spark, and NOT to a particular number of strokes. Additionally, he equates the Diesel cycle to compression ignition. Throughout the rest of his book, he uses the terms "spark-ignition" and "compression-ignition" almost exclusively to differentiate between engine types. It is my opinion that this terminology is the most accurate and most descriptive way to categorize engines, and I suggest that it be used throughout all Wikipedia engine articles.

Any responses to my request?

Why the hell is the Otto Cycle redirected to a four-stroke engine section? The Otto cyle is an ideal cyle for a petrol engine. The Diesel cycle is also four-stroke, but it is different to the Otto Cycle. 61.69.176.55 (talk) 00:35, 30 December 2008 (UTC)

I also think that the ideal Otto cyle should be explained separately. As a Physics teacher I am more interested in the ideal model than in the real four-stroke engine. I think that the material contained in the MIT Open course should be an adequate starting point.--Gonfer (talk) 17:31, 15 May 2009 (UTC)

Signed User:Fyre4ce

i believe one stroke is one up or down movement of the piston .if something is wrong change or mark it,everyone does and even delete stuff they have no clue about .usually it will come close in the end. also language is not always exact.keep is simple most people just want essential information in a first reference and no course in thermo. good luck.Wdl1961 (talk) 01:47, 30 December 2008 (UTC)Wdl1961 (talk) 02:06, 30 December 2008 (UTC)

It is nice to have an automotive engineer here. I, for one, do not have the depth of knowledge about engines that I do about some other articles to which I have contributed. If I am at fault about four stroke and Otto, compression ignition seems a refinement rather than a departure from the principle that shocked apart Otto's early engine. Wikipedia needs to be consistent with modern technical terms, without loosing the readers in them. To the extent that it does not interfere with looking deeper into the technical literature, it seems that how real engines work is more appropriate here than idealized thermodynamic definitions. This is pointed out by the apparent failure of Carnot to lead the way to compression. (Being a physicist who has worked with engineers, I can imagine his frustration.) David R. Ingham 07:07, 17 January 2006 (UTC)

hi Fyre4ce, You are right , I am also a mechanical engineer and my search to otto engine brought me here. I place a PV and TS diagram of OTTO Cycle but some one remove it . I think these people does not understand the diffrence between otto cycle and four stroke cycle.I strongly belive that there should be two pages one for four stroke engines and one for otto cycle. NOT ALL ENGINES RUNNING ON FOUR STROKE CYCLE RUN ON OTTO CYCLE.

User:124.125.21.126 , 28 July 2006

David,

Thanks for the reply. I'm very new to Wikipedia and, if nothing else, it's nice to know that someone out there is listening. :-) I think it's entirely possible to use a standard in terminology that will be both informative and not stand in the way of more in-depth research. I also think it's important to make reference to the idealized thermodynamic cycles, because I think understanding how a real engine relates to its idealized cycle is an important part of understanding how the engine works (and this was how it was taught at the university where I studied - ideal model first, how the real world situation differs next). What do you think should be my next step? Before I would consider making sweeping changes to the naming and organization of the information in the engine section, I would want to go through all the main articles carefully and lay out a new standardized and corrected scheme. This will take some time. I would like to get approval from other editors but I also don't want to find myself patiently waiting for months for a "sure, that sounds good" that may or may not ever come, and that may or may not be from someone with a background in the subject. Since you seem to have experience writing on Wikipedia on technical topics, I am hoping you can give me some advice.

Thanks, Fyre4ce 23:12 Jan 17, 2006 EST

• You're not likely to find any definitive editor of this article to approve your endeavor. Even if one or two people tell you it's okay, that's not how it should work. The process is a bit different. Just make the changes, and as frustrating as it may be, others will come along and change whatever they think is not right. Like they say, be brave about editing... --flyhighplato 05:07, 18 January 2006 (UTC)

"....Scalpel!" (It will actually take me a while before I'm really ready to start cutting and pasting.) Fyre4ce

The term 'four-stroke' is widely used as a synonym to the Otto cycle, but I agree with you when you say this is incorrect terminology. I urge you to start editing. This article as well as the Diesel-related articles all require some major reconstruction, as much of the terminology is incorrect and the loose connections between an idealized cycle and a real world engine application needs to be set straight. - Victor van Poppelen (talk • contribs)

The Otto cycle and four-stroke cycle are different things. I came to this article hoping to explain to a friend the difference between the diesel and otto cycles, and instead found a rough description of the four-stroke cycle that conflates the diesel and otto cycles as if they are the same thing. I agree with a move to reconstruct - this article would make a good base for the definition of four-stroke and the otto cycle could be described properly.

I would have to think there should be a differentiation between 4 stroke and 4 cycle. There are six distinct cycles in a four stroke gasoline spark ignition engine: 1. Intake, 2. Compression 3. Combustion 4. Blowdown 5. Exhaust 6. Overlap

The 'blowdown' period when the piston is on the power stroke and the exhaust valve opens until it reaches BDC. Once the exhaust valve is open, power is no longer being produced in the cylinder and the expanding hot exhaust gasses are already moving out the exhaust system. This is key to efficiently evacuating exhaust gases, as using the piston to push out the full volume of exhaust gas from the cylinder would result in severe losses to power.

The overlap period is also a key cycle in the four stroke gasoline spark igniton engine. It is the period near TDC exhaust when both the intake and exhaust valve are open at the same time. During this cycle the exhaust gases are exiting the cylinder, and as the intake valve opens the velocity of the exhaust gases exiting the cylinder cause fresh air to purge the cylinder of any remaining burning gases for a brief instant before the exhaust valve closes. —Preceding unsigned comment added by 216.139.21.100 (talk) 06:14, 28 March 2008 (UTC)

You forgot the Moistening Cycle and the Dry-out Cycle, so there are really eight cycles. —Preceding unsigned comment added by 71.234.211.101 (talk) 22:01, 5 April 2009 (UTC)

It appears that the incorrect use of terminology has caused the foundational problem here. The basic issue is with the use of the word "stroke" when one means "cycle". The stroke is the distance the piston travels in one direction or the other. The term cycle has to do with the total process of number of full transits of the piston, up or down. Therefore the actual name is four-cycle ICE, as opposed to two- or six-cycle engines. - KitchM (talk) 22:34, 28 May 2011 (UTC)

The use of the terms "two cycle", "four cycle", or "n-cycle" are wrong. "Stroke" and "cycle" not synonymous and calling something "four cycle" is akin to referring to a computer "cracker" or telephone "phreaker" as a "hacker". It is a suborning of the terminology and should be discouraged even if it is commonly understood vernacular. 71.96.8.17 (talk) 04:13, 14 October 2013 (UTC)

mnemonic paragraph

I'm removing the following paragraph since it looks unencyclopedic to me. I can't see any way to fix it and, honestly, no reason for such a mnemonic in an encyclopedia (it's not a high school clue sheet) --- cbraga 20:40, Jun 9, 2004 (UTC)

One way to remember the four strokes and their functions is the series "suck, squeeze, pop, phooey", or alternatively "suck, squeeze, bang, blow". The four "strokes" are also present at each stage of a jet engine, where they are performed simultaneously rather than as a sequence.

And yet it is notable as a mnemonic (used for instance to answer a four year-old's question, "how do cars work"). But if it has no place in wiki, so be it. Agingjb (talk) 12:44, 17 September 2015 (UTC)

Desmodromic valve timing

I'm thinking of doing the same to the Desmodromic valve timing section. Does anyone have and idea about how to fix it?

Acegikmo1 01:13, 11 Jul 2004 (UTC)

I've rewritten it - see what you think. Incidentally I thought that the mnemonic above was actually quite worth keeping - it's a common phrase and including it to my mind doesn't subtract from the "encyclopedicness" of the article, whatever that means. Graham 03:28, 11 Jul 2004 (UTC)

If you'd like to reinstate it, I wouldn't object.

Acegikmo1 03:35, 11 Jul 2004 (UTC)

Hello, I'm french, and read this article. I'm sorry to say that i disagree with the interest of the desmodromic valve train. The only advantage of this device is to avoid the problem of inertia at high speeds. The advantages you explain is the one of VVT (variable valve timing) or VTEC from Honda. (I'm motorist, see the Page of Rémy in the french wikipedia)

• Hello. Are there factual inaccuracies in the desmodromic section? The article currently states that the advantage of desmodromic valves is that they perform better at high speeds, which you seem to agree with. I don't know anything about it, though, so if you see inaccuracies, please feel free to fix them or point them out. -- Wapcaplet 15:48, 24 Oct 2004 (UTC)

For reference : http://scarbsf1.com/valves.html Ericd 21:50, 16 May 2005 (UTC)

Desmodromic valves have the advantage that the force varies according to the speed (the valve acceleration) instead of depending only on the lift and the spring stiffness. At least in principle, this means low wear and friction at low speed combined with no valve float at high speed. It may only save reciprocating mass if materials like carbon fiber, that can't make good springs are used. Otherwise, like with Panhard's torsion bar valve springs, the lever will weight as much as the spring would have. Another option is sleeve valves (as Panhard used earlier) that rotate instead of reciprocating, but coil valve springs work better than anyone would have expected. David R. Ingham 17:02, 6 January 2006 (UTC) For reference : link title End problem off valves

For this article animations [1] Andrew Feliks 30 March 2009 —Preceding unsigned comment added by 77.114.30.205 (talk) 14:25, 30 March 2009 (UTC)

Animation

The 4-stroke animations are broken. They don't run in Windows Media Player 9 or Winamp, as far as I can determine. They should be fixed or removed. Quicksilver 19:15, 15 Jun 2005 (UTC)

Has this animation been nominated as a featured animation or picture or whatever? It is very nice. David R. Ingham 06:02, 6 January 2006 (UTC)

Animation Direction

Cool animation!! I would like to point out that 99.99% of all IC engines rotate clockwise when looking at them from the front. The "funny" rotation immediatly seemed un-natural to me. However, this view could be looking at the engine from the flywheel end, or the 2nd engine in a contra rotating marine application.

The monikers: suck, squeeze, bang, blow were taught in the U.S. military. 69.213.205.190 18:03, 5 October 2005 (UTC)

That number seems too large. In two piston-engine airplanes, unless costs of stocking pars are cut, one goes clockwise and the other counterclockwise. In one engine airplanes, German-Swiss and Anglo-American engines turn, or turned, in opposite directions, as seen in photos showing the propellers. Reed valve two strokes can run either way. The Messerschmitt KR200 and Spatz Kabinenroller used this instead of a reverse gear. Small model airplane engines can be used as pushers or with left or right propellers, by starting them in the opposite direction.

Anyway, I don't see anything showing wether the annimation is from the front or the back (or the engine is transverse mounted). David R. Ingham 05:56, 6 January 2006 (UTC)

This looks correct as viewed from the flywheel (rear) end, assuming a left hand drive USA vehicle, with: 1. an inline engine, transversely mounted with the transaxle toward the driver's side. 2. the driver's side bank of a V engine mounted classically. 3. the forward bank of a V engine mounted transversley with the transaxle on the driver's side. The spark plug is centered in the combustion chamber, and there appear to be separate intake and exhaust camshafts, so I would assume this matches #1 above. (very common DOHC arrangement) BobJones 23:48, 20 June 2006 (UTC)

Output Limit paragraph

The last paragraph in this article specifically states that it applies to four-strokes. Piston speed, however, is the limiting factor on all reciprocating engines, not only four-strokes. Shouldn't someone move this section to reciprocating engine page? - victorvp (talk)

History

According to

• Hardenberg, Horst O., The Middle Ages of the Internal combustion Engine, Society of Automotive Engineers (SAE), 1999

the 1862 Otto (O#O) engine did not have exactly the modern four stroke cycle and did not work for long.

Also it says he knew nothing about Carnot and discovered the advantages of compression by turning the flywheel backward by hand! David R. Ingham 06:13, 6 January 2006 (UTC)

The statement that he invented the four stroke cycle was not exactly what the German courts found. His patent was not held to cover internal compression or even the four stroke cycle. See internal combustion engine#history. David R. Ingham 06:02, 10 January 2006 (UTC)

terminology and focus problems

I agree with Fyre4ce about the problems with this article. The "four-stroke cycle" describes a particular operating concept for an internal combustion reciprocating piston engine; it is not a synonym for the Otto cycle (despite the fact that Otto's first engine was indeed a four-stroke).

The Otto cycle is an idealized thermodynamic model of the processes taking place in a gasoline, spark-ignited engine; the title "four-stroke cycle" should be restricted to a page describing the details of operation of a real four-stroke piston engine (e.g. valve timing, output limits, volumetric efficiency, etc.), and a page describing the Otto cycle should be far more focused on the ideal thermodynamic cycle (isentropic compression/expansion, constant volume heat addition, constant volume heat rejection, and the analyses that fall out of that simple model). See the page on Carnot Cycle to get an idea of what I'm talking about. It's fine to enumerate the differences between reality and theory, but in writing about a theoretical construct, the focus ought to be on the details of that construct.

I'd be happy to help rewrite an article, but I don't know anything (yet) about the shorthand used in producing things like integrals and section headings. IOW, I'm not ready yet. I will need to study the "how to edit a page" guide first.

Joe Frickin Friday 18:14, 27 January 2006 (UTC)

Four-stroke engines utilze Carnot cycle? Moreover, somebody subtitled an Otto cycle graph as Carnot cycle. 89.75.129.67 (talk) 17:57, 26 September 2011 (UTC)

"Output limit" paragraph

There is a lot of confusion here, and this does not seem the best place to discuss these things. Rod/stroke ratio seems independent of which cycle is used. Without supercharging, the output limit depends most on the air intake. I suggest starting over. David R. Ingham 07:04, 7 March 2006 (UTC)

I agree with that. There are other limiting factors which predominate depending on context. Piston speed limitations are real enough but it never stopped shortening the stroke and spinning it like a turbine anyway. Overall air flow is a more important limiting factor. The rod/stroke ratio thing is a somewhat overblown pet theory of Smokey Yunik but it shouldn’t be presented as the ultimate power secret. The section should be tweaked.--=Motorhead 00:52, 10 March 2006 (UTC)

Couldn't agree more with both the above postings - air flow/breathing capability is the most important factor. Practical mechanical limitations are of course still relevant. I also think the undersquare versus oversquare implications should be clarified (oversquare lends itself better to high RPM because of piston speed and acceleration, and because greater area for valves allows breathing to be maintained at high speeds; there is a popular misconception that undersquare engines produce more torque for the same swept volume due to longer moment arm of the crank throw - forgetting that the smaller piston has less total force acting on it from the combustion gases, I believe the advantage of undersquare engines is that less exposed surface area of the combustion chamber means less heat energy is lost so more can be converted into useful work). I vote for starting over - a total rewrite rather than trying to patch-up the existing section on Output limit. —Preceding unsigned comment added by Mimiselfani (talk • contribs) 01:34, 7 June 2008 (UTC)

see edit Rod/Stroke ratio Wdl1961 (talk) 23:40, 4 January 2009 (UTC)

motor fetishism

The reverted edit [[2]] reminds me of Coleman's abnormal psychology textbook (I think that may be Coleman, James C. (1964). Abnormal Psychology and Modern Life (3rd ed.). Illinois: Scott, Foresman and Company. Or the first edition, 1950.) His example was a boy who was sexually aroused only by exaust pipes. This edit is similar. David R. Ingham 04:41, 8 March 2006 (UTC)

Efficiency

Some typical and maximum efficiency levels would be useful. Tobyw 12:29, 8 March 2006 (UTC)

valve clearance adjustment

Some formatting needs to be fixed in this section, there's a random "Headline Text" thing and some writing that goes on forever off to the right (at least in Safari) Thetrump 23:06, 6 April 2006 (UTC)

I don't feel like this section belongs here at all. Maybe there could be a separate article on maintenance procedures for 4-stroke engines. If it is decided that this article should include maintenance procedures, they should go in their own section, and would presumably contain more than just a single procedure. Furthermore, the valve clearance adjustments outlined here are specific to engines with solid valve lifters, which very few, if any, modern massed-produced 4-stroke engines utilize.

Removed illustrations

I'm certainly biased (since I made them) but I'm somewhat dismayed to see the individual illustrations of each stage in the cycle replaced by a single animated .gif (this edit). While the new animation is very nice (and more realistic-looking than my pics), I don't think it's an adequate substitute. This is especially true for those (like me) who find continuously animated graphics annoying, and have their browsers configured to play them once only. Why not include both still and animated versions? It's not like this article suffers from an overabundance of images :-) -- Wapcaplet 13:39, 28 July 2006 (UTC)

Compression stroke and Exhaust stroke

I have a request: Someone knowledgeable about engines please write the above two articles. The animated image Image:4-Stroke-Engine.gif is scheduled to be Wikipedia:Picture of the day on November 4, 2006 and will appear on the Main Page. However, it is against policy to have red links on the Main Page, so you have until then to get these articles written, or at least stubbed. Thanks. howcheng {chat} 17:01, 4 October 2006 (UTC)

shifted from article

shifted this content added by an anon IP

their are major differences in a two stroke and a four stroke two stroke means that the (for example) dirt bike motor receives power on every turn of the crank shaft creating shorter faster bursts of power. the four stroke receives power on every other turn of the crankshaft creating bigger longer bursts of power. The two stroke has something called a power band which is when the bike hits a certan RPM and explodes with power where a four stroke has all of its power when you need it no wait for a power band.

add it in if it seems to be useful, I couldn't figure where to put it. thanksxC | ☎ 08:02, 6 July 2007 (UTC)

Four stroke = Otto

This is big mistake, can not beleive someone can put these two things as one. It looks that diesel engine can not be four stroke.--Billy the lid (talk) 10:05, 16 May 2008 (UTC)

effect of usage 4 stroke

dun know?? anybody knows?? —Preceding unsigned comment added by 60.50.78.58 (talk) 07:48, 13 July 2008 (UTC)

car go. NJGW (talk) 17:11, 13 July 2008 (UTC)

Bad Article

Why does the animation not even follow the otto cycle? In fact, why is the Otto cycle (an oscure engineering/thermodynamic representation), a dominating feature of this article? It doesn't represent a single real engine, and is not the only thermodynamic model out there for a four stroke. And no-one except mechanical engineers would be interested, and no-one except mechanical engineers would be enraged by the inaccuracy of it all! Why not just tone down the Otto business and tone up the 4-stroke practical info, applications and what-not? 86.44.202.31 (talk) 22:52, 16 September 2008 (UTC)

Why isn't there more information on the otto cycle that redirects to this page? The four stroke cycle redirects here too. The diesel cycle and diesel engine have separate pages. Shouldn't the four stroke engine and four stroke cycle have separate pages also? It is clear these are two separate subjects addressed to those who would expect to find different information in each. 84.44... is one person to indirectly suggest this, I second it. —Preceding unsigned comment added by 64.56.17.154 (talk) 02:44, 18 October 2008 (UTC)

I'm not an expert, but I'm editing this article anyway :-)

Not only is this a bad article, but this talk page is full of almost two years worth of whining and complaining by people who aren't doing much of anything to fix the situation. What an awful Talk page this article has. Yeesh.

I am not an expert, but I am wading in anyway attempting to fix the major formatting and layout problems here, and trying to improve it with more general information and cross-article links. (You can blame me for the Otto engine video. I recorded and uploaded it.)

Wikipedia is a collaborative project built by non-experts, and so if people think it's a bad article, you can't do much worse to it by trying to fix it, can you? So please, FIX IT rather than complain about it.

(Please refer to the Wikipedia editing policy page Wikipedia:Be bold for more confidence in your editing skills.)

DMahalko (talk) 01:07, 23 October 2008 (UTC)

"Relational Vibration"--need new term?

I've added relational vibration, as it is referred to in my text book, as the effect the speed of pistons can have on the rest of the vehicle. This is referred to in my book as "Relational Vibration", but I've noticed that the copyright is from the mid 90's...does anyone know if there is a new term to refer to this? —Preceding unsigned comment added by Williamsburgland (talk • contribs) 23:48, 28 November 2008 (UTC)

This is a pure invention on your part, so cite your references. Andy Dingley (talk) 00:08, 29 November 2008 (UTC)

I think it's completly unprofessional of you to keep accusing me of simply inventing this...citation added —Preceding unsigned comment added by Williamsburgland (talk • contribs) 02:50, 29 November 2008 (UTC)

I've reverted this again, as the ref you added doesn't appear to include it:

Finally, increased piston speed can impact something known as relational vibration, or a vibration felt throughout the vehicle as said vehicles forward speed approaches the speed of the pistons. The higher the piston speed, the greater the effects of relational vibration.

• http://books.google.com/books?id=mX1-OJBQ6ngC&pg=PA378&lpg=PA378&dq=piston+speed+fuel+efficiency&source=web&ots=ijrmSC2ryX&sig=akBenKYwvHm3soTVE8bblV_UCPU#PPP1,M1

Could you please point to where (page number?) this ref supports your claim? Andy Dingley (talk) 22:07, 30 November 2008 (UTC)

Apologies on the late reply...it appears as though the PDF I cited did not include the entire document...I stand by my material but cannot provide a link, so per Wiki guidelines I agree that the term should be removed. —Preceding unsigned comment added by Williamsburgland (talk • contribs) 18:19, 12 December 2008 (UTC)

Can you please cite a page, so that I can check the book. I can't see it, nor can I see it in any of my fairly extensive library of similar books. Andy Dingley (talk) 22:09, 12 December 2008 (UTC)

there is coverage of relational vibration between engine and supporting structure on pg 292 http://books.google.com/books?id=mX1-OJBQ6ngC&pg=PA378&lpg=PA378&dq=piston+speed+fuel+efficiency&source=web&ots=ijrmSC2ryX&sig=akBenKYwvHm3soTVE8bblV_UCPU#PPP1,M1
Wdl1961 (talk) 22:17, 25 January 2009 (UTC)

I've worked in the field of automotive noise and vibration for 30 years and have never heard this term. It also does NOT appear in the textbook Wdl cites, according to google search. p292 certainly does not discuss it, or indeed anything associating piston speed and vehicle speed (an absurd concept BTW). Greglocock (talk) 12:10, 27 January 2009 (UTC)

I've worked in high-precision optics, and I'm somewhat familiar with it! The concept is real enough, but it isn't going to happen in a car engine (for engineering-viable values of piston speed and road speed). It has been a problem in the past with some steam paddleships. As to the book, then it's not in my paper copy anywhere I can find it, nor in the index, nor on my p292. Andy Dingley (talk) 13:44, 27 January 2009 (UTC)

there is coverage of relational vibration between engine and supporting structure on pg 292 http://books.google.com/books?id=mX1-OJBQ6ngC&pg=PA378&lpg=PA378&dq=piston+speed+fuel+efficiency&source=web&ots=ijrmSC2ryX&sig=akBenKYwvHm3soTVE8bblV_UCPU#PPP1,M1
just delete "relational" and read the rest of pages 291-292 -293 dealing with general vibration
Wdl1961 (talk) 16:21, 27 January 2009 (UTC)

There is coverage of Bigfoot in that ref if I delete the word "vibration" and insert the word "sasquatch"! You can't treat a reference in that way.

"Relational vibration" has a definition. By the nature of that definition, it's not going to affect cars and car engines. Vibration from the engine certainly does, but it's of other forms and not describable under that definition. The effects of coupling through the engine mounts (and expecially notions of "tuning" resonant frequencies around such mounts) will have vastly more influence on vibration into a car chassis than the road speed at which it's travelling. Andy Dingley (talk) 17:32, 27 January 2009 (UTC)

try tuned , coupled ,transmitted , oscillation, noise , critical frequency,vibration,resonance,coupling,
every piece of machinery or computer i worked on/with had one or more of these and did not care about the label.
yuor computer has a relational frequency with the transmitter,eardrums?
also try classification,groups,classes,relations,concepts
Wdl1961 (talk) 21:40, 27 January 2009 (UTC)

Nobody is denying that engines vibrate and cause the surrounding structure to vibrate. We're just saying that the phrase 'relational vibration' has no particular meaning or usage in this field. I suppose this means I have to check ALL the references you've given now to see if they really support the statements made, since you don't seem to understand why this is an issue. Thanks a bunch. Greglocock (talk) 22:30, 27 January 2009 (UTC)

all of the above is simply energy transfer of some freqency /frequencies of some magnitude from point a to point b (sometimes? both ways)
each discipline thinks theirs is unique ,nothing unique about it
Wdl1961 (talk) 01:28, 28 January 2009 (UTC)

I don't know what you are trying to prove. Can you find JUST ONE SOLID reference to the phrase "relational vibration"? If not then we aren't having a discussion, you seem to be trying to justify providing a misleading reference. To help you out, I have 3 Noise and Vibration reference books by my desk, here at home, I also have 3 engine textbooks. Now, guess how many of those have the phrase in the index? None. It doesn't appear in the McGraw Hill dictionary of Physics and maths either. So it is either a very specialised term, or a neologism, or a mistranslation. I favour the latter, relative vibration would be my guess, but of course that has nothing to do with matching piston speeds and vehicle speeds, which is still an absurd concept.Greglocock (talk) 01:51, 28 January 2009 (UTC)

Q.E.D.
Wdl1961 (talk) 02:10, 28 January 2009 (UTC)

google Results 1 - 10 of about 91,600 for relational vibration. (0.06 seconds)

Sound Accord - - The Sound Self Part Two When we are fluent in the language of

relational vibration

, we inhabit the territory of the heart with confidence, grace, and ease. ... www.sound-accord.com/-_the_sound_self_part_two - 16k - Cached - Similar pages
Wdl1961 (talk) 03:06, 6 February 2009 (UTC)

I have to say you are wrong that this relational vibration term exists. You performed a bad google search. Try searching google with relational vibration in quotes. The number of results drops suddenly to about 120. Then add the word engine to clarify its relation to this topic. It drops to 30, almost all of which, surprisingly, in one way or another reference this talk page. So yes my friend, you are in fact the only person on the entire internet using relational vibration in conjunction with engines. This case seems settled. 128.6.83.117 (talk) 01:54, 7 May 2009 (UTC)

the phenomena excists. all of above about the label .so use the label and ref you like and change it.

then the problem is solved.

Wdl1961 (talk) 14:27, 6 July 2009 (UTC)

What on earth are you on about? Nobody has provided a single decent ref to the idea in relation to engines. Greglocock (talk) 10:20, 7 July 2009 (UTC)

every mechanical engineer knows what it is or he will find out the hard way

//tacoma narrows bridge\\

maybe we need a new wiki article

Wdl1961 (talk) 14:07, 7 July 2009 (UTC)

In relation to the Tacoma Narrows Bridge, you're probably referring to resonance (which it seem, ironically, wasn't actually the cause of the Tacoma Narrows Bridge collapse despite what many believe). Resonance does most certainly occur in engined, but has never been described using the term "relational frequency" anywhere ever.

To be honest, I must say "relational frequency" sounds like a term that describes the phenomenon of resonance quite well (a phenomenon caused by two the relationship between frequencies), but Wikipedia is not the place for coining new phrases. _ɹəəpıɔnı 15:47, 7 July 2009 (UTC)

I'm not sure why we need a new phrase anyway. The OP was originally suggesting it was to due to the matching of piston speed and vehicle speed, which is laughable. OT Yes, it's funny the way that everybody who sees the Tacoma film in high school is taught that it was a resonance. Greglocock (talk) 23:19, 7 July 2009 (UTC)

what is the term and refs we should use ??

i (mistakelingly) thought that was the original issue

Wdl1961 (talk) 00:03, 8 July 2009 (UTC)

there is a vibration article and Torsional vibration article in wiki

Wdl1961 (talk) 01:51, 13 August 2009 (UTC)

edit Rod/Stroke ratio

for a basic article this section is very long with mostly insignificant info .
belongs in racing article maybe
Wdl1961 (talk) 03:20, 4 January 2009 (UTC)

---

Rod/Stroke ratio

see the 28 January 2009 article revision Wdl1961 (talk) 22:03, 28 January 2009 (UTC)

Highlighted Issues on page

I replaced the cleanup box on the page with one highlighting the articles' issues more precisely. I think DMahalko is absolutely right in his comment here. There's no use complaining and then not doing anything about the article, and it's fairly ridiculous that it has gone over 2 years without improvement. Anyway, I'm not an experienced Wikipedia editor, but this is a subject I know at least a little bit about so I'll attempt tackling it when I have the time, maybe late next week. In the mean time, if anyone else has an interest in helping out, or has suggestions, do comment. _ɹəəpıɔnı 20:38, 25 February 2009 (UTC)

to shift to racing article

I suggest shifting to racing article Ierrotpre (talk) 10:21, 22 March 2009 (UTC)

CHP engines

The source [1] given in the very last paragraph for Efficiency and CHP engines is very confusing and not very informative.

A few links i found that explained it much better are

http://www.toolbase.org/Technology-Inventory/Electrical-Electronics/combined-heat-power

http://www.northeastchp.org/nac/CHP/basics.htm

I'm not confident in my editing abilities to make this change myself —Preceding unsigned comment added by 75.180.8.80 (talk) 02:45, 23 March 2009 (UTC)

Scavenging pump/blower?

The introductory section ends with "The largest and intermediate size diesel engines are usually two-cycle engines, requiring scavenging air pumps or blowers." Can someone please explain what a scavenging air pump or scavenging blower is please? This piqued my interest because I read the following on the British Rail Class 55 article: "The Class 55's engines were not turbocharged, although they did have scavenging blowers." It would be interesting to learn how a scavenging blower relates to a turbocharger. Thanks!--Rfsmit (talk) 21:17, 3 August 2009 (UTC)

Okay, a visit to the Two-stroke engine article cleared that up. The mention of "scavenging" should be removed from this article, given that it only applies to two-stroke motors.--Rfsmit (talk) 21:23, 3 August 2009 (UTC)

No, it's worthwhile noting that because a two stroke isn't a four stroke, they require this extra equipment. There's little between them in terms of thermodynamic cycle, it's just that the four stroke does 4 things in one place over time, the two stroke splits the same things into more than one place, so can use the cylinder for a power stroke in every revolution rather than every second revolution. Nor are all scavenge blowers Roots type. Some are mechanically driven centrifugal blowers, these days most are probably turbochargers. Andy Dingley (talk) 00:32, 4 August 2009 (UTC)

if turbocharger it needs power at startup. Wdl1961 (talk) 03:53, 4 August 2009 (UTC)

It doesn't need power at startup, it just doesn't spin and so the scavenging is ineffective until the engine starts to turn over under its own power and the turbo can start to spin up. Yes, this does tend to make startup exhaust a bit claggy, until it settles down. Andy Dingley (talk) 10:16, 4 August 2009 (UTC)

have not seen a big diesel without a positive displacement pump but never say never . i would try to get a ref in it and i am curious . you could put all of this in the article Wdl1961 (talk) 13:39, 4 August 2009 (UTC)

If you haven't seen one personally, then I'm sure they don't exist. Make sure you speedy delete the Deltic articles then. Andy Dingley (talk) 14:21, 4 August 2009 (UTC)

i hate to admit there are things existing i have never seen and certainly being build right now. just fix the article wih the best info, good luck.Wdl1961 (talk) 14:49, 4 August 2009 (UTC)

Why do you think the article is broken and what needs to be fixed? Andy Dingley (talk) 16:33, 4 August 2009 (UTC)

both the four and two stroke articles should come to essential points sooner and clearer.the details should come later.Wdl1961 (talk) 18:26, 4 August 2009 (UTC)

removes moisture from the engine oil by drawing crankcase

""Efficiency is also intentionally reduced to improve engine reliability and service life, such as with positive crankcase ventilation, which removes moisture from the engine oil by drawing crankcase vapors into the engine intake.""

it would be nice to get a ref with a percentage loss.

Wdl1961 (talk) 04:06, 11 August 2009 (UTC)

I agree. You asked for the ref, so you have the motivation. Get to it. ;) -- DMahalko (talk) 05:39, 11 August 2009 (UTC)

i think it is less than +/- 0.1 % Wdl1961 (talk) 12:12, 11 August 2009 (UTC)

False Reference

The reference at the beginning to Otto have any relationship to Beau De Rochas is FALSE. Otto's work was based on Etienne Lenoir's 1860 Atmospheric Engine. I am removing that reference. I am inserting the factual reference. Krontach (talk) 05:39, 22 May 2011 (UTC)

Four-stroke engines with high power-weight ratio

Can perhaps the differences between the four stroke motors be explained in particular in regards to power-weight ratio. For example, the Radial engine and Napier Deltic have very high power-weight ratio's 91.182.145.107 (talk) 14:17, 6 November 2011 (UTC)

Confusion

The Section numbered 3.1.1 and headed 'Otto Engines' confuses fractional distillation, a purely physical process that separates different molecules without altering them, and cracking, a chemical process that breaks molecules into smaller ones. This is definitely an error. The section also implies that low flash point is always directly connected to low octane number, which I suspect is also an error. 86.152.112.92 (talk) 23:52, 21 October 2012 (UTC)

You are absolutely correct; the process described, and the illustration, are of fractional distillation, using a fractionation tower. I believe it may also confuse "low weight", with "low molecular weight"; it appears to suggest that "low weight" compounds rise higher because they weigh less. In fact, low molecular weight compounds boil at lower temperatures, and travel further up the column, the temperature of which decreases along its length, before condensing and being drawn off as a characterised fraction such as kerosene. It would not matter if the tower were horizontal, as long as it has a temperature gradient, fractionation would work the same. I suppose the real issue is that a discussion of four-stoke engines should not include an explanation of anything that does not make an engine a four stroke engine; plenty of four-stroke engines run on ethanol, biogas, biodiesel and even used cooking oil. The refining of crude mineral oil is irrelevant. 58.175.42.9 (talk) 12:29, 4 April 2013 (UTC)

Lead section too big

I think the lead section of this article is too big. The part about the description of the stroke could easily be made into a separate section; so could some of the history, it's duplicated bellow anyway.

Aisteco (talk) 18:15, 9 August 2013 (UTC)

GIF

The gif at the top of the page is missing some illustrations. The spark plug fires twice in a 4 stroke engine. Once during power stroke, again during the exhaust stroke. The image only shows the spark igniting during the power stroke. Maybe a side note? 199.19.248.20 (talk) 01:23, 12 April 2016 (UTC)

Nope, a 4 stroke engine only requires a single firing of the spark plug at the start of the power stroke. However, many 4 stroke engines add an extra firing during the exhaust stroke to clean-up any unburnt fuel. This helps emissions but is not a strict requirement of the 4 stroke engine. Practically all engines with a distributor (ie typically older than 1990) use single firing.  Stepho  talk  01:46, 12 April 2016 (UTC)

Can we include your reply as a side note to the exhaust phase? 199.19.248.20 (talk) 02:16, 12 April 2016 (UTC)

Sure. Go for it. Although maybe wait a little (a day?) for others to make suggestions. Stepho  talk  03:11, 12 April 2016 (UTC)

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Wikipedia

I hope,This page is very helpful...plz supporting. Shriya chaturvedi (talk) 12:09, 1 March 2021 (UTC)

Humphrey Pumps

Is it worth including a mention the Humphrey pump? They were in most cases four stroke ICEs, although they were distinct in that they had no pistons, force for imparted directly from the gas to the water, or vice versa. In terms of thermodynamics, they were most similar to Atkinson engines, utilising a variable stroke length. — Preceding unsigned comment added by 81.104.42.30 (talk • contribs)

Certainly. That was a type of ICE I had never seen before and I found it interesting.

Don't forgot to sign your talk page comments with 4 tildes (~~~~) .  Stepho  talk  22:03, 2 May 2021 (UTC)

Reverting twice now

Stepho-wrs, did you read the source at all?

"Most modern internal combustion-powered vehicles are 4-strokes, powered by either gasoline or diesel fuel."

You are being unreasonably obtuse here. Qualified and reinserted. Dennis Brown - 2¢ 21:32, 19 November 2021 (UTC)

Damn. I found the sentence just before it but somehow missed that one. Although I think the source itself isn't clear about what it counts. Do motorised vehicles include container ships (massive 2 stroke diesels), jet planes (Brayton cycle), motorbikes (2/4 stroke), golf carts (electric), personal old-age scooters (electric)? They also don't say if they are couning only in America, only in western countries or also include India and Africa (where 2 strokes are popular). I think they are trying to say that most road vehicles (ie passenger cars, road going trucks, motorbikes) in the US are 4 stroke. But they only say it as a side comment and don't go into specifics. Not a good reference for the point it is being used to support.  Stepho  talk  22:38, 19 November 2021 (UTC)

Are you saying you believe it is incorrect and most cars/trucks/motorcycles/vehicles are 2 stroke? The definition of a vehicle "a thing used for transporting people or goods, especially on land, such as a car, truck, or cart" by itself clarifies that we are talking about land vehicles, not ships. It isn't at all common to call a ship a "vehicle". If you want to improve the source and/or wording, that's fine. Most people's interactions from day to day (all over the globe) when it comes to motorized transport (buses, taxis, cars, trucks, motorcycles, trains) are what we are talking about. The majority of interactions with these motors, by far, is going to be four stroke, this includes diesel trains [3]. This is worth mentioning in the lede, as it tells the reader that the topic of the article is what is most common in their own day to day dealings. Dennis Brown - 2¢ 13:10, 20 November 2021 (UTC)

Heh? Are you claiming that a ship cannot be a motorised vehicle? Of course a ship can be a motorised vehicle. A typical oil tanker or modern passenger liner is a ship and is motorised. The claim in both the article and the refence was to motorised vehicles - no qualification was given to limit it to land vehicles. The article made the claim about 4-stroke being the most common and then gave a list of some example applications but this sample list is separate from the claim and not supported by any reference.

Do I believe the statement? Undecided - far too little information is given. I believe it is true in the context of road going vehicles in western countries. But the reference didn't say that. If you look at the context of road going vehicles in India then 2-stroke motorbikes become a large force that needs to be quantified. Africa is an unknown figure in this equation that might swing either way. China used to have lots of 2-stroke motorbikes back in the 1990s (personal experience) but they have pretty much outlawed them now. Not sure about Russia.

The reference made an off-the-cuff, throw-away comment about them being the most common. It provide no reasoning or support about how they came to that conclusion, nor even qualification about which domain it was applicable too. Given that it is informal webpage talking to potential US students, I can only assume that the context of the reference is road-going, US vehicle. The article then takes that as a bold claim that all internal combustion vehicles (which includes vehicles in India, ships, jet planes, golf carts, etc) have 4-stroke engine as the most common variation. A bold claim from a weak source.  Stepho  talk  23:17, 20 November 2021 (UTC)

This is why I said you are being obtuse. Dennis Brown - 2¢ 01:13, 21 November 2021 (UTC)

Then you will need to educate me. By the way, under WP:BRD we should technically revert the claim.  Stepho  talk  03:19, 21 November 2021 (UTC)

Technically, two people want it included and one doesn't, so there is more to it. I noticed your addition to the source, which is perfectly fine. I'm working on other sources, but real life gets in the way. Whatever the outcome, it makes perfect sense to state and demonstrate how common the engine is, particularly since virtually every automobile on the planet uses the technology, just for starters. Dennis Brown - 2¢ 12:07, 23 November 2021 (UTC)

Technically, it is not a vote, so 2-1 doesn't decide it. Agreed that it is mostly likely true for the restricted case of automobiles in western countries - just not sure about the general case of all types of vehicles in all countries. But I don't mind waiting a while. Cheers.  Stepho  talk  20:21, 23 November 2021 (UTC)

Again, this is the obtuse I spoke of. I know it's not a vote. I'm not new. It means you are the only one that didn't want it, so there is a rough consensus to include if possible as two did want it. Consensus is how things are decided around here. I think your "restricted case of automobiles in western countries" is overstating the case, however, as autos in almost all countries are 4 stroke, particularly in the era of Paris Accord and the Kyoto Protocol. The same is true for motorized equipment used for construction, etc. In parts of the US, 2 stroke are flatly illegal. Even in India and China, virtually all autos are 4 stroke, and that counts for a sizable chunk of the global population alone. I'm not quite as US centric in my estimation as you keep trying to tell me I am. Dennis Brown - 2¢ 20:45, 24 November 2021 (UTC)

I'm not being stubborn for the joy of it - my nature tends to not rock the boat. But you keep restricting this discussion to just cars. The claim is that 4 stroke engines are the most common for all motorised vehicles. A golf cart is a motorised vehicle, a ship is a motorised vehicle, a jet plane is a motorised vehicle, a 2-stroke motorbike is a motorised vehicle, an electric car is a motorised vehicle, etc. The claim and the support simply don't line up.

I know you've been here a long time and you're one of the editors I trust to normally do the right thing. That's why I'm a bit confused about why you're using such a weak reference to support such a bold claim. I also know how consensus works. It's about discussing reasons. I've given my 2 reasons (counting all regions, counting all types of motorised vehicles). But you've barely touched on the region issue and haven't address the type issue at all.  Stepho  talk  21:39, 24 November 2021 (UTC)

You need to go back and read the discussion more closely. I haven't restricted it to anything. Autos are simply ubiquitous; they serve as one obvious example. And if you go look up "vehicle", you will find that ships can be included, but are generally not. The word vehicle generally refers to land only. Not my opinion, but the dictionary definition. As for electric cars, they would be neither 4 nor 2 stroke, so irrelevant for the statement, however, it would be noting elsewhere how they are displacing 4 stroke motors. Another comparison that adds perspective. I haven't touched on the region issue because that isn't the focus. Establishing the relative numbers, globally, was the goal. Further in the article, absolutely plenty of room to touch on which countries buck the trend, or where the numbers/ratios are different. Feel free to actually add content. Sources are quite difficult, I've discovered, as I've poured through dozens to get actual numbers with no success. If I found 4 was less common, I would obviously change the content to reflect that, but I haven't found anything better than is currently used. As it is the Thanksgiving holiday through Sunday, I expect to be rather busy with family, but don't mistake that for me forgetting. They are just more important that a citation. Dennis Brown - 2¢ 23:25, 24 November 2021 (UTC)

Respectfully, I disagree with almost all your points in your last comment but I don't mind waiting. Enjoy the holidays.  Stepho  talk  10:12, 25 November 2021 (UTC)