Talk:Diesel engine/Archive 2

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Diesel engine power and size

In the "Power and fuel economy" section, there's a paragraph saying that diesel engines have a lower power output than a petrol engine with the same size. This is not accurate. In Europe, in general, clean diesel engines do have a lower power output when compared to a same sized petrol engine. However, there are exceptions... BMW's diesel engines. The BMW N47 engine has a displacement of 2.0 L, but can deliver 204 PS. That 201 hp. There are petrol engines with the same displacement, that cannot deliver that much...

Also, I must point out the existence of diesel engines used in competition. The Audi R15 TDI (5.5L, 600 PS) and the Peugeot 908 HDi (5.5L, 730 hp) are evidence of this.

It's possible, with current engine technology, to make a similar sized petrol engine, more powerful than it's diesel counterpart. But reality demonstrates that there are diesel engines more powerful than a same-sized petrol engine (or even more powerful than larger petrol engines). —Preceding unsigned comment added by 82.155.143.227 (talk) 16:21, 22 June 2010 (UTC)

What many people do not realize is that diesel engines will develop a much higher peak torque than a petrol engine. They also generate the peak torque at a much lower RPM as well. Petrol engines typically develop about half (or less) torque than a petrol engine of equivalent horse power. So a 140HP diesel could outrun an 200+ HP petrol car. The engine weight is a bit of a problem though. The weight difference can even out the difference. Thaddeusw (talk) 23:41, 9 July 2010 (UTC)

You're completely wrong. Basically, because torque measured at engine (crankshaft) has to be demultiplied by the gearbox. Therefore, you can have a car with has a higuer engine-torque than another one, but less torque measured at the wheels because it has to demultiply itself much more due to it's engine running, for example, at lower rpm. This is why the horsepower is more important for racing: it's the same as speaking of energy output. Whether the energy is in form of torque or in form of "rpm" is completely irrelavant as long as you have a gearbox: you can transform rpm into torque and viceversa. Obviously, a more torquier engine could be more driveable in everyday situations but you are speaking about "outrunning" which assumes a race. In such a situation, you usually strech both engines to its max power ouput (rpm), making it irrelavant the horsepower (or torque) at its lower end. So no way a 140 bph diesel would outrun a 200 BHP petrol car, until it's gearbox configuration is totally screwed.

For example (the numbers are imaginary):

140 bph => 500 units of torque * 2000 rpm => 1:1 drivetraing demultiplication => 500 units of torque at the wheels (the wheels spinning at 2000 rpm) 200 bph => 300 units of torque * 6000 rpm => 1:3 drivetraing demultiplication => 900 units of torque at the wheels (the wheels spinning at 2000 rpm (6000 * 1 /3) Thus the latter outruns the former.

Look it from another perspective. Why a V12 6 litres engine outperforms a V6 3 litres? Because it burns twice the petrol (or produces twice the power) in the same space of time. Simple eh? Then, why a lot of people can't understand that you can burn more petrol in the same period of time by increasing the number of cilindres and displacement OR by burning it faster (more rpm)? I just don't get. It's the same thing yet people understands the former but not the latter....

— Preceding unsigned comment added by 37.14.162.34 (talk) 22:11, 18 March 2012 (UTC)

Why no mention of the Enfield diesel motorcycle? Surely it is worthy of note...? 86.14.187.220 (talk) 21:10, 24 April 2012 (UTC)Lancetyrell

Hydrolocking a diesel engine?? (Dubious)

The hydrolock page says that a diesel engine can get hydrolock from water in the injectors ... they don't have a reference showing where in literature that it does so (put a dubious tag on that page). Maybe it doesn't, maybe it does ..... (Personally I haven't seen this particular scenario (water in the fuel hydrolocking an engine) myself, although we did have an incident with a blown head gasket). 186.32.119.213 (talk) 16:50, 21 May 2012 (UTC)

It's quite easy to damage a diesel engine by hydrolocking it (a petrol engine will usually just stop instead), but you need to get enough volume of liquid in there to cause it. This is most commonly done by fording a river etc., and sucking water in through the air inlet.

If you fill the fuel tank with water, you will spray a tiny quantity of it in through the injectors. A _tiny_ quantity. Not a hope of being enough to hydrolock it. This is no more likely to hydrolock an engine with water than it is to hydraulically lock it with diesel fuel, if you turn the engine over cold and it isn't firing. There's not enough injected on each cycle, and remaining fuel or water is flushed out by the airflow fast enough to not build up appreciably.

As WP is not a reliable source, I've once again removed this addition. The fact that it's mentioned, uncited, at another article is no reason to propagate such an error. Andy Dingley (talk) 17:17, 21 May 2012 (UTC)

Images

Can someone revert the page to this revision. The "crosshead" link in the image needs to be changed to "Trunk piston", but the changing of the images sure was an improvement. 91.182.208.93 (talk) 13:09, 21 August 2012 (UTC)

Why? What advantage is conveyed?

Today you discovered the word "crosshead". You didn't learn what it means (you thought you did, you were wrong), but that didn't stop you spraying it across a number of WP articles. Now you think that adding "trunk piston" to a caption of an early MAN engine is useful. Why? What extra knowledge does this convey? Why is the trunk piston (which is, to be blunt, common as muck in IC engines) relevant to this particular engine? Andy Dingley (talk) 13:21, 21 August 2012 (UTC)

Compressor(s) needed for compression ignition

I was wondering whether a single turbocharger would be sufficient to create a high enough compression ratio/heat to ignite the fuel injected in the cylinder. The way I understand it, the compression ratio of a turbocharger is 2,5 X 10 (compression ratio of piston) = 25 (which should be high enough as we read in the article that "compression ratio is typically between 15:1 and 22:1 resulting in 40-bar (4.0 MPa; 580 psi) pressure compared to 8 to 14 bars (0.80 to 1.4 MPa) (about 200 psi) in the petrol engine. This high compression heats the air to 550 °C (1,022 °F)"

Am I correct to multiply the compression ratio's (rather than adding them up) ? And am I indeed correct in that a single turbocharger together with the action of the piston is sufficient to get allow the fuel to ignite (I'm not entirely sure as I read that Rudolph Diesel used a three-stage compressor (so basically 3 compressors) ?

If a single turbocharger isn't sufficient, let me know what needs to be added to allow the ignition to occur (ie add a screw compressor ?, or a mere Roots compressor, ...) 91.182.143.149 (talk) 07:27, 8 September 2012 (UTC)

I was wondering whether a single turbocharger would be sufficient to create a high enough compression ratio/heat to ignite the fuel injected in the cylinder.

That's called a gas turbine. If you abandon the piston, you can use a continuous combustion process (see Brayton cycle), where the cycle is spread out over space, not over time.

I have no idea if it's practical to reach auto-ignition temperatures for sensible fuels using this type of compressor. I 1) doubt it, and 2) very much doubt that it's worth it. If you have continuous combustion, then you can use a propagating flame front for ignition, you don't have to re-light on each stroke. Andy Dingley (talk) 08:15, 8 September 2012 (UTC)

history

this article does not mention herbert akroyd stuart who patented a compression ignition engine in 1890 and the first prototype was produced in 1891, these engines used an antechamber, the forerunner of the pre-combustion chamber and were the ancestors of the indirect injection engine but were not called diesels, as that is the name of the german, rudolf diesel, they were called 'heavy oil engines'.

Akroyd Stuart is already covered on WP and should certainly be part of the diesel timeline, as an oil engine, even if not a diesel, Diesel cycle, or compression-ignition engine. Andy Dingley (talk) 22:52, 8 October 2012 (UTC)

I've just removed a para on Akroyd Stuart from the lead. Coverage of his engine should:

• Make it clear that it's an oil engine, but not a Diesel cycle or compression-ignition engine.
• Not place comparisons with other things, outside the main scope, into the lead.

Andy Dingley (talk) 09:18, 12 October 2012 (UTC)

I'd agree that it's a predecessor of the antechamber diesel engine (not just the indirect injection diesel) but it isn't a diesel engine (by the way that is known and used today) and I can't see how it's a Diesel cycle. AFAICS, this is (like the modern diesel engine) more of an Otto cycle than a Diesel cycle. Who's got a P-V diagram handy? Andy Dingley (talk) 18:00, 17 October 2012 (UTC)

The article should be renamed 'Compression-ignition engine' of which the Diesel engine is just but one version. This would then compliment Spark-ignition engine. The Diesel cycle engine itself was an economic failure which was soon abandoned. Compression-ignition engine run on many different fuels not just diesel-fuel (with a small 'd') – just as Spark-ignition engines are not always fueled by gasoline/petrol (also with a small g/p). The now obsolete Diesel cycle engine only needs a mention in a sub-section. --Aspro (talk) 00:24, 25 October 2012 (UTC)

I have no objection to Aspro's suggestion. Active re-directs to the current title include Compression-ignition engine and Compression ignition engine. Dolphin (t) 04:37, 25 October 2012 (UTC)

Oppose rename per WP:COMMONNAME. There is certainly a case to be made for this, but "diesel engine" is commonly used and commonly recognised. More than this, it's recognised popularly as the compression-ignition engine, such that both terms mean exactly the same thing, rather than "diesel engine" being interpreted as "Diesel cycle engine" or "DERV fuel engine". Andy Dingley (talk) 09:13, 25 October 2012 (UTC)

Un-Oppose rename: This is supposed to be an encyclopedia. We wouldn't think about phrasing things such as : writing with a biro, hoovering the floor or putting coffee into a thermos. True : Common vernacular names for an engine fuelled by gasoline/petrol is commonly referred to as a gasoline/petrol engine, if fuelled gas, tis commonly referred to as a gas-engine, fuelled by alcohol it is commonly referred to as an alcohol engine, and so on for propane... etc. Yet I repeat: This is supposed to be an encyclopedia. We don't need articles on every type, as Spark-ignition engine encompasses all of these fuel variations for spark ignition engines. Likewise, large marine engines that are fuelled with thick tarry stuff are oil compression-ignition engines, so are cars that use diesel fuel (with a small 'd'). So are methane engines etc. Methane engines, have the highest compression ratio's of any compression-ignition engines and yet they don't use diesel fuel. Diesel fuel is a standard definition of a particular distillation fraction mix. If a marine engineer refers to a ship engine as a 'diesel' (small 'd') it is to make things simple for the plebs. So why should Wikipedia lower itself to the lowest common denominator at the expense of encyclopedic accuracy? Biro, hoover, thermos — and diesel, are 'common names' but these are not what Wikipedia:COMMONNAME#Common_names policy was raised for. This article -as a whole- misleads the reader (and isn't that who Wikipedia is aiming to inform) about the nature of compression-ignition engines. The reference (above) to WP:COMMONNAME is therefore, no more than misguided Wikipedia:Wikilawyering. The article title needs to be corrected to complement Spark-ignition engine. I.E compression-ignition engines; with 'diesel' as a historical subsection to put 'diesels' into their proper context. Then the average reader will be properly informed and enlightened. --Aspro (talk) 19:46, 28 October 2012 (UTC)

Third option, better: articles (not redirects) should exist at both pagenames. We should have one article called "compression-ignition engine" that provides an overview of all such engines, then also have an article called "diesel engine" that deals with a subset, all in keeping with the spirit of WP:SUMMARY and WP:SPINOFF. This would be parallel to how currently there is an article (not a redirect) at "petrol engine", which is duly taxonomically subordinate to spark ignition engine, both of which are subordinate to internal combustion engine. Regarding such pagenaming decisions in general, remember that taxonomy, the naming of things according to their attributes, is, in the big etic picture, akin to relational database management—many objects with many attributes, which can be queried and sorted by any of the many attributes—but yet natural language has only limited ability to do that; it must stop short at some point by lumping things together into some categories and ignoring, or circumlocuting, other categories. Classifying things etically takes a relational database, but natural language and cognition often tend to act like a hierarchical database. The WP:SUMMARY-and-WP:SPINOFF approach reconciles the two, which it does by allowing common-name-leaning encyclopedia pagenames to act like database views, which feel to the natural language speaker like comprehensible classifications, even though they are truly relational rather than hierarchical. This is also the same difference between "folders" in an operating system and "virtual folders", between folders and tags in general, and between database tables and database views. One hierarchical, the other relational. For example, consider the many attributes of engines: internal versus external combustion, spark ignition vs compression ignition, reciprocating piston vs rotary [Wenkel] vs turbine, choice of fuel (petrol, diesel oil, LNG, propane, kerosene, bunker oil, peanut oil, and a hundred other hydrocarbons)—there's no way to actually construct an encyclopedia pagenaming taxonomic hierarchy that neatly divides all engine instances into mutually exclusive categories; they overlap across many attributes. Instead, you need views—"saved queries". Which is where the third option just discussed comes in. The various articles should all connect to each other by reference, via hyperlinking, rather than attempting to hierarchically subsume each other. On the language-styling theme: The analogy to biro and hoover is not entirely apt, and has some (albeit wholly unintentional) specious appeal. There's a difference in copyediting between mere eponymousness and the undue genericization of a tradename. It's why the terms "Bowie knife" or "Pennington clamp" are perfectly acceptable for copyedited encyclopedic language whereas "biros" and "hoovering" are not. Those genericized-brand examples have readily available inherently generic names (ballpoint pen, vacuum cleaner), so in copyediting we prefer to substitute those to avoid brand preference or genericization. But in the case of diesel engines (NB small d), that *is* a generic name (albeit eponymous); there's no "ballpoint" behind it, and there's no brand-favoring or trademark-abusing involved. Only mere eponymousness. "Compression-ignition engine" is a taxonomic superset of "diesel engine", not a less-branded equivalent on the same taxonomic branch, so it's not a drop-in replacement like "insulated flask" is for "thermos". So talking about diesel engines is not actually in the same category (of brand-genericizing too informal to stand in copyedited writing) as talking about biros and hoovers. — ¾-10 17:33, 4 November 2012 (UTC)

it is a 4 stroke engine the prototype was built in 1892, its not called a diesel engine because the bloke's name isn't diesel, and the engine runs on the diesel cycle, and is the predecessor of the indirect injection diesel engine, it's called a heavy oil engine, because the fuel wasn't called diesel, a vaporiser is used as to allow for a more moderate degree of compression , Diesel's only patentable idea was to increase the pressure. In 1892, Akroyd-Stuart patented a water-jacketed vaporiser to allow compression ratios to be increased. In the same year, Thomas Henry Barton (who later founded Barton Transport) at Hornsbys built a working high-compression version for experimental purposes whereby the vaporiser was replaced with a cylinder head therefore not relying on air being preheated, but by combustion through higher compression ratios. It ran for six hours - the first time automatic ignition was produced by compression alone[citation needed]. This was five years before Rudolf Diesel built his well-known high-compression prototype engine in 1897. it is a diesel cycle and these engines will use diesel.

I know that Wiki has an anti British flavour but really to play games with the name Diesel--meaning an oil compression engine without at least mentioning the name of the first creator of such an engine --Ackroyd-- is enormously and shockingly misleading.You only need to make a reference to the Diesel engines inventor in the first sentence or so..80.98.113.13 (talk) 23:10, 7 February 2013 (UTC)

This article is about compression ignition engines, not Diesel cycle engines. These are commonly called diesel engines, so that's what the article is called.

This article must explain what compression ignition engines are. That has to be its primary goal – even beyond giving their history, or explaining what a Diesel cycle is. We certainly have to be careful about introducing other sources of confusion. One of those would be the Diesel cycle, another would be Akroyd's hot bulb engine. They both need to be mentioned and linked, but it has to be a way that doesn't risk clarity of the main theme. Certainly you don't introduce tenuous links into article leads.

Hot bulb engines don't use compression ignition. Yes, some experiments did – and they bear more relation to 1930s "diesel engines" than Rudolf's own air-blast engines did a few years later. However these were only ever experiments, they don't even have much relation to the hot bulb engines built and used so widely. I don't even know of any influence that this strand of development had on diesels in turn.

Hot bulb engines don't use the Diesel cycle, but then neither do diesel engines.

These were "oil engines", both diesel and hot bulb, yet that's not a strong enough connection to overlap their coverage.

So what are you asking here? That we slip it in under common rail injection and confuse today's readers even further, when they're looking to see how their cars work? If we had an article on History of diesel engines we could certainly put it into there, but as yet we don't. Andy Dingley (talk) 00:19, 8 February 2013 (UTC)

Merger proposal: article Egr vs scr into section Emissions

I propose that the article Egr vs scr be merged into the Emissions section of this article. Egr vs scr is currently an orphan, and its title is terrible, so it is quite unlikely to be found by anyone looking for the information. Its content would do better in this article than in its own article. Post-merge, I think the external link should be changed to a reference. - Ian01 (talk) 06:54, 15 January 2013 (UTC)

• oppose Too big a difference in article scale. It's worth maintaining coverage of, but WP:UNDUE in the broad diesel engine article and would be lost within it. If we had a specific article for diesel engine emissions then that could be a suitable merge target. Andy Dingley (talk) 10:26, 15 January 2013 (UTC)

Perhaps EGR vs SCR should not be included, (although a hyperlink could be made). The real issue at hand is that NOx emissions are not mentioned in the emissions sections, nor are hydrocarbon emissions. In my view, the emission section needs a significant overhaul. Especially since emission reduction from diesel engines has been a major research and development topic over the last two decades. Of course a lot can be said about emissions, and it can be an article on its own, but with the four lines in the present article, it is short and incomplete. — Preceding unsigned comment added by 190.221.42.64 (talk) 12:32, 19 June 2013 (UTC)

Black carbon

The article talks about the positive sides of Diesel environmentally, but research also shows that diesel engines emit a significant amount of black carbon contributing around 25% of the amount into the atmosphere. I believe that it would be worth researching and including in this article.

Here's a quick idea for content from the black carbon page. Shaded0 (talk) 06:51, 14 February 2013 (UTC)

• For diesel vehicles in particular there are a several effective technologies available. Newer, more efficient diesel particulate filters (DPFs), or traps, can eliminate over 90% of black carbon emissions, but these devices require ultra-low sulfur diesel fuel (ULSD). To ensure compliance with new particulate rules for new on-road and non-road vehicles in the U.S., the EPA first required a nationwide shift to ULSD, which allowed DPFs to be used in diesel vehicles in order to meet the standards. Because of recent EPA regulations, black carbon emissions from diesel vehicles are expected to decline about 70 percent from 2001 to 2020.” Overall, “BC emissions in the United States are projected to decline by 42 percent from 2001 to 2020. By the time the full fleet is subject to these rules, EPA estimates that over 239,000 tons of particulate matter will be reduced annually. Outside of the US diesel oxidation catalysts are often available and DPFs will become available as ULSD is more widely commercialized.— Preceding unsigned comment added by Shaded0 (talk • contribs) 06:51, 14 February 2013‎

" Outside of the US diesel oxidation catalysts are often available and DPFs will become available as ULSD is more widely commercialized" As a European I am happy to say that ULSD is already widely commercialized and DPFs are already common in new diesel cars in Europe (where the diesel car account for 50% of new car sales) (trucks, I am not sure, but will surely follow soon, with increasing demand on emissions). So the last sentence is a bit misplaced. Additionally your proposition may be a bit confusing mixing particulate matter and carbon black (or black carbon), without an explanation in the emissions article. I do believe that particulate matter and its components should be elaborated a bit more in this emissions article. You focussed on road going vehicles mainly, due to the USLD fuel, but realise that this fuel is not only low in sulphur but also in fuel ash! If I find time, I will try to type a slightly larger section on emissions from diesel engines. — Preceding unsigned comment added by 190.221.42.64 (talk) 12:45, 19 June 2013 (UTC)

Bio fuel in marine Diesel engines

I understand that bio diesel fuel is somewhat hygroscopic and is therefore not liked in pleasure marine engines — Preceding unsigned comment added by 86.145.220.187 (talk) 19:25, 27 August 2013 (UTC)