Talk:Carburetor/Archive 1

Removal

I removed this:

"Claims are made to super-carburetor technology (should start new entry) that gives much higher performance given the same engine. Purported methods include vaporization, plasma, fuel cracking. Supposedly the 'powers that be,' especially the fossil fuel interests, snuff this technology in order to keep their preeminence. A collection of such stories would make for interesting reading. For sample coverage see: http://FreeEnergy.GreaterThings.com/Directory/Transportation/"

This may well be of interest, but in its current form is not encyclopedic, and to be honest sounds like a conspiracy theory. However, some mention might be worth putting in if it is researched properly and written up appropriately. GRAHAMUK 07:17, 5 Dec 2003 (UTC)

Sounds like nonsense to me, at least. --Morven 08:54, 5 Dec 2003 (UTC)

Me too, frankly. The article starts off sort of interesting, but gets increasingly wild, with accusations of foul play trying to suppress the scientist's "work". It's also a giveaway that he had to self-publish to get the information out there because of pressure by "vested interests". More likely rejected by peer review because it was B/S. The paranoia and other personal stuff creeping in makes it seem like a conspiracy theory to me. My feeling is that if such a thing were true, the manufacturers would be falling over themselves to refine it and get it to market - the first one to make a 140 mpg car would clean up and drive the rest out of business. There is no benefit to the car producers to keep making gas guzzlers if there was an alternative - i'm not even sure that this benefits the oil companies that much, especially as the reserves start to run out. GRAHAMUK 10:39, 5 Dec 2003 (UTC)

Especially since it would be such an easy way out under pollution laws. I don't think they'd go to the huge effort and expense of developing, say, hybrid cars if such an 'easy' technology could be achieved. Yes, powers-that-be and vested interests CAN keep things suppressed, but not forever, and not when there are other vested interests working against them. --Morven 15:49, 5 Dec 2003 (UTC)

Reason for revert

was that text was removed without assessing consequence for the way the article read; it left statements that seemed odd without the deleted text. If repeated mentioning of fuel injection is needed, the second mention, not the first, needs to go. —Morven 07:20, Jun 12, 2004 (UTC)

Lead alternatives

The theory about lead as an defensive measure against catalytic conversion would require some support concerning the availability of lead alternatives as an anti-knock agent. Since lead was first banned, some of the alternatives that came into use have generated negative clouds. What was the alternative to lead in the first place that it could be specially chosen with a devious agenda?

Exception

I have to take exception with this portion-

"Constant depression - the jet is varied to alter the mixture. "

-Constant depression refers to maintaining a depression automatically by using a sprung and weighted piston in the carb while the throttle only indirectly controls the opening.

"The commonest carburetor is the Variable Choke (Constant depression) type as exemplified by the SU."

-Commonest? Youd be hard pressed to even FIND one in North America. Also a variable choke does not mean constant depression.

-The throttle slide controlled directly by cable or link is variable choke but NOT constant depression.

-Constant depression always has 2 throttle mechanisms, one directly controlled by the operator and one automatically controlled by engine vacuum and gas flow. --=Motorhead 19:44, 1 Apr 2005 (UTC)

Don't like it change it, but don't forget the global nature of things and get hung up on North America alone. I shoudl have qualfied the statement, I will do now. GraemeLeggett 12:47, 2 Apr 2005 (UTC)

North America alone? Dude, this is an article about cars. Most of the world's proven metal reserves are contained in American car dumps.

strangler

Isn't strangler more of a British term? Any Brits out there? Gzuckier 14:50, 26 August 2005 (UTC)

Its a term that was in use in the 1950s. GraemeLeggett 14:54, 26 August 2005 (UTC)

One of the first patents

Hello! I have added one of the first patents for the carburettor in the list. For the first time about this carburettor has written Donat Banki in the work "Theory of the gas engine" (16.02.1893). Alexey Markov, Russia

But the article begins with this:

"It was invented by Karl Benz before 1885 and patented in 1886"

If Banki filed a patent too, then it may have been an independent invention, or simply a variation of the basic carburetor concept.

JohnSawyer (talk) 19:19, 26 February 2008 (UTC)

Link to jet

The article contains the sentence "Constant depression — the jet is varied by the air flow to alter the fuel flow", but unfortunately jet is a disambiguation page, and I can't figure out how to fix it.

This article defines a specialist sense of the word jet farther below: "small brass screws with finely calibrated holes, referred to as jets".

I would have reworded the article so that the link to jet instead referred to the definition given below, but I wasn't sure the same sense of the term was intended in both places. Could someone with knowledge in this subject fix up this link ambiguity? Vslashg (talk) 23:48, 5 April 2006 (UTC)

It is meant in the same sense but I dont know how to link to a part of the same page--=Motorhead 12:52, 14 April 2006 (UTC)

Perspective of a neophyte

I'm trying to learn about engines and thought wikipedia was a good place to start. The article you get by looking up "internal combustion engine" is fantastic. This article - carburettor - frankly stinks in comparison for my purposes. It is written as if to provide basic information for ignoramuses but then proceeds to be extremely long, unclearly written and totally lacking in diagrams. We need diagrams! Just a simple labelled line drawing would make all the difference. Other things: don't alternate terms - call it a "butterfly valve" OR a "throttle" - alternating just adds to the pain of wading through all the complexities; provide little summaries at the start of each section on the lines of "this part enables the carburretor to function by doing this" - it would make all the difference. I appreciate there's a lot to say and much of it is complex, but if the aim is to actually inform (rather than simply providing material for experts to disagree about) it needs serious rewriting.

Thanks for reading - I hope you don't mind my letting off steam a little!

Thanks. This is exactly the kind of feedback we need. Gzuckier 19:30, 30 May 2006 (UTC)

Etymology

The article could use an etymology of the word. PeepP 21:08, 4 June 2006 (UTC)

Carburetor images

I have now drawn and uploaded to this article a diagram in cross section of a basic Carburetor. If there are any problems with the inclusion of this image or the artwork itself please let me know here. Thanks. --WikipedianProlific^(Talk) 17:21, 13 July 2006 (UTC)

That's very nice work, WP, and very appropriate to this article. Thanks for posting it. I have replaced the previous carburetor photo (which vaguely showed what could only be described as part of a car engine) with a dual-view image of a more common type of carburetor, with nomenclature. Scheinwerfermann 18:40, 16 July 2006 (UTC)

Thanks Scheinwefermann, as a quick update I've also done something similar for fuel injection to achieve some level of standardisation and comrability between the two articles. --WikipedianProlific^(Talk) 20:13, 16 July 2006 (UTC)

Actually, on second viewing I see a couple of things that could use a bit of improvement on your carburettor diagram. You've omitted the jet, which should be in the very close vicinity of what you've ambiguously labelled the venturi. Scheinwerfermann 20:38, 16 July 2006 (UTC)

I've clarified this on the diagrams description. I have deliberately omitted some detail to avoid cluttering the drawing. I was trying to keep it so that a lay person could look at the diagram and basically figure out the fundamentals of how it probably works. I think that was achieved but we'll see. --WikipedianProlific^(Talk) 12:32, 22 July 2006 (UTC)

Oop, this is not as good as before. "Fan-assisted air intake" does not exist; that device at the top there is a fairly good graphical representation of an air cleaner, but there are no fans involved. That label's gotta go. My previous objection remains; your "venturi" arrow points to what is properly labelled the jet. The venturi is the narrowed area in the carburettor's throat. Scheinwerfermann 16:52, 22 July 2006 (UTC)

Seeing as the air intake was a major problem I've altered the diagram. I don't generally do this but it seemed nessessary here. If your still seeing the old image go to the images location: and press ctrl + F5 in internet explorer to reload the image and remove it from the cache. I hope this satisfys the requirements. --WikipedianProlific^(Talk) 18:59, 22 July 2006 (UTC)

Yep, that's much better! My only gripe now: No label for the venturi. Can't you please add an arrow pointing to the hump opposite the one drilled for the "jet"? Scheinwerfermann 20:03, 22 July 2006 (UTC)

I have replaced the drawing. Now it labels the venturi, has a throttle that actually allows flow, a fuel valve that looks workable, and gone is that "gas" label that annoyed. Thanks to you all.Cuddlyable3 15:01, 7 February 2007 (UTC)

Much better! Thanks. --Scheinwerfermann 16:47, 7 February 2007 (UTC)

I have reverted to my old version of the drawing as the new one was not up to wikipedia standards. I've made changes to my original diagram to bring into line with Scheinwerfermann's suggestions. I hope this new version is satisfying. Any problems, please drop me a message. WikipedianProlific^(Talk) 02:13, 18 March 2007 (UTC)

"Catalytic Carburetor" Section

I tried to clean up this section by removing some extraneous information and by making some of the relevant information more concise and straight forward. The section was simply being used to attempt to bolster the notion that superior carburetor technologies have and continue to be suppressed by corporations. There is simply no factual basis to make such a claim. The previous author made that painfully obvious by including no sources of any kind.

Personally, I'd remove this entire section altogether. As far as I can tell, the catalytic carburetor was a little used and now completely obsolete technology.

rluzinski

Before carburetors

The carburetor was invented in 1893 and it was later replaced by fuel injection. What technology did the carburetor replace?--[84.231.94.22]

Since many of the first internal combustion engines were diesel, my guess would be more primitive fuel injection or some other form of fuel mixing (when necessary - hydrogen and other gaseous fuels would not require mixing), but this would be a useful thing to have in the article. Perhaps another question would be types of fuel; when did Gasoline start being used? --Justfred 23:21, 6 October 2006 (UTC)

Directing the air through the float chamber. See German article version. Arnero (talk) 11:30, 10 March 2009 (UTC)

Colortune improper reference

Ways to check carburetor mixture adjustment include: measuring the carbon monoxide, hydrocarbon, and oxygen content of the exhaust using a gas analyzer, or directly viewing the colour of the flame in the combustion chamber through a special glass-bodied spark plug sold for this purpose as Colortune (c). The Colortune is a product patented by Istavan Szilagyi that has been around since at least 1971 when I bought mine (and it was selected by the Design Centre London). The Colortune is well established among engine tuners, as shown by 2460 "hits" in Google today. Yahoo Search finds even more hits, I won't bore you with the huge number of them, and it seems that the neologism-verb "to Colortune (an engine)" has entered the language. AFAIK there is no alternative or equivalent to the Colortune. It seems appropriate to name the Colortune by its given name in the section on Carburettor Adjustment so will someone suggest how that should be done if the text as Colortune (c) above is somehow improper?Cuddlyable3 13:50, 8 February 2007 (UTC)

Yes, I'm aware of the Colortune. However, unless/until there is a Wikipedia article on the device, it is inappropriate and unencyclopædic to make reference to it. In addition, © is not the correct mark. Published works of intellect and/or creativity (printed, recorded and/or electronically coded) are subject to copyright. Tangible products and their brand names are not. The appropriate mark may be ™, or it may be ®, or it may be one of a few others, but it is not ©. Furthermore, your assertion that "to Colortune (an engine)" has entered the language would need a great deal of support in order not to fall afoul of WP:NOR. Perhaps you wish to be bold and initiate a Colortune article; that would be a good start. --Scheinwerfermann 16:10, 8 February 2007 (UTC)

1) Scheinwerfermann, your assertion that "unless/until there is a Wikipedia article on the device, it is inappropriate and unencyclopædic to make reference to it" needs more support than just your statement, which is merely defending your own act of censorship. Is this an edict that prohibits any reference to any device not already having a dedicated Wikipedia article? It seems sadly plain that you don't wish to respond in any constructive - shall I say encyclopædic? - way.

2) In the UK Colortunes are packaged as "Gunson's Colortune" with an enclosed warning about "protected by world-wide patents" but I see no sign of a ™ or ® or © anywhere that one would expect them to be asserted for the word Colortune.

3) I did not assert that "to Colortune (an engine)" has entered the language, as you falsely attribute to me. What I did was to observe (that is subjective and allowed, even encouraged, on this Discussion page) that it SEEMS (implicit: to ME it seems) that "to Colortune (an engine)" has entered the language. You may click on http://www.gadgetjq.com/ctune.htm to see someone (not me) using it that way. You may also notice that usage is an orthodox extension of the common English verb "to tune". Unless/until someone wants to put a statement about the usage "to Colortune" on the page you have nothing to say about it.Cuddlyable3 19:33, 3 March 2007 (UTC)

Cuddlyable3, I'm not interested in a pissing contest. This is Wikipedia: Go create an article on the Colortune, which is an interesting and unique enough device that it'll easily support an article longer than a photo-illustrated dictionary entry. Once that article's in place, even in skeletal form, it'll be a terrific link off carburetor. --Scheinwerfermann 03:14, 4 March 2007 (UTC)

Scheinwerfermann thank you for informing us that this is Wikipedia. That seems to be the limit of response of which you are capable now that your officious act of censoring content has been questioned. BTW you are not in a position to command ("Go create an article...") anyone and you need to be aware that nobody has invited you to competitive urination.Cuddlyable3 16:02, 6 March 2007 (UTC)

No good reason has been given for not mentioning the "interesting and unique" Colortune. This is now done with a footnote link to the manufacturer's on-line manual. That way respects any proprietary rights without unnecessary advertising.84.210.139.189 19:41, 9 March 2007 (UTC)

The above is hilarious. I applaud Cuddlyable3.—The preceding unsigned comment was added by 66.19.201.59 (talk • contribs) 02:56, 2007 April 2.

Why do we need an accelerator pump?

The greater inertia of liquid gasoline, compared to air, means that if the throttle is suddenly opened, the airflow will increase more rapidly than the fuel flow, causing a temporary "lean" condition which causes the engine to "stumble" under acceleration (the opposite of what is normally intended when the throttle is opened).

I read the above and want more explanation. Is the temporary lean condition because:

- the airflow accelerates but the droplets already in it get left behind?

- the fluid flow of the tiny column of fuel inside and immediately behind the main jet takes longer to accelerate than the air flowing past?

- there is a temporary pressure drop in the carburetor vortex and the Bernoulli effect somehow draws less fuel from the jet?

I think all 3 ideas above are unconvincing or plain wrong and that is why I hope to see a clearer explanation.Cuddlyable3 22:20, 17 March 2007 (UTC)

The temporary lean condition occurs for the reasons originally stated, the inertia difference between the air and fuel flows. Also the rise in pressure in the manifold causes less of whatever fuel is in the manifold to evaporate or evaporate more slowly. Fuel is added by the accelerator pump to cover this transient condition until the fuel system catches up.--=Motorhead 00:12, 18 March 2007 (UTC)

The reason I am doubtful about the postulate that "the fluid flow of the tiny column of fuel inside and immediately behind the main jet takes longer to accelerate than the air flowing past" is that it implies one could eliminate the need for an accelerator pump by arranging for the main fuel jet to be not a tube but a hole in a thin wall of a large fuel reservoir, thus having negligible inertia in its delivery. Motorhead, your additional comment about evaporation speed in the manifold does not seem to concern the fuel/air mixture ratio, unless you mean that the nominally stoichimetric aerosol-fuel/air mixture being delivered by the carburetter tends temporarily to separate out. The accelerator pumps that I have seen deliver a straight jet of liquid fuel with no apparent design to atomise it.Cuddlyable3 12:58, 20 March 2007 (UTC)

Your thoroughly confused interpretations in your first question in this thread, and your partially confused claim directly above regarding evaporation in the manifold not influencing fuel/air ratio, make it seem quite doubtful you've enough knowledge to be critiquing the veracity of carburettor operational theory. IOW, just because you don't or can't understand something doesn't mean it's wrong. That said, the search for a single reason for the need of an accelerator pump is futile; there are several reasons why such a pump is called for, and they've been covered in this discussion thread and in the main article. Your guess above is correct: When the throttle is opened, manifold absolute pressure rises. As you (should) know, increased pressure tends to cause vapourised liquids to condense, and atomised droplets to agglomerate. It is also correct that the liquid fuel, having greater mass than the gaseous air, has greater inertia and therefore fuel flow does not increase as quickly as airflow when the latter is abruptly increased. Your "hole in the thin wall of a large fuel reservoir" idea is without merit, for it would not significantly alter the inertial difference between the liquid fuel and the gaseous air, and it would preclude the use of most of the fuel distribution aids that contribute significantly to the carburettor's ability to provide good starting, running, and driveability characteristics. Accelerator pumps are quite simple, dependable, and adjustable; it would be thoroughly disadvantageous to replace them with your idea. As to the accelerator pumps delivering a straight jet of liquid fuel with no design to atomise it: Yes, correct, that's how they work. And work they do! I'm not sure what your point is here. --Scheinwerfermann 14:59, 20 March 2007 (UTC)

How can evaporation change fuel/air ratio? Cuddlyable3 12:10, 23 March 2007 (UTC)

No answer seems available because of course neither evaporation nor condensation change the ratio of the ingredients.

"When the throttle is opened, manifold absolute pressure rises" is correct. And it stays at the new pressure until the rpm increase, which may not happen for a long time. The carburetor is intended to serve also that new manifold pressure indefinitely, so the transient aid of an accelerator pump can't help it do that.

Since neither you Scheinwerfermann nor the sentence that introduced this thread make any distinction between the inertia of the fuel in the jet and the inertia of the fuel after it leaves the jet, my "hole in the thin wall of a large fuel reservoir" idea has the merit of getting us to think about clarifying which fuel inertia we are talking about. Since the idea amounts to not much more than a very short main jet I see no good reason for you to object that "it would preclude the use of most of the fuel distribution aids that contribute significantly to the carburettor's ability to provide good starting, running, and driveability characteristics".

In connection with Motorhead's preceding post about slowed evaporation of the fuel, I wondered whether an accelerator pump would more usefully deliver a spray rather than a compact stream. Fuel injectors do that.Cuddlyable3 18:28, 27 March 2007 (UTC)

---

My point about manifold pressure rising and slowing the evaporation of the fuel was that this effect is an ADDITTIONAL reason for the needing an accelerator pump. The EFFECTIVE fuel/air ratio leans out even though there is the correct amount of bulk fuel present; it is of no use if it doesn’t evaporate. Accelerator pumps definitely ARE designed to atomize the fuel. The fuel jets squirt directly into the venturi (exactly where the main jet injects its fuel) where it is violently accelerated by the air flow. Many carbs have been built without accelerator pumps. The Gast/Lectron motorcycle racing carb being a shining example, delivering superb power and responsiveness. ( http://www.fastbygast.com/Catagories/Products/Description/How%20it%20works.asp) By careful attention to the responsiveness of the jet circuits, it is possible to get first class performance without using an accelerator pump.--=Motorhead 23:45, 20 March 2007 (UTC)

The fuel/air mixture forms in two stages: 1) Fuel is drawn from the jet into the airstream by the Bernoulli principle. 2) The fuel aerosol is accelerated by friction with the airstream. This acceleration takes a finite time, due to the finite mass of the fuel, so in the final fuel/air mixture, fuel is associated with an older part of the airstream than it first entered. This association-lag is innocuous during steady-throttle operation, but if the throttle is suddenly opened the amount of fuel is temporarily wrong (i.e. too weak mixture) for the new faster airflow. This temporary "lean" condition can cause an automobile engine to falter under acceleration.

The above explanation is my present understanding. In it, the inertia (mass) of the air is not considered as a factor. I believe it is irrelevant and that the same things would happen if the air were replaced by a fluid having same or greater mass than the fuel.

Motorhead, we are talking about the fuel/air ratio, with no distinction about the state (droplet - aerosol - atomised - evaporated ?) or combustability of the fuel, which should be separate issues. Thank you for giving the link to a carb that seems to need no accelerator pump. I mention the venerable SU carburetor as another example.Cuddlyable3 11:58, 21 March 2007 (UTC)

There is nothing wrong with the explanation you have quoted other than it is incomplete and thus can be misleading. The effect described is presented as a major factor when in fact it is a small modifying influence. Working in the research department of Homelite I have used a Strobotach to look down the intake of a chain saw running at full throttle on the dyno. It could be seen that the instant the port begins to open the fuel is smashed into an aerosol and drawn in with the air with NO apparent delay in moving with the air. On the other hand the instant the port closes and air flow stops, the fuel can be seen to continue flowing out of the main jet in a stream that crosses the venturi and hits the far wall until the next inrush of air hits it. This shows the inertia of the fuel in the jet well. Just as it resists stopping it resists accelerating. The main jet will establish an average flow that matches the average air flow under steady running conditions. Under those conditions the flow of fuel from the main jet is very nearly constant and NOT intermittent as might be assumed. If the explanation you have quoted were the whole story then engines with one carb per cylinder would barely run at all with a heavily stratified and patchy charge.

As far as air/fuel ratio goes, consider an engine starting in sub zero weather. Even though the fuel/air ratio is correct, the engine fails to start unless there is some kind of enrichment added. So the EFFECTIVE fuel/air ratio is all that matters. So the state is an important factor. Yes there is some association-lag. Yes there is a loss in evaporation and Yes there is inertia lag in the fuel jet. Add it all up and you need an accelerator pump to fill in the gap on certain types of carburators-Those which have long main jet passages and which do not expose the main jet to vacuum signal unless and until the throttle is opened. It happens that of these factors, the inertia lag is the most prominent.--=Motorhead 00:01, 22 March 2007 (UTC)

Motorhead thank you for describing research you have done. Air has mass (about 1.2g/L at sea level) and liquid gasoline has mass (I guess about 900g/L) so neither substance can be accelerated instantly, and Newton's second law is obeyed. Similarly, air flow in the venturi cannot stop the instant the port closes. Could the continuation that you observed of fuel to flow from the jet after the port closed be due to the inertia of the moving (invisible) air column at least as much as that of the fuel column in the jet? I gather that you have built a carburetor and so could quote actual numerical volumes of the two columns to answer this question.

Having a volume of compressible air between the carb(s) and the intake port(s) gives a smoothing of the venturi flow that aids efficient carb design, but that is a wider subject than the title of this thread. The engines with one carb per cylinder that I know of are either 1) small utility engines with no special demands on acceleration, and 2) high performance engines in sports or racing vehicles (see Image:1961 Ferrari 250 TR 61 Spyder Fantuzzi engine.jpg). Here the trumpets added to extend the intake columns are obvious.

I agree that having stoichimetric fuel/air ratio alone does not give easy cold starting. However the sentence that introduced this thread does not touch on that, nor do I see definitions of "effective" contra "ineffective" fuel/air ratios.

Where we can identify several causes for an event, in this case the temporary lean condition, we must be inquisitive about their relative magnitudes before settling on a conclusion about which one is most prominent. To what has been mentioned I add the finite lag of the float + valve assembly to adjust to a changed fuel flow demand.Cuddlyable3 13:57, 23 March 2007 (UTC)

The flow observed from the main jet was not due to air flow because it was unperturbed, squirting cleanly straight across the bore, much like a water tap running at the lowest setting. The intake system length of 2 inches on the chainsaw means that the wave activity has little strength. Additionally, at the closed end of the intake system, there is little flow due to wave activity (regardless of how strong it is) because the downstream volume is so small. (This is one reason you would like to have the carb close to the valve and add the required length with a trumpet or velocity stack on top rather than have the carb at the outside end where it will recieve the strongest pulsation flow.)

There are cases where the effect you mention occurs- Longer intake systems with the carb at the inlet end. In those systems the wave activity will definitely draw fuel out due to air sloshing back and forth while the port is closed. I mentioned this chainsaw experiment to show the inertia difference in real terms.

When I said Effective it should be taken as the fuel /air ratio that is actually in effect. The un-evaporated fuel does not take part and so the mixture is “Effectively” lean, even though the presence of the proper amount of fuel shows that the Actual fuel / air ratio is correct. The engine behaves almost exactly as if it were lean.

Since gasoline has 780 times the density of air. It does seem obvious that there will be a large discrepancy in response between the two substances, especially at very high speeds.--=Motorhead 01:12, 24 March 2007 (UTC)

Motorhead, I understand you interpret what you saw as: the airflow stopped instantly and then fuel continued to squirt for a time into the still air. I did not see what you saw and my problem with the interpretation is my knowledge that air cannot stop instantly, and is impossible to see directly. Therefore I want to look at actual masses in acceleration/deceleration that are involved. Movement of the air mass causes movement of the fluid mass. Gasoline indeed has about 780 times the density of air but mass = VOLUME x density. I am still hoping you will provide volumes to complete that equation for the two masses involved. Alternatively, please tell me the diameter and internal length of your main jet!

We must not have two conflicting definitions of the same word "LEAN". It is defined relative to stoichimetric air/fuel content ratio both in Wikitionary and in our Carburetor article by the sentence "Too much fuel in the fuel-air mixture is referred to as too rich, and not enough fuel is too lean." I contend that merely putting lean in between quotes as in the sentence that introduced this thread ("temporary "lean" condition") is an inadequate way of indicating that one has changed to a different definition, namely what you have described as "the fuel/air ratio that is actually in effect". That confuses observed/interpreted combustion result with prescription.

What you call wave activity, which I might understand as a pressure wave travelling at the speed of sound in the compressible air, has not been described in the sentence that introduced this thread. Does it need to be?

Newton's Laws are sometimes less than obvious where a fluid-becoming-a-vapour and a gas of very different densities and volumes interact.

(I think the first concern of the example Ferrari engine designers was to obtain maximum airflow by having as big inlet ports and as short and wide tube connecting each one to a carb venturi as they could manage. After that, the added air column mass in the trumpets gave them some deliberately tuned resonance that strengthens the pulsating inflow for a particular intended range of engine speed.)Cuddlyable3 01:07, 25 March 2007 (UTC)

The diameter of the carb bore was about .750 inches and the length of the carb throat plus the port length was 2.5 inches. The diameter of the main jet was about .020 with a length of .375 . You can see some of this wave activity in action if you download the freeware engine simulator from Lotus http://www.lesoft.co.uk/

Of course the air does not stop INSTANTLY but in relation to the fuel flow and engine cycle it stops so quickly as to have no significant effect (on that particular engine). The fuel flows nearly constantly throughout the cycle showing the inertia of the fuel.

--=Motorhead 15:19, 25 March 2007 (UTC)

Motorhead, thank you for providing dimensions. I calculate that in your example engine the ratio of volumes of air/fuel columns is 9375. The mass of fuel to be acc- or de-celerated in the jet is only 1/125 of the mass of moving air.

The Lotus engine software is interesting especially the documentation which I am reading. It seems to deal with steady-state models that do not relate directly to accelerator pumps. This handbook: http://www.grapeaperacing.com/GrapeApeRacing/tech/inductionsystems.pdf describes the technology.

In the case of Helmholtz resonant inflow (at the apropriate rpm) the airflow at the entrance has constant pressure and its speed varies in a sinusoidal cycle, while the air pressure at the inlet port varies sinusoidally. Cuddlyable3 20:21, 25 March 2007 (UTC)

Carburetors in aircraft

"Most of the piston engines in small aircraft are carbureted." has been added by Ve2jgs. However I think the "toilet tank" fuel reservoir arrangement with a float valve described in the article is impractical in an aircraft which is liable to loop the loop.Cuddlyable3 13:01, 17 April 2007 (UTC)

I have removed the above sentence because it is not clear whether it means "most" aircraft flying today, or "most" aircraft that have been designed.Cuddlyable3 10:48, 30 April 2007 (UTC)

I am certainly aware of some early aircraft that were indeed unable to loop the loop due to gravity fed carbs, or at least such a manoeuver was very risky. For example the WW2 era British aircraft like the supermarine spitfire had to perform a fairly complex manuever known as 'peeling off' in order to descend, as to enter into too steep a dive would starve the engine of fuel causing it to crash. The tip of one of the wings is dipped down causing the aircraft to peel away in that direction diagonally downwards, meanwhilst the nose is moved upwards or downwards causing the aircraft to slow (giving it the appearence of moving backwards but obviously it isn't). The wings are then levelled and normal flight resumed. You can see the manoeuver in this clip at time 1:13 http://www.youtube.com/watch?v=9Kkv1-jYWXI&mode=related&search=. Equally, in those days I understand that when the engine stopped running (e.g. from fuel starvation) it was virtually impossible to fire it up again mid flight. By contrast, german and some US aircraft of the era were fuel injected to overcome the problem, giving them something of a technical advantage. I believe this is seen in aircraft such as the German Junkers JU87 dive bomber and the US B-29 Superfortress. In the same movie clip at around 1:25 you can see a german plane diving at an extreme angle which a British plane of the same age simply couldn't have done. I should think these days though that surely most modern aircraft will have overcome this? But then as I've previously stated my knowledge on carbs is extremely little, fortunately my knowledge of aircraft is slightly better but not much. WikipedianProlific^(Talk) 15:34, 17 April 2007 (UTC)

Contradiction

At the beginning of the article, Karl Benz is cited as the inventor of the carb, while near the end a Hungarian inventor is said to be the inventor at a later date. Which is correct? gpans (talk) 08:43, 30 December 2007 (UTC) Yeah, I noticed this too. Please fix.172.167.60.152 (talk) 21:08, 6 January 2008 (UTC)

Multiple carburetor barrels

Zaq1qaz, your reinsertion of unsourced, POV original research in the caption for the image in the multiple carburetor barrels section is not appropriate. Remember, the standard for information in Wikipedia articles is not "truth", but verifiability, and assertions — especially those that can reasonably be challenged — must be supported with citations from reliable sources. It doesn't matter what you or I or anyone else knows or thinks he knows, it matters what we can prove per Wikipedia's requirements. Please try not to take it personally when text you've added to an article (or text you think is especially nifty for whatever reason) is modified as part of an effort to improve the article according to Wikipedia's standards, and remember to keep your comments in edit summaries relevant to the material at hand. Personal attacks such as you made, like other uncivil behaviour, are not OK. Please also take a few moments to click the links embedded in this comment to learn more about how to make your contributions more likely to remain part of the article as it evolves and improves with the effort of all who choose to participate. Remember, Wikipedia is a coöperative effort, not a competitive one. If you carry on inserting unencyclopædic text and not engaging on article talk pages, you run the risk of being blocked. Thanks for choosing instead to coöperate. --Scheinwerfermann (talk) 16:39, 7 February 2008 (UTC)

Update: Zaq1qaz, thanks for providing an appropriate citation. I've done a cleanup for clarity, and moved it out of the photo caption and into the article text where it belongs. --Scheinwerfermann (talk) 17:07, 7 February 2008 (UTC)

I put it back in the photo caption. Please copy the wiki rule that says important, and referenced information, cannot be placed in a photo caption. If you can't, leave it alone. Thank you. Zaq1qaz (talk) 17:55, 7 February 2008 (UTC)

Please see WP:CAP, particularly the subsection on succinctness, for a detailed overview of how best to caption images in Wikipedia. The caption's job is to describe the image. Detailed and referenced discussion of the subject matter belongs in the article text. --Scheinwerfermann (talk) 18:07, 7 February 2008 (UTC)

NEXT time, please insert a request for a citation before willy-nilly deleting something. You know, a FACT tag. THEN, you can discuss things further on this page. DO NOT just delete stuff. Zaq1qaz (talk) 18:02, 7 February 2008 (UTC)

I encourage you, as a new editor, to review the links at the top of this thread to get up to speed on how best to work coöperatively on Wikipedia. --Scheinwerfermann (talk) 18:07, 7 February 2008 (UTC)

Removal from auto parts category

Hooperbloob, I have reverted your inappropriate removal of a valid category tag from this article. Your edit summary (rm auto parts cat, no need to capture every last engine part) is puzzling and contrary, for the purpose of the auto parts category is to encompass articles about auto parts, and carburetors qualify as such. If you perceive some valid reason in accordance with Wikipedia policy why Carburetor should be excluded from the auto parts category, please discuss your point of view here on the talk page and obtain consensus before removing the article from the category again. Thank you for being a coöperative Wikipedian. --Scheinwerfermann (talk) 16:00, 8 February 2008 (UTC)

A couple things

Wiki's carburetor article still cites two inventors of the carburetor, without referring to the other inventor. The first paragraph says "It was invented by Karl Benz before 1885 and patented in 1886", but the section "History and development" says "The carburetor was invented by the Hungarian engineer Donát Bánki in 1893." This hasn't been changed since this was first noted above. I don't know which is true, but I'm sure someone knows. From the dates, it appears Benz invented it first, and Banki later independently invented it, but I thought there would have been more communication in Europe at the time, about such developments.

As to arguments that not much more mpg can be gotten from gas engines, because "you can't break the laws of physics", that's an ad hominem. Nobody is arguing that physics can be violated--the argument is whether we can get more mpg out of gas engines.

As to the argument about whether there's such a thing as a super-efficient carburetor, it appears there may at least be ways to make better ones (or for that matter, better fuel injection devices?):

http://seattlepi.com/local/351903_needle20.html?source=mypi

http://www.opel-p1.nl/custom/testcar/Shell%20Opel.htm

These links describe a modified 1959 Opel, in 1973, that got 376 mpg on a closed track, running at 30 mph. Though there were several modifications to the car that were impractical for average cars (super-hard tires for less friction; removal of most of the interior, to reduce weight; chain drive; etc.), the article says "The mileage from the mostly stock four-cylinder came from heating and insulating the fuel line so the gas entered the engine as lean vapor." To me, that sounds like a carburetor-related modification to make it more efficient. Maybe "super-efficient" is a term that could apply? And if heating the fuel line isn't technically a carburetor modification, then we should stop looking at carburetor modifications, and look at whatever this heating was all about, or whatever else was at play in this car. It's also possible the article's author is making assumptions about what the real factor in the car's high MPG is--it may indeed have been more due to the other modifications. As someone pointed out in the talk section of the Seattle PI article:

"The Shell eco-marathon is still running and the current (ethanol) record holder gets 8,136 mpg. It's not that we don't know how to build extremely fuel efficient cars anymore, rather it's that there is a huge difference between building a car solely designed to get high mpg on a test track, and building a car that meets all the requirements of the real world (in terms of safety, reliability, features, etc)." JohnSawyer (talk) 19:12, 26 February 2008 (UTC)

Please read up on what ad hominem actually means. I think the point you're trying to make is that there have been serious efforts to increase the fuel efficiency of internal combustion engines by making fundamental changes to the way fuel and air are combined and ingested, and that some of these efforts, in whole or in part, can reasonably be said to fall under the category of carburetion. You're probably right. Nevertheless, it would probably make significant problems to try to incorporate that information into this particular article, for several reasons. This is the article that describes what everyone knows as the carburetor, i.e., a device that atomises metered fuel and mixes it with air by means of the venturi effect.

There have been many, many attempts to reëngineer the carburetor fundamentally (as for example by employing heat to vapourise fuel, employing magnets to "repolarise" the fuel, and numerous other techniques). Some of these have been demonstrated successfully in one way or another under controlled, scientific tests, but many others have remained in the realm of the common snake-oil scam. You mention a very critical key point with your last quote from the PI article (special-purpose test vehicles vs. mass-produced all-purpose vehicles acceptable and available to the general public). I'm curious whether you've read up on Smokey Yunick's "adiabatic" hot-vapour engine.

An article dealing with what we might, per your suggestion, call "super-efficient carburetors" would likely need to be as long as this carburetor article to cover the various principles tried, the various implementations demonstrated, the ones that seem to work vs. the ones that never got anywhere vs. the obvious/exposed scams, and so forth. Because of the eccentric and colourful ways of many who have invented and presented super-efficient carburetors, and the nature of claims made, not to mention the conspiracy theories that persistently circulate around the subject of improved carburetion, it would likely be quite challenging to make and keep such an article in compliance with WP:NPOV, WP:V, and WP:RS, amongst other Wikipedia core principles. It would not be impossible, but it would be difficult. That should not stop you from being bold and starting such an article if you like (or expanding on whatever article may already exist), but if the subject of "super-efficient carburetors" were to be added to this article beyond a short paragraph with a link to the subject's own article, this article would grow unwieldy, contentious, and problematic.

Regarding the question of who first invented the carburetor, that's likely to remain problematic in the absence of definitive proof one way or the other; it is possible — rather common, history shows us — for similar or identical devices to be invented simultaneously (or almost simultaneously) even when its multiple inventors are entirely separated from one another and not in any contact whatsoever. Also keep in mind that Europe back then was very much a collection of very separate countries. —Scheinwerfermann (talk) 23:17, 26 February 2008 (UTC)