Talk:Bourke engine/Archive 1

The article is wrong part 432

Greg, I spoke with Roger Richards today; he doesn’t understand your obsession with the engine. Roger owns and operates one of the original Bourke engines that is +60 years old. Plus, he has built another that is water cooled. I have a BSE and MSE with over 20 years of experience as an analysis. Engineers don't go to college to become good writers; they go to become engineers and scientist. You have made statements about Russell Bourke that are un-factual and unsupported. The engine never went into pre-production, nor did Russell Bourke endeavor to improve the Otto cycle. The DOE paper on HCCI Otto cycle proves that with constant volume combustion an additional 50% of work is achievable. Have you published papers that disprove the DOE study? The Bourke Engine combustion occurs at constant volume. Do you have papers or data that supports otherwise? The Bourke Engine is unique, no engine cycle in the WORLD runs like the Bourke. FACT! Do you have papers or data that supports otherwise? http://www.eng.mu.edu/goldsborough/sgoldsb.DOE.HCCI.Meeting.2003.pdf http://www-erd.llnl.gov/FuelsoftheFuture/pdf_files/hccirtc.pdf What is your connection to the Bourke Engine? I’m going to change the Bourke site to reflect the facts. --68.212.29.228 (talk) 23:02, 26 November 2007 (UTC)

"he doesn’t understand your obsession with the engine." I am not obsessed by the engine. I am trying to make sure that the wiki article reflects the claims made in published sources, and current engineering knowledge.

"I have a BSE and MSE with over 20 years of experience as an analysis. Engineers don't go to college to become good writers; they go to become engineers and scientist." Engineers don't rant and rave. They discuss problems using polite language, logic and maths. Greglocock (talk)

"You have made statements about Russell Bourke that are un-factual and unsupported. The engine never went into pre-production, nor did Russell Bourke endeavor to improve the Otto cycle. " Did I really write anything about Russell Bourke at all? Check the history of the article. I agree that your second sentence is likely, I just didn't have any proof either way, so left it the way it was.

" The DOE paper on HCCI Otto cycle proves that with constant volume combustion an additional 50% of work is achievable."" True for very high peak cylinder ressures, and low power outputs. Bourke is not a constant volume combustion engine, and there are engineering problems associated with high peak cylinder pressures.

" Have you published papers that disprove the DOE study? The Bourke Engine combustion occurs at constant volume." Rubbish. Plot the motion of a scotch yoke engine compared with a conventional engine of the same stroke. Combustion occurs over 20 to fifty degrees of crank angle. see Piston motion equations for the equations for a normal engine, and a Scotch yoke is a sine wave. "Do you have papers or data that supports otherwise?" JB Heywood "Internal Combustion Engine Fundamentals" is my usual reference.

" The Bourke Engine is unique, no engine cycle in the WORLD runs like the Bourke. FACT! Do you have papers or data that supports otherwise?" Extraordinary claims require extraordinary proof. The onus is on the boosters to provide evidence in favour of the claims.

"http://www.eng.mu.edu/goldsborough/sgoldsb.DOE.HCCI.Meeting.2003.pdf

http://www-erd.llnl.gov/FuelsoftheFuture/pdf_files/hccirtc.pdf" Thanks, interesting.

"What is your connection to the Bourke Engine?" None.

"I’m going to change the Bourke site to reflect the facts." Great, that will improve the article immensely. Remember that any statements about performance will need to be backed up by publicly available references, see WP:RS. However before you do another of your shotgun attacks on the article itself why not post the claims and evidence here in the Talk page so we can go through them to sort them out? Being as we're both engineers and all. Please check out what I said about Scotch yokes, constant volume combustion and crank angle, you'll find that I am 100% right. If you don't have the skill to do that I could post the relevant graphs, but you'll believe it if you do it yourself. Incidentally if you edit the article directly at least try and put claims in the claims section, and critiques in the critiques section. Greglocock (talk) 00:04, 27 November 2007 (UTC)

Oil

The information on the oil lubrication system and many other functions of the engine are CONFIDENTAL. Watch the video(s) at http://bourkeengine.net/videoclips.htm. You’ll see no smoke in the exhaust and low recorded exhaust temperatures. The Bourke 2-stroke engine does not require oil in the fuel, it has an improved intake/exhaust cycle, and ignition occurs at TDC at MAXIMUM compression. No engine in the world runs like the Bourke Engine. ALEX... —Preceding unsigned comment added by 68.212.7.32 (talk) 02:00, 23 November 2007 (UTC)

If they are confidential then how are we spupposed to reference them? Greglocock (talk) 02:58, 23 November 2007 (UTC)

The various enthusiasts state that the lubricating oil is well separated from the combustion chamber. If so, how are the piston rings lubricated? Greglocock 12:53, 31 May 2007 (UTC)

Charge separation

The drawing explicitly shows fuel injected into the transfer port. Is all air transferred into the combustion chamber of roughly equivalent fuel/air ratio? Or is the fuel injection timed so that the fuel is concentrated into the latter part of the scavenging cycle? Greglocock 12:53, 31 May 2007 (UTC)

Slipper bearing

The slipper bearing is used for the piston ring. Slipper bearings are used in jet engines they are extremely reliable and have very long lives. This engine only has two moving parts. It’s amazing that the 4-stroke engine runs with so many moving parts, and potential for failure. ALEX... —Preceding unsigned comment added by 68.212.7.32 (talk) 00:41, 23 November 2007 (UTC)

The model that is linked to from the article clearly shows a complex rotary plain bearing. The cross section linked to, from the article, clearly shows a similar plain bearing. Is there any eveidence at all that a slipper bearing is (a) used and (b) had a long life in this application and (c) was feasible in this application - the combination of rotary and longitudinal travel is quite complex. Greglocock 12:53, 31 May 2007 (UTC)

Ideal Gas Law - Adiabatic cooling

Ideal Gas Law (P1*V1)/T1 = (P2*V2)/T2 – The temperature and volume of a gas (fuel/air mixture) is proportional. In the Bourke engine the fuel ignites when the piston is at TDC (minimum volume – highest temperature) and held there for a very short time (dwell). At BDC the gaseous (H2O vapor and CO2) are exhausted (maximum volume – lowest temperature). In other types of combustion engines, the fuel/air mixture ignites on the downward stroke of the engine, leaving as a flame and not completely burn. The Bourke engine low exhaust temperatures (100 °C) represents that complete combustion has occurred and meets ideal gas laws. ALEX... —Preceding unsigned comment added by 68.212.7.32 (talk) 00:45, 23 November 2007 (UTC)

The adiabatic cooling claim makes no sense, since adiabatic implies no heat transfer, yet you are saying the cylinder and psiton gets cooled, presumably by the gases. Why do you persist in posting things you don't understand? Greglocock 23:11, 22 May 2007 (UTC)

Greg...You are correct on the word adiabatic...go to the this link adiabatic process....and scroll down the page....a gas when it is compressed heats up...taking heat from its surrounding....when it expands it cools....both are called adiabatic, one is called adiabatic heating...the other cooling...it is the process a refrigerator usesSno2 01:11, 23 May 2007 (UTC)

Whoops....should be gives heat to its surroundings...and when cooling takes heat from surroundings....Sno2 01:57, 23 May 2007 (UTC)

I don't need to go to a link. The definition of adiabatic is NO heat transfer. Greglocock 09:47, 23 May 2007 (UTC)

Greg..I quoted some information and put links on your talk page.. adiabatic heating and cooling are terms normally used in refrigeration...probably why you are not familiar with them..

simple explanation refrigeration

Gas is compressed-heating up, energy is removed from gas (usually a blower across some coils), called adiabatic heating.

Gas is allowed to expand-it tries to return to its former temperature in the volume allowed it, since it does not contain as much energy as it previously had in that volume (adiabatic) it takes energy it needs from surroundings, cooling the surroundings-called adiabatic cooling. Total energy in system tries to remain the same.

Both are called adiabatic since the effects are caused by the system trying to return to its adiabatic state. (balance state) where no energy is trying to get in or out.

The heating is used in diesel, cooling is not usually used in IC engine....but is used in bourke.Sno2 17:08, 23 May 2007 (UTC)

Greg...OK, how about a compromise...??....no mention of the word adiabatic....will call it expansive cooling effect and link to the Joule-Thompson effect page. There is only one mention of the word adiabatic on the effect page.

No compromise is required. Remove either the heat transfer claim, or the adiabatic claim, and it makes sense. Leave them both in and it is self-contradictory. The JT effect is precisely what you don't want in an engine, since you get no work out of it. Quote from first sentence "which means that no heat is transferred to or from the gas, and no external work is extracted" Do you even try and understand this stuff? why not buy a book on thermo, and one on engines, and read it? Greglocock 22:27, 24 May 2007 (UTC)

Greg...looks like maybe selective reading to me...here is sentence from JT page... "Reversible adiabatic expansion, in which the gas does positive work in the process of expansion, always causes a decrease in temperature".

You do realize that if you continue to ignore everything I am trying to show you, that to be consistant you will have to go all over wikipedia and delete/change those references, and others...so they all agree with your thinking...??

You keep saying that the definition of adiabatic is no heat/energy entering or leaving system. I have always said I agree with that...however adiabatic cooling and adiabatic heating have different meanings and the term adiabatic is used because it is the preferred state, rest state, balanced state (called number of things) of any system and that fact is used to cool and heat by expansion and compression of a gas, a system will try to return to its original adiabatic state where energy is not moving.Sno2 00:13, 25 May 2007 (UTC)

You persist in typing nonsense. Just because you can join words together does not make your ideas valid. Adiabatic is a description of a process, not a state. Greglocock 00:57, 25 May 2007 (UTC)

Greg...it looks like both of us are wasting our time...and since no one else has jumped in on this discussion our votes cancel each other out....I understand that a subj referee can be called in to decide in cases like this....would like to call in a thermodynamics expert....do you know how to do this or should I research it...???Sno2 01:40, 25 May 2007 (UTC)

Fine, I know I am. The problem is I am using a textbook about engines, and my knowledge of thermodynamics and engines, you are grabbing quotes off the internet. Let's try it, once more, from the top. In the ideal otto cycle the expansion stroke is the one where work is extracted from the working gas. In the ideal otto cycle this expansion is assumed to be adiabatic, which means that no HEAT transfer takes place. In the real world, heat transfer takes place, so the expansion is not adiabatic. If you look at data from real engines you can compare the pressure/temperaure vs stroke, with what the ideal Otto cycle would predict. The agreement is not too bad, usually because the expansion is rapid and so there is not enough time for significant heat transfer to take place, but is not perfect. The Bourke engine is by no means unique in having an expansion cycle that is near-adiabatic, but it is not adiabatic precisely because heat transfer takes place. Now, go and find a thermodynamicist who is familiar with heat engine cycles (hopefully any thermodynamicist is), and ask him to criticise that paragraph. By the way it isn't a vote, if you are wrong I will correct you, as you originally asked. Greglocock 02:37, 25 May 2007 (UTC)

Greg...am not grabbing quotes off the internet...am mostly relying on my remembered thermodynamics...I admit I am having to do a lot of research to insure what I remember is correct and to refresh my memory....I think you probably know more about thermodynamics then I remember...however on this point I believe I am right...for this reason will attempt to get a referee to look this over. You must have seen by now that I have no problem with being proven/or shown that I am wrong....however I do not believe you have done that on this point. It may be a matter of sematics and we are misinterpeting what is being said...if so an expert would be able to inform us of this....do you know how to get a wiki science expert to look this over....???...or should I start to research how to do it...??Sno2 03:06, 25 May 2007 (UTC)

Greg...never thought about talking about the carnot cycle (duhhhh) thanks for the hint....take a look here it talks about both adiabatic and isothermic processes in carnot cycle...still want to get a referee to look...Sno2 04:30, 25 May 2007 (UTC)

Think I have figured out what may be going on....I am used to considering all heat engines from the carnot cycle viewpoint..with four equal but different steps.....working on otto cycle engines in the real world, I think you have become used to thinking in two steps...both isothermic....lumping the adiabatic steps in with the isothermic....in a conventional engine there is adiabatic expansion (cooling) going on...however in order to make full use of it the piston going down would have to keep going below BDC....not sure how you would do that....switch cams or something...???....can imagine how complicated it would get to switch from one cam to another halfway at the speed it would have to occur <grin>.....the bourke does it without changing length of piston travel....

New comment Seems pretty simple to me chaps, when the intake charge is compressed "heats up" (actually the heat in that volume of air is just concentrated into a smaller volume). If there was no fuel in the charge (and therefore no burning) the charge would return to it's original temperature when the piston returns to BDC. Because the up-stroke and the down-stroke are of equal length the process could be considered adiabatic(yes the cylinder head would absorb a little of the heat while the piston was at TDC but it's basically an adiabatic process). Now, if there is fuel in the charge there will be more heat introduced into the charge as it burns. The cannot be any more "cooling" of the charge in an Bourke engine than there is in a conventional engine because they both have equal length intake and compression strokes. The reason the exhaust is cooler on the Bourke engine is that the piston dwells at or near TDC for longer and so the air/fuel mixture has finished burning by the time it comes out of the exhaust. In a conventional engine the mixture is still burning a little when it comes out of the cylinder(this is what makes a catalytic converter work and why they are necessary). We have all heard of the benefits of higher compression ratios but the problem with a conventional engine is that as soon as the air/fuel mixture is ignited, and before it has finished burning, the piston starts to move down, reducing the compression more and more as the fuel burns. The benefit, as I see it, of the Bourke engine is that the piston dwells at TDC longer, and accelerates from TDC more slowly(due to the elimination of the effects of connecting rod angle on piston position/rate of acceleration, due to the use of the yoke assembly instead of a connecting rod) so the fuel burns more completely because it stays in a state of high compression for longer. Llichtveld 13:27, 28 June 2007 (UTC)

Disclaimer

There has been no testing performed by the government and/or the automotive industry. The Bourke Engine Project has submitted proposals to the Army for testing. Statements below about testing are inaccurate and can not be supported. ALEX... —Preceding unsigned comment added by 68.212.7.32 (talk) 00:52, 23 November 2007 (UTC)

21May2K7-Removed link to possible scam page, selling information that is available on other Bourke engine sites that are listed and selling a claimed fuel efficiency device that has been proven to be scam by both government and automotive testing services.

Aren't all links selling plans touting that the Bourke engine is a super efficient engine a scam? All scientific analysis and actual data on the Bourke engine shows it to be an inefficient engine. --DieselDude 00:03, 28 June 2007 (UTC)

Did not remove it because of the Bourke stuff on it...removed because of fuel efficiency device and other garbage on it... Sno2 02:08, 29 June 2007 (UTC)

Hey "Guy'z", Russell Bourke LEARNED and said "This engine is TOOO PowerFull to be good to itself" after buyer's failed to learn it's REQUIREMENT's ..... which included the most impotant one - ONLY FEATHER the throttle because the RPM's will follow the throttle lever .... even under FULL-LOAD ...... oop'z, I broke it, again ...... -PRiMe4u2001@Yahoo.com 11-19-2007AD

NOx Discussion

Where is the reference for the claim of nitrous oxide production problems? It's very logical and "sensible" but those who build Bourke engines say that it doesn't happen. In any event, wouldn't that be primarily a result of the lean fuel-air mixture and easily remediable by running a richer mixture and trading away the assitional fuel economy in order to gain the simplicity of design?

ANY burning process that relies on high temperatures, with excess air, will produce NOx. You will get high temperatures if you want high efficincy. If you are prepared to trade off efficiency for NOx, fair enough, but don't then try and claim high efficiency. This stuff is basic engine science, fundamental to all IC engines.Greglocock 02:08, 22 May 2007 (UTC)

If there is an excess of air and therefore complete combustion there is only one NOx produced (generic term for nitro oxide compounds) nitrogen monoxide is not produced. However nitrogen dioxide is (see this link paragraph on complete combustion and incomplete combustion) Complete combustion of nitrogen occurs whenever heat is high enough and excess oxygen is present. See complete combustion of propane here, link From above any nitrogen monoxide produced in normal engine would be produced as nitrogen dioxide in Bourke. I think we are saying the same thing...that NOx is produced...I am saying that little or no monoxide compound is produced all monoxide is combusted into dioxide, because of temp and excess oxy. The same thing is happening with the carbon...first combustion product is carbon monoxide which is further combusted to carbon dioxide. I do not think NOx should be used, as final combustion product of complete combustion of nitrogen would be nitrogen dioxide.

Sno2 04:47, 22 May 2007 (UTC)

NOx is the industry standard name for it. As you say it is almost entirely NO2. If they weren't detecting any then they either did not have excess air, or they did not have high temperature combustion, and so would not have one or both of the engine's chief claims to fame. Incidentally please don't keep adding CO2 back in as a pollutant, perfect combustion of hydrocarbons implies the presence of CO2. In modern engines with cats the amount of CO2 produced per kg of hydrocarbon burnt is constant, whetehr froma Bourke engine or any other type. Greglocock 07:16, 22 May 2007 (UTC)

Was unaware that NOx was industry standard, when I see NOx the question has always been in my head "wonder what the proportion is".......I had thought that some of the CO2 in conv engine was absorbed by cat, which would have made CO2 emission in Bourke a problem, since cat could not be used, thank you for educating me on these two things....still think that NOx and CO2 should be used, as these pages are written for general public...and some people might not be aware of what NOx represents, nor that CO2 is same in conv and Bourke.Sno2 13:36, 22 May 2007 (UTC)

Above is also the reason I have tried to use the words rather then symbols for chemical compounds and elements.Sno2 13:47, 22 May 2007 (UTC)

New Comment

My understanding of nitrous oxide production in the bourke engine is that it does not happen. This is an "explosion" engine with a flame front of over 5000 ft/sec. At the time of the explosion their is peak temperature and presure and all the fuel is consumed. The short time does not allow for the production of nitrous oxides. As soon as the piston starts "shooting" down the cylinder the expanding gasses absorb the heat that is contained in the piston and the cylinder and lowering the gas temperature below that necesary for the production of this oxide. Their is no burning occuring while the piston is moving down the cylinder, only expansion which causes cooling. This leads to the low exaust temperature of around 200F degrees.

Sno2 18:46, 24 February 2007 (UTC)

Turbocharging/Supercharging

Turbocharge is the correct term...and is done on the engine. Turbochargin is the compressing of air, prior to mixing with fuel in order to have more air mixing with fuel then under normal atmospheric pressure. This is done on the engine (see the piston that compresses the air, under the main piston where the air enters)

Sno2 21:49, 2 February 2007 (UTC)

Reality Check

"Turbocharging"? Where is the turbine?

And that bit about the slipper bearings being "key" is not true as Bourke Cycle engines have been built by the Constant Pressure using roller bearings instead. I'm all for this engine being given attention but if unreal claims are made and latter seen to be hokum then the whole design is disregarded which I don't want to see happen. The whole "Simplified Explanation" section is a parroting of what Russell claimed without the application of critical thinking. Don't get me wrong, I think Russell was an amazing engineer but he considered many things to be very important which in reality are not so, things like: building the engine without gaskets so that heat transfer was improved, how automatic transmissions are horrible (sorry but I just haven't needed to push start my truck in... well I can't remember when I needed a push start), how the engine had unlimited RPM potential (the Constant Pressure people found that to be untrue). See I do my homework. What say you Sno2? BRoys 04:34, 20 February 2007 (UTC)

Roy...I do not claim to be an expert on this engine...what happened was I tried to figure out how it worked, by going to all the web pages I could find that explained the engine...I thought and still do that Bourke and those who have played with the engine would be the experts...I thought a synopsis of what I found out would be helpful here on wikopedia....I do not have any problem with adding to or changing what I wrote...as long as it makes some sort of sense <grin>....

I think a simplified explanation is needed, since by discussions I have seen on the net about this engine, they seem to show that most people who look at it do not spend any time trying to figure out how it works....with the explanation hopefully they will take a look at what is in the explanation and look at the animation and see how it works...

I appears that any number of engine designs have stolen from or reinvented what is in the Bourke...I do not see where anyone has really improved on his orginal design...

Turbocharging....The intake air is compressed, prior to being mixed with the fuel...what do you call this other then turbocharging...??...it appears to me that this is done to force more scavaging by raising the pressure of the intake charge adding to the pressure of the exaust gasses to improve scavaging and to raise the amount of the charge that is injected...it is done without a turbine, I agree, but what else should you call this...maybe unconventional turbocharging....???....I included a link to turbocharging so that people could find out what turbocharging is and what it does...

Rollerbearings....since I could not figure out how the slipper bearings work can not really comment on another way of doing the same thing...do not know which would be more efficient...however should a roller bearing comment be included in an explanation of the Bourke engine....??...since as designed it does not use them....??....I came across some other engines that tried using other types of bearings, that had problems with distortions of rods and scotch yokes because of the shock of the detonations...maybe the comment should be "as designed the slipper bearing is the key to the engine"....???....etc.

I did not say anything about the high rpm's because I could not explain it...maybe should be a comment that it has the capability of higher rpm's then a conventional otto engine...???

I used "latching" instead of trying to explain sine wave motion in comparison to the convention parabella motion of an piston...an ideal internal combustion engine would be a square wave engine with true latching...ideally would be a graph showing conventional piston motion along with Bourke motion...time verses piston distance traveled....along with start and stop burn time for each engine with degrees.....tried drawing one up but could not find drawing program that would do it.....think conventional burn time starts about 10 degrees before tdc and stops about 40 degrees, for total time of 50 degrees....Bourke should start at tdc and continue for about half, or less, then conventional...aprox. 25 degrees....??

Thank you much for your comments, was hoping someone would come along and improve what I had written. Change what you will and if I have any disagreements will comment on them and give any arguements that I may have.

Sno2 18:07, 24 February 2007 (UTC)

Sno2 18:46, 24 February 2007 (UTC)

Supercharging

Sno2 dude: it is "supercharging" not "turbocharging" if anything and it happens in most 2-cycle engine designs. I've put a bunch of attention and time into this engine design, love it and I'm very close to building one, though diesel (that is a whole 'nother story). I'll tackle the "Simplified Explination" section soon. And "Roys" is the last name, good to have you on the page.

BRoys 06:27, 7 March 2007 (UTC)

BRoys...looking forward to your changes...probably will never build one of these but would like to know how it really works....<grin>

have fun....

Sno2 21:31, 8 March 2007 (UTC)

BRoys

You changes look good to me...only have one question.... here is my comment about latching from above discussion... Like the "latching" because many people, I think....do not understand the sine wave characteristics...

The latching is in quotes to indicate this is not exactly what is happening...

I used "latching" instead of trying to explain sine wave motion in comparison to the convention parabella motion of an piston...an ideal internal combustion engine would be a square wave engine with true latching...ideally would be a graph showing conventional piston motion along with Bourke motion...time verses piston distance traveled....along with start and stop burn time for each engine with degrees.....tried drawing one up but could not find drawing program that would do it.....think conventional burn time starts about 10 degrees before tdc and stops about 40 degrees, for total time of 50 degrees....Bourke should start at tdc and continue for about half, or less, then conventional...aprox. 25 degrees....??

Sno2 04:54, 10 April 2007 (UTC)

The Bourke engine cannot achieve a level of boosted pressure in the cylinder before the compression by the piston begins. The reason for this is that the exhaust port is open at the same time as the intake port and vents to the atmosphere. Any pressure introduce by the intake port is vented out the exhaust port. This is not turbocharging or supercharging as no additional fresh intake charge is crammed into the cylinder before the piston begins compressing it. It does provide a means for the intake charge to displace the exhaust but this is no different than any other typical two stroke engine. --DieselDude 22:08, 27 June 2007 (UTC)

Bourke Engine Prototypes

Statements below are inaccurate. There have been over 15 engines have been built, at least 13 by Russell Bourke. Currently there are two (2) water cooled engines available for testing and evaluation. Contact Roger Richard. ALEX… —Preceding unsigned comment added by 68.212.7.32 (talk) 00:59, 23 November 2007 (UTC)

The Bourke engine was built and tested and was in pre-production at one time. I believe that it is a proven engine and not a proposed design.

And yet no performance data has been released to justify the claims made. Greglocock 23:38, 16 March 2007 (UTC)

I seem to remember that just prior to WWII this engine was in pre production (American Motors...??)....am sure there was performance data at that time....and it must have been better then conventional otto engine, or they would not have been prepared to use...is it a proposed engine design if it was in pre-production...??...as I understand it pre-production means it has been tested and approved at one time....am sure not by todays standards as this was done in the 1930's....

However, now that I think about it, cannot remember where I got this info....and cannot find it on the web, or rather a good reference....so have to agree with you, it is in the right category (until I can come up with a reference..<grin>)...

thank you for your comment

Sno2 20:15, 17 March 2007 (UTC)

No, that isn't how Wiki works. Either you provide cites for the claimed performance, or I will edit the claims out. At the time (1930s) performance was no big driver for introducing a new engine, so that proves nothing. There were no standards as such, maybe an SAE power test if you were lucky. Greglocock 13:10, 14 May 2007 (UTC)

Greg...thanks...I understand why this would not be an indication of performance...

Links from other pages...

Needs links from other pages and to other pages. Otto 2 cycle, 4 cycle, turbine...etc.....

Needs links to other pages of different type engines.

Do not know how to do this.

The person that wrote this article claims to have 50 years of experience, and was responsible for Xerox Corporation high growth. He has no experience with engines and has a resume as long as a rap sheet. I guess he really wasn’t employable (not credible). Maybe he really works for oil industry, eye witness account unlikely. http://www.niquette.com/paul/access/prtfolio.html ALEX… —Preceding unsigned comment added by 68.212.7.32 (talk) 02:43, 23 November 2007 (UTC)

Well, he is a real person who answers his emails, not an effectively anonymous contributor to wiki who seems to specialise in randomly inserting paragraphs in other people's comments. WHEN somebody tests one of the 15 Bourke engines and publishes the results then that may confirm the hype. So far all we've got is one test that shows the efficiency is nothing specal. Greglocock (talk) 02:58, 23 November 2007 (UTC)

Note:Actually the following should be included in a link to section. --DieselDude 23:07, 25 June 2007 (UTC)

We should include a link to this eye witness account of how the Bourke engines were tested by Russel Bourke and the people who continued his work using his original engines eye_witness_account --DieselDude 23:07, 25 June 2007 (UTC)

I am 99% sure that it is a work of fiction, or heavily embellished fact. If you put this into the article then please confirm that it is accurate beforehand, I will revert it if you cannot provide this evidence. Greglocock 23:37, 25 June 2007 (UTC)

What leads you to believe that it is not accurate or is embellished? I will remove it for the time being. It has been published although I admit that doesn't make it true.--DieselDude 23:57, 25 June 2007 (UTC)

Just about everything. i've emailed the author. Greglocock 01:31, 26 June 2007 (UTC)

Well, he's sent me a rather aggressive response saying that the account is true. The good news is that the link can go back in. The bad news is that the efficiency he observed is well below that claimed by the enthusiasts, and is in line with normal engineering expectations. I shall adjust the article accordingly. Greglocock 23:38, 26 June 2007 (UTC)

I figured this would be the case. --DieselDude 20:11, 27 June 2007 (UTC)

Diesel...that link to the niquette page has been one of the external links on the bourke page ever since I have seen the page...(over six months ago)....it is the last link "bourke engine"

I have a problem with the testing shown on that page...not that I do not believe it...the author sounds like the engine was sprewing exaust and was running very roughly...this does not agree with the videos of running engines...sounds like it was not balanced....really all the whole article shows is that they were incorrectly measuring the efficiency....does not really say anything about the bourke engine......sno

The way an engine sounds through a video doesn't do justice to the way it sounds in real life. I don't know exactly what video you are referring to but I assume the engine was not under load. An engine under load is a lot louder. This is because more fuel must be burned to do work which leaves a higher residual pressure in the cylinder at the end of the stroke when exhaust is vented. This article is important because it shows that people that worked with Bourke using Bourke's engines they duplicated Bourke's results using a flawed method. This doesn't prove that Bourke used this same flawed test but it does implicate that he did. This is because to get consistent results and measure progress you need to test things the same way each time. Since these people worked with Bourke and knew how he did things they most likely would have done it the exact same way. Their methods were scientific, however their test was flawed. This is probably the origin of all the hype about the Bourke engine.--DieselDude 20:11, 27 June 2007 (UTC)

Introduction

Added introduction to simplified explanation so it could be peer reviewed.Sno2 00:24, 26 May 2007 (UTC)

Efficiency question engineering analysis

I question some of the things in the engineering critique concerning efficiency....believe you are insinuating that the losses are bigger then they actually are...

looking at the thermal efficiency only...

Assume both the bourke and conventional burn the same amount of fuel and the temperatures are the same to begin with, say 2000 degrees.

Assume thermal loss through the cylinder walls are the same.

Both engines running under the same load.

Measured: Bourke exaust temperature around 200 degrees Conventional around 800 degrees

2000 - 200 = 1800 amount of fuel energy equal to 1800 degrees is used, either in load or in internal losses.

2000 - 800 = 1200 amount of fuel energy equal to 1200 degrees is used, either in load or in internal losses.

The difference is about 30 percent.

I do not think the losses you refer to your engineering analysis would lower the final efficiency of the Bourke by more then 5 percent....in fact think it would be probably be around 1 or 2 percent.

With 5 percent still gives 25 percent advantage to bourke

Note: Am giving all the advantage to the conventional...Bourke temperature initially hotter for same amount of fuel...average temperature of cylinder lower in bourke then conventional, less thermal loss through walls.

Does this make sense...and if not why not...??Sno2 21:07, 28 May 2007 (UTC)

sno —The preceding unsigned comment was added by Sno2 (talk • contribs) 22:52, 9 January 2007 (UTC).

How about you stop pulling numbers out of mid-air? The estimation of the efficiency of an engine is quite difficult, I see no sign that you are actually trying to use equations. The Bourke engine is a two stroke engine. The efficiency problems of 2 stroke engines, specifically to do with scavenging are well known. In fact the design of a 2 stroke is largely concerned with scavenging. Your argument about temperatures means nothing if some of the charge escapes with the previous exhaust, (ie a high scavenging ratio is used), whereas if a low scavenging ratio is used the torque developed will drop. Roughly speaking a crossflow scavenged two stroke will dump unburnt HC out of the exhaust if the scavenging ratio is greater than 0.4. Therefore if we believe the test results given, a low scavenging ratio was used, so the maximum torque developed per litre is less than 80% of a normal 4 stroke. Therefore the claims about high power to weight ratio start to look rather suspect. In fact the presence of 60% exhaust in the charge will reduce the burn temperature, and NOx formation, so the thermodynamic efficiency will drop, but at least the NOx formation will be less. On the other hand if the scavenging ratio is 1, as it appears to be from the drawing, then a fair amount of unburnt HC will be exhausted, and the torque will increase. The high combustion temperature will increase the efficincy, although it is unlikely to compensate for the unburnt HCs,and will create NOx. This still leaves the problem that if there is excess air then the burn rate will be slow compared with a conventional mixture, and therefore the claims of high efficiency due to consatnt volume burn look very dodgy. Now, this is all available in the obvious reference J.B. Heywood, "Internal Combustion Engine Fundamentals" so why not save me some time and go and read it. Your misunderstanding of engine balance on my talk page is remarkable for anyone who claims to know anything about engines. Greglocock 00:38, 29 May 2007 (UTC)

If your theory on balance, whatever it may be, that I do not understand, is true....then why is there no evident balance problems on the videos of the running bourke...??...as i remember it experiment trumps theory every time....which means you must be missing something.....I do not have any reference books on thermodynamics any more....lost all my books years ago...will try to get to the library tomorrow and see if I can find the one you reference....and see if I can refresh my memories.....thanks for your reply...Sno2 01:33, 29 May 2007 (UTC)

experiment trumps theory every time = glad to hear that. I have 25 years of experience working on engines and vibration and dynamics. You have what? Greglocock 01:41, 29 May 2007 (UTC)

I have none...however I am beginning to think that I may have more remembered knowledge of thermodynamics....am trying to think of what you may have been missing thinking that there will be an imbalance...maybe you are ignoring the fact the piston slows down relatively slowly because of the action of the yoke...??....the piston in a normal engine comes to a complete stop very quickly....inertia would cause jerkiness in a normal engine.....not sure what difference these two effects would be, but am thinking that absorbing inertia slowly would mute any imbalances.....still not sure what imbalances you are talking about.....Sno2 01:52, 29 May 2007 (UTC)

These claims of efficiency seem fishy to me. It is claimed that the bourke engine uses detonation combustion. This has been shown in experiments to drop the power output of internal combustion engines. http://naca.central.cranfield.ac.uk/reports/1939/naca-tm-911.pdf from scanned page 18 (page 19 in pdf) "Since the total residual charge is ready to ignite by the time the first ignition centers occur, the ignition spreads uncommonly fast, creating a zone of high pressure which move towards the spark plug and even up to the point where combustion had been delayed as a result of cooling. As such a pressure disturbance is reinforced in its during its advance, it might be that this causes the knocking noises on arrival at a rigid wall; similarly as the present measurements indicate it for the detonation wave. This wave also dies out at the combustion chamber walls after repeated reflection. Then the power decrease is the result of the increased heat transfer on the wall, caused by the motion of the gas mass, the temporarily increased pressure at the reflection of the gas vibrations, and the turbulence connected with in." (note: this quote is not from copyrighted material). As all of this takes place near top dead center it will happen the same way in a bourke engine except that the effects will be more so because the bourke engine hold the piston at TDC longer. This will explain the Bourke engines low exhaust temperatures.DieselDude 00:05, 9 June 2007 (UTC)

The theory you present may be correct, guess the only way to find out is when or if they release the measurements on the engines they are testing....I wonder if the piston head shape has anything to do with it...do not understand how they work...thought were like that to seperate input and exaust...wonder if it also controls the detonation wave... here is link to pic of headsSno2 08:06, 10 June 2007 (UTC)

A standard piston engine with a very long connecting rod would almost have the exact sinusoidal piston motion of a Bourke engine. Many claims are made that this sinusoidal motion is what makes the Bourke engine so unique and efficient however these are not realized on an engine with a very long connecting rod. The added weight of a long connecting rod would not account for difference of the claimed bourke performance and the performance seen by the standard piston engine.DieselDude 01:19, 6 July 2007 (UTC)

Engineering removal

Removed reference to bearing problems...no reference to fluid bearing problems available on internet...references found to problems with roller bearings....roller bearings do not have the force handling capability of fluid bearings, see fluid bearing reference in simplified expanation. As designed uses tilting pad fluid bearing.

Revetec

Similar to bourke...opposing pistons...triangle cam..??..no piston slap..complete burn..??..the only claims seem to be low weight....high torque...high efficiency..one of videos here shows torque curve in comparison to conventional.... Sno2 21:42, 26 June 2007 (UTC)

see Revetec Greglocock 01:08, 27 June 2007 (UTC)

If you want to see an engine that puts the Bourke engine to shame, look at the Dynacam engine. You have to use the internet archive because they were taken over by a rival who almost wipe the internet clean of references to its existence. This engine unlike the Bourke, was perfectly balanced. Its design also allowed the piston travel profile to be custom tailored to the combustion process so you could make it sinusoidal or have a different compression or expansion stroke profile. Dyna Cam Engine --DieselDude 15:30, 27 June 2007 (UTC)

Efficiency calculations

Carnot Cycle Ideal Heat Engine Efficiency E = 1 – (T1 – T2) / T1 E = 1 – (2173 – 373 (100 C) / 2173 (1800 C) E = 83 % Idea Efficiency) Actual Measured - ¼ lb/hp hr = 62% (Refer to DOE Paper HCCI) ALEX... —Preceding unsigned comment added by 68.212.7.32 (talk) 23:51, 22 November 2007 (UTC)

For 1 hp burning 1 lb/h of standard gasoline.

calorific value 4.27E+07 J/kg 1 lb/h = 0.454 kg/h fuel energy in per hour= 1.94E+07 J/h Therefore power in= 5385 W

power out =1 hp= 745.7 W efficiency=power out/power in= 13.85% Greglocock 08:36, 27 June 2007 (UTC)

reorganize

Statements below are inaccurate. The detail information on the Bourke Engine operation is CONFIDENTAL and unavailable to the public. Watch the video(s) at http://bourkeengine.net/videoclips.htm. (Probably by ALEX)

If the information is confidential then by definition we can't see it and by definition we can't give a reference to it so by definition it can't go into the article. Please add your comments below preceeding comments, not above them.Greglocock (talk) 10:40, 26 November 2007 (UTC)

I'd like to move all the claimed design features out of the explanation/operation section into the design feature section, and then replace the very confused and unfocussed operation section with the following

(0)Starting from BDC the intake port is covered, so a partial vacuum is created in the compression (lower) chamber. As the piston approaches TDC the intake port is opened, so air is drawn into the compression chamber from the intake duct. This air transfer is irreversible because it involves pumping losses as the air is moved, and the cool incoming air is warmed by the cylinder walls and mixing with any residual warm air from the preceeding cycle.

(1) TDC, with a full charge of air in the compression chamber.

(2) The piston moves down, so the skirt closes both the intake and the transfer port. The air is then compressed by the piston, its temperature and pressure rising roughly in an adiabatic compression. In teh early stages of compression it absorbs heat from the cylinder walls, increasing the work required to compress it. In the later stages of compression it warms the cylinder, resulting in a loss of internal energy. This is inevitable according to 2LOT.

(3) The port in the piston uncovers the transfer port, so the air expands out of the compression chamber, in an irreversible expansion into the combustion chamber. As it does so fuel is injected, the temperature and the pressure drop. The new mixture helps to blow the exhaust out of the exhaust port, as in a traditional cross-scavenged two stroke engine. Inevitably some mixing of the incoming mixture and the exhaust takes place. If the scavenge ratio exceeds 40% some fresh mixture is discharged unburnt out of the exhaust port. The residual exhaust in the chamber, and the walls of the chamber, heat the incoming mixture.

(4) BDC

(5) As the piston moves up the piston ring closes the transfer port in the combustion chamber, and the piston moves up the bore, and compresses the mixture. As in (2) the heat transfer to and from the mixture increases the work required to compress the mixture, in a non-recoverable fashion.

(6) TDC - the mixture is fully compressed, and is now ignited, either by self ignition or by the spark plug.

(7) The rising pressure due to the combustion forces the piston back down the bore. Since the burning/burnt mixture is hot it heats the cylinder walls.

(8) The piston ring uncovers the transfer port and the exhaust port (as in 3), and the exhaust flows out of the exhaust port, pushed out partly by the incoming charge.

Greglocock 00:00, 28 June 2007 (UTC)

I agree that this needs to be done. But I would make the following changes.

(0)Starting from BDC the intake port is covered. As the piston travels toward TDC energy is used to create a partial vacuum in the compression (lower) chamber. As the piston approaches TDC the intake port is opened and air is drawn into the compression chamber from the intake duct. The energy used to create the vacuum cannot be recovered as the air transfer is an irreversible process.

(1) TDC, with a full charge of air in the compression chamber, the cool air is warmed by the cylinder walls and piston.

(2) The piston moves down, so the skirt closes the intake in the beginning of the down stroke. The air is then compressed by the piston, its temperature and pressure rising roughly in an adiabatic compression. In the early stages of compression it absorbs heat from the cylinder walls. In the later stages of compression it warms the cylinder, resulting in a loss of internal energy (This is inevitable according to second law of thermal dynamics regarding energy transfers). Some of this heat is also lost to the cooling system. Given the extended dwell time around BDC this heat loss to the walls is greater than a more conventional two stroke.

(3) Approaching BDC the piston uncovers the transfer port and opens the exhaust port of the combustion chamber. Energy stored in the compressed air in the compression chamber is used to help blow the exhaust out of the exhaust port. As it does so the compressed air expands and cools some and fuel is injected and mixed with the incoming charge. As in a traditional cross-scavenged two stroke engine, inevitably some mixing of the incoming mixture and the exhaust takes place. If the scavenge ratio exceeds 40% some fresh mixture is discharged unburnt out of the exhaust port.

(4) At BDC the residual exhaust in the chamber and the walls of the chamber heat the incoming mixture.

(5) As the piston moves up the piston ring closes the transfer port in the combustion chamber and the exhaust port. As the piston moves up the bore it re-compresses the mixture causing it to heat up and transfer heat back into the walls. As in (2) the heat transfer to and from the mixture increases the internal energy loss from the mixture. Also as in (2) some of this heat lost to the walls is lost to the cooling system. Since the Bourke engine has extended dwell time near TDC the air charge is held in a compressed heated state, exacerbating the heat loss to the walls.

(6) TDC - the mixture is fully compressed, and is now ignited, either by self ignition or by the spark plug. If the mixture detonates it will cause shock waves to bounce around the combustion chamber. Each time these shock waves bounce off a wall or the piston the compressed charge forming the shock wave transfers heat to the piston or combustion chamber wall losing energy that otherwise could be extracted in the power stroke.

(7) The rising pressure due to the combustion forces the piston back down the bore. Since the burning/burnt mixture is hot it heats the cylinder walls. The extended dwell time around TDC ensures almost complete combustion of all the fuel. However as in (5), the extended dwell time also increases the amount of heat transfered to the walls which is later lost to the cooling system.

(8) The piston ring uncovers the transfer port and the exhaust port (as in 3), and the exhaust flows out of the exhaust port, pushed out partly by the incoming charge.

--DieselDude 01:33, 28 June 2007 (UTC)

Nice. Done. Can someone archive the above section to reduce the size of this page? Greglocock 02:29, 28 June 2007 (UTC)

I think we should leave it long because we are always going to have people coming here and arguing that the Bourke engine is the greatest thing since sliced bread. --DieselDude 15:05, 28 June 2007 (UTC)