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New form of Gas ignition

Old 10-31-2010, 08:40 PM
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captinjohn
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Default New form of Gas ignition

If this new gas ignition that Enya has developed works as planned....you will not need any CD unit, Switch ,extra battery, timing pick-upfor ignition and the dreaded glitches cause by CD system will be gone forever. Here is a link to a similar system....more on the Enya layer. Capt,n<hr />http://www.smartplugs.com/engines/2stroke/

http://enya-engine.com/180XGS_E.html

This engine will have zero sparking noise! A real big advantage!!!!!
Old 10-31-2010, 08:48 PM
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Default RE: New form of Gas ignition

Interesting...
Old 10-31-2010, 09:32 PM
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captinjohn
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Default RE: New form of Gas ignition

I forgot to say...this new Gas Enya RC engine is going to be introduced in november some time. I cannot wait to read a review on them. Capt,n
Old 10-31-2010, 09:38 PM
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the Wasp
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Default RE: New form of Gas ignition

he inside of the plug here ,,,

http://www.smartplugs.com/smartplug/animatedplug.htm
Old 10-31-2010, 09:40 PM
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Default RE: New form of Gas ignition

Looking forward to hearing more about this item. looks like a second combustion chamber with a glow elementis usedto ignite the main cylinder.
Old 10-31-2010, 10:17 PM
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Default RE: New form of Gas ignition

The "Smart Plugs" have been around for a long time, but they never seem to be able to get them into production and available. Hopefully this time they will. We'll see...

AV8TOR
Old 10-31-2010, 10:31 PM
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Default RE: New form of Gas ignition

with the price of some Glow Plugs I'm wondering what the Smart Plug will cost

Jim
Old 10-31-2010, 10:52 PM
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Default RE: New form of Gas ignition

I remember this idea from the '60s. Hot Rod magazine ran an article on something like this. The way I remember it they used a spark plug in a small chamber that screwed into the spark plug hole. they said industrial engines were using it.
Old 10-31-2010, 11:03 PM
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Default RE: New form of Gas ignition

Smartplugs, old idea that doesnt work in reality. The idea has been around for 60 years and tried by almost every engine company out there. Much like a glow plug, the ignition event is a time/temperature/pressure controlled event. Unfortunately gasoline does not behave the way alcohol does relative to temperature/pressure, and is a mixture of chemicals rather than one. So not only does comression ratio and temperatures become much more critical, now add a fuel that is always changing. The engine world has a hard enough time calibrating engines for todays gasolines using spark, this idea has no chance. Unfortunately something else to file under " too good and simple to be true". Enya might get it to function in a tiny engine, which is much more tolerant of erratic combustion.
Old 11-01-2010, 09:16 AM
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captinjohn
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Default RE: New form of Gas ignition


ORIGINAL: makoman1860

Smartplugs, old idea that doesnt work in reality. The idea has been around for 60 years and tried by almost every engine company out there. Much like a glow plug, the ignition event is a time/temperature/pressure controlled event. Unfortunately gasoline does not behave the way alcohol does relative to temperature/pressure, and is a mixture of chemicals rather than one. So not only does comression ratio and temperatures become much more critical, now add a fuel that is always changing. The engine world has a hard enough time calibrating engines for todays gasolines using spark, this idea has no chance. Unfortunately something else to file under " too good and simple to be true". Enya might get it to function in a tiny engine, which is much more tolerant of erratic combustion.
Well sir you are kinda a KILL-JOY. Have you tried one yourself.? Don,t you think maybe Enya may have come up with somthing that works . The example of the Smart plug was just that ...a example. I never said Enya used a smart plug. I have known about the smart plug for a few years....by reading. Well I hope you did not kill everyones thought that Enya may have a good working engine. Sheeeeish!
Old 11-01-2010, 10:14 AM
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Default RE: New form of Gas ignition

Tried a version of these years ago with mixed results.
Old 11-01-2010, 10:38 AM
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captinjohn
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Default RE: New form of Gas ignition


ORIGINAL: WRK

Tried a version of these years ago with mixed results.
Was the trial in a RC engine? What size & compression ratio...ect? What was the good or bad results? Maybe others on line clould help with a fuel mix that may work better. It is good to share ideas...that isone way things get fine tunned. Best regards Capt,n<hr />Just a update...some postings are rather long...you may want to go to last post!
Old 11-01-2010, 01:49 PM
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pe reivers
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Default RE: New form of Gas ignition

Hmm.. Enya did not reveal what system they realy use. Battery supported plugs maybe? I ran my engines using a mix of naphta and ATF oil to get all traces of methanol and nitro out them at the end of the day in order to prevent corrosion. Maybe Enya has perfected something like that.
Old 11-01-2010, 11:55 PM
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Default RE: New form of Gas ignition


ORIGINAL: captinjohn


ORIGINAL: makoman1860

Smartplugs, old idea that doesnt work in reality. The idea has been around for 60 years and tried by almost every engine company out there. Much like a glow plug, the ignition event is a time/temperature/pressure controlled event. Unfortunately gasoline does not behave the way alcohol does relative to temperature/pressure, and is a mixture of chemicals rather than one. So not only does comression ratio and temperatures become much more critical, now add a fuel that is always changing. The engine world has a hard enough time calibrating engines for todays gasolines using spark, this idea has no chance. Unfortunately something else to file under '' too good and simple to be true''. Enya might get it to function in a tiny engine, which is much more tolerant of erratic combustion.
Well sir you are kinda a KILL-JOY. Have you tried one yourself.? Don,t you think maybe Enya may have come up with somthing that works . The example of the Smart plug was just that ...a example. I never said Enya used a smart plug. I have known about the smart plug for a few years....by reading. Well I hope you did not kill everyones thought that Enya may have a good working engine. Sheeeeish![img][/img]
KillJoy? Well I hope not, more of a realist. Like I said, they probably got something to "work", but I can be put on record here doubting its performance. You cant run an engine on gasoline with optimum compression pressures and run autoigintion. Its either going to be so finicky of fuel type, mixture, temperature and propping that few get them to run, or they will have to de-tune the engine to the point that the skin on the pudding is fairly safe. Maybe I will be proven wrong...never know.
Old 11-02-2010, 05:00 PM
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Default RE: New form of Gas ignition

A little something to pass the time. It impacts ignitions and spark plugs tremendously.


DETO!
By Kevin Cameron The Cellar Dweller

I first encountered detonation back in 1966, and I didn't know what it was. Fortunately for me, it was a light case, and the only symptoms were small holes being eaten into the edges of a motorcycle cylinder head's squish band.

Later, pushing to higher compression, I would generate my share of pistons that were detonated away until their rings hung out into empty space. I would learn to look out for the tiny, ash gray flake of quenched aluminum on a spark plug, or in water-cooled engines, for the sudden and otherwise unexplained rise in engine temperature. And I would still be curious about those dusty holes, eroded into cylinder heads.

Books will tell you what Harry Ricardo learned back in 1918; that detonation is not the same as preignition. Preignition is lighting of the charge before the spark , by some hot object in the combustion chamber usually the overheated center wire of a spark plug whose heat range was too hot for the application. Preignition soon provokes detonation, so the confusion is understandable.

Detonation, by contrast, is self ignition of some of the last parts of the charge to burn the so-called "end gas" out at the edges of the combustion chamber after the spark has already ignited and mostly burned the charge. This self igniting endgas does not then burn normally, as a flame front spread by turbulence at the usual speed of a few tens of feet per second. This gas burns at the local speed of sound, which is very high because the temperature is high. This form of combustion, called detonation, forms a shock front, a sudden jump in pressure that propagates at thousands of feet per second.

When it hits parts, it hits hard. If we hear it al all, it is as a high, dry, irregular clicking, not unlike the reverberating sound of rocks struck under water. Detonation's pressure front can damage bearings by its hammering shock, but the real problem is what it does to an engine's natural, internal insulation.

In any situation in which gases move next to solid surfaces, there is a layer of significant thickness that remains largely stagnant because it is attached to the surface. In internal combustion engines, this boundary layer quite effectively shields the engine's metal internal surfaces from direct contact with combustion gas, keeping them cooler than they would otherwise be.

When detonation begins even light deto this boundary layer is scoured off by the impacting shock waves, and heat transfer from hot gas to cool metal accelerates. In only a very few detonating cycles, piston temperatures rise dramatically, and the rest of the parts exposed to combustion gas aren't far behind.

What is strange to many people is that as this happens, exhaust gas temperature falls. This seems odd because people associate detonation with heat, and heat with failure. But the fact is that as you jet an engine down, its exhaust temperatures peak, not when the mixture becomes lean (that is, too little fuel to react with all the oxygen in the air charge), but when the mixture is chemically perfect. Exhaust gas temperature falls when detonation begins because the engine's internal insulation is destroyed; that being so, some heat that would otherwise go out the exhaust is now being diverted into the piston, head, and cylinder walls. Because those parts are getting hotter, the exhaust gas becomes colder.

Those of us who began racing before water cooling arrived tend to think that engines get hotter the more we jet them down. With air cooling, this seems to be true, but isn't. The engine runs cool when it's rich because the extra fuel reduces peak flame temperature, and as we jet down towards chemically correct mixture, the engine runs hotter and hotter. Often, in a modified engine with high compression, this detonation begins even before we reach correct mixture and peak flame temperature. Then the engine really heats up. This leaves us with the idea that leaning down the mixture raises engine temperature, in a straightline relationship.

Now we know, from our experiences with water-cooled engines, that power, engine temperature, and exhaust gas temperature all rise as we jet down until we go beyond chemically correct mixture. When we do, power, engine temperature, and exhaust gas temperature all begin to fall again. We couldn't see this before, with air-cooling, because the power we were making was overwhelming the engines the engine's cooling ability. But it makes perfect sense because heat release in combustion depends upon finding enough oxygen so that each and every hydrogen and carbon in the fuel is completely reacted to form water and carbon dioxide. Any fuel left over is potential chemical energy unreleased which is why running lean makes less power. On lay well cooled engine that is not detonating, you can jet down until it starts to slow down.

Now back to detonation. The above explanation is the common one, but it leaves important questions unanswered. For example, why does detonating combustion travel at the local speed of sound, and not at normal burning speed? Why does the endgas auto ignite, rather than simply wait there like a stand of trees in the path of a forest fire? Understanding how this comes about helps to understand how the variables that affect detonation generate their effects and it helps to fend off the phenomenon that sets the upper limits on performance.

There are two basic forms of combustion, deflagration and detonation. In deflagration, the propagation of combustion is carried out by simple convection; the hot combustion gas heats what is ahead of it, raising its temperature to the ignition point. Because this process of heating what lies ahead takes time, it is relatively slow. The burning of a quiescent gasoline air vapor is in fact slow only a foot or so per second. Combustion in an engine cylinder is much faster than this because of turbulence, which so wrinkles the flame front that its area becomes hugely enlarged. This area, multiplied times the slow quiescent combustion speed, computes out to a very large volume combustion rate.

Detonation is a different animal, and not all gaseous mixtures will support detonation. It is a form of combustion in which the unburned material is heated to ignition at least partly by shock compression, as the detonation wave moves a the local speed of sound through the medium. This has to happen very quickly, so fuels with simple molecules or those with low stability lend themselves to this form of combustion. Now how does the endgas ignite by itself? It does so when its temperature is raised by any combination of effects to some critical value in the range of 900-1000 degrees F.

In a running engine, air is drawn in at some ambient temperature, and this air then begins to pick up heat from the hot internal engine surfaces it contacts. Finally it enters the actual cylinder, where is it heated by even hotter surfaces. Trapped there, it is heated again by the process of compression.

In this heating process, some little discussed chemical reactions begin to occur in the fuel. Called preflame reactions, these take the form of slow, partial breakdown of the least durable types of fuel molecule. Fuel hydrocarbons have three basic forms; straight carbon chains, branched chains, and ring structures. Temperature is a measure of average molecular activity, but there are always some gas molecules moving significantly faster than the others. These faster moving molecules hit and break some of the less durable fuel molecules, dislodging some of their more weakly bonded hydrogen atoms. This released hydrogen is very reactive (normally hydrogenous travel in bonded pairs, but his is atomic hydrogen) and instantly pairs with an oxygen from the air to form what is called a radical, a chemical fragment that is highly reactive because if contains and unpaired electron. Its attraction for the missing electron is so great that it can snap one out of other chemical species it happens to collide with, thereby breaking it down as well.

At some point in the compression stroke, the spark ignites the mixture and combustion begins. The burned gases, being very hot, expand against the still unburned charge, compressing it outward into the squish band. This compression rapidly heats the unburned charge even more, accelerating the preflame reactions in it. As a rule of thumb, the rate of chemical reaction doubles every seventeen degrees F. All this while, the population of reactive molecular fragments radicals is increasing in the unburned endgas. If this process of heating takes long enough, and reaches a temperature high enough, this population of radicals becomes great enough that its own reaction rate one radical creating more and more through further reactions accelerates into outright combustion. This is autoignition.

Now why does this heated, chemically changed endgas detonate instead of simply burning? The fuel in the endgas is no longer ordinary gasoline. The preflame reaction that have taken place in it have changed it into a violent explosive much like a mixture of hydrogen and air, or acetylene and oxygen. It is in a hair-trigger state, being filled with reactive fragments from preflame reactions. When it autoignites spontaneously, combustion accelerates almost instantly because the material is so easily ignited now. The combustion front accelerates to the local speed of sound, igniting the material it passes through simply by suddenly raising its temperature, through the shock wave it has now become.

STOPPING THE SHOW

Anything that contributes to lowering the temperature that the endgas reaches will make detonation less likely. Anything that slows the process of conversion from normal gasoline into a sensitive explosive, will make detonation less likely. Anything that speeds up combustion, so that is it completed before the conditions needed for detonation can develop fully, will make deto less likely.

Therefore the following will work;

(1) Lower intake temperature

(2) Lower throttle position, lower volumetric efficiency, or reduced turbo boost the less mixture that enters the cylinder, the less it is heated by compression.

(3) Lower intake pipe, crankcase, and/or cylinder, piston, or head temperatures. This year's Yamaha 250cc road race engine, for instance, has a copper cylinder head insert to conduct combustion heat away faster, resulting in a lower combustion chamber surface temperature.

(4) Lower compression ratio. The less you squeeze it, the less it is heated.

(5) A more breakdown resistant fuel, such as toluene or isooctane. If straight chain molecules are not present, the fuel will not be broken down so rapidly by preflame reactions.

(6) A negative catalyst something that will either pin down active radicals or convert them into something harmless. Tetraethyl lead, MMT, or other antiknock compounds are the medicine.

(7) Retarded timing shortens the time during which proknock reactions can take place.

(8) Incylinder turbulence or anything else that will speed up combustion (faster burning fuel such as benzene). This works by completing combustion before the time bomb of preflame reactions cooks long enough to cause autoignition.

(9) Higher engine rpm This simply shortens the time during which the mixture is held at high temp. In Honda experiments in the 1960's, they found that an engine's octane requirements began to decrease steadily over 12,000 rpm, and were under 60 octane up near 20,000. In a more accessible example, note that engines knock when they are "lugged" run at low rpm, wide open throttle and stop knocking promptly when you shift down a gear and let the engine rev up more. This stops deto by not allowing enough time for the reactions that cause it.

(10) Redesigning troublesome exhaust pipes. Some pipes give great numbers on the dyno, but can't be used because they cause seizures. They either simply overcharge the engine in some narrow rpm band (pushing it into detonation just as too much turbo boost would do), or back pump mixture from the header pipe that has picked up too much heat (this is why nobody heat wraps header pipes anymore).

(11) Avoiding excessive backpressure. Exhaust pipes always create back pressure, but the more there is, the higher the fraction of hot exhaust gas that will be unable to leave the cylinder during exhaust. Its heat, added to the fresh charge that next enters the cylinder, may push the engine over the line into detonation. Sometimes a one or two millimeter reduction in tailpipe ID will get you a couple of extra horsepower, but it may also push enough extra heat into the charge to make the engine detonate after a few seconds.

The number of ways of playing footsie with detonation is endless, but nothing works every time. This guarantees that we will never be bored, and will never run out of seized pistons.
Old 11-02-2010, 05:50 PM
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Default RE: New form of Gas ignition

Interesting, that article makes no mention of squish.
Old 11-02-2010, 06:03 PM
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Default RE: New form of Gas ignition

No, it does not. I never said it was all encompassing;0 For all intents and purposes it's only for a reasonable entry level recognition reference. The amount of information, and areas that impact detonation, cover a large spectrum. The last sentence in the article somewhat alludes to that.

On a more serious note, I don't try to turn this forum into a mechanical or propulsion engineering class. If I was to do so I would be looking for a big pay raise and tenure at a college somewhere. I'm not that smart, or good enough to perform that undertaking. If people want more information, they can do searches, buy books, and perform their own research. There are so many different levels of comprehension in these forums that an attempt to teach everyone is impossible. You need to start with some level of playing field, and choosing the lowest level would be a daunting, thankless, and impossible task.
Old 11-02-2010, 06:08 PM
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Default RE: New form of Gas ignition

now i know what caused that ugly knocking noise on my 1.60fx... all i know was that ritchening the low end took care of it
Old 11-02-2010, 06:26 PM
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Default RE: New form of Gas ignition

Interesting article. Answered a few questions Iv'd had for a while.
Tks for posting.
Old 11-02-2010, 07:33 PM
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Default RE: New form of Gas ignition


ORIGINAL: MetallicaJunkie

now i know what caused that ugly knocking noise on my 1.60fx... all i know was that ritchening the low end took care of it
Same here, but I slightly raised the back pressure of the muffler. By doing so it improved the tank pressure at lower throttle settings making the mixture richer and took away the midrange knock.

Thanks for the great read Pat.
Old 11-02-2010, 07:54 PM
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Default RE: New form of Gas ignition

My friend had a book on "Super Tunning" and it was the most in-depth book with every aspect possible. I wish my eyes was better....I would borrow it. I think in general short strokesparkengines are less prone to spark nock...or pre-detanation. Capt,n
Old 11-02-2010, 08:36 PM
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Default RE: New form of Gas ignition

Not true. I've been quite involved with severe detonation issues in our small engines for the past couple of months. When the dominoes are lined up correctly, detontion in our engines is a very serious issue. One that occurs on a much higher frequency than many realize.
Old 11-02-2010, 08:50 PM
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TOM, I was refering to spark engines in cars....you did talk about turbos in your last post & a lot of data that refered to all sizes & types of engines. Sorry I read it wrong. Capt,n
Old 11-02-2010, 08:54 PM
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Default RE: New form of Gas ignition

I learned about the dangers of detonation when I was modifying my 01 Mustang and installed a supercharger on it. When running high boost if you get some bad gas sever detonation can destroy an engine in a matter of seconds.
Old 11-02-2010, 09:31 PM
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captinjohn
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Default RE: New form of Gas ignition

I have read that sometimes the compression ratio is lowered quite a bit on some engines. Super chargingcanadd too the compression ...sometimes too much.

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