Gasoline VAPOR?

[Mr Pickles]

Hey everyone my name Adam I'm 43 and I live near Los Angeles. I converted a motorcycle, a carbureted Kawasaki V-Twin 97 Vulcan 800, to run on gasoline vapor a few years back. I had a new motor, Suzuki tl1000 practically brand new, did I intended to swap in so before doing so I decided to attempt gasoline vapor. I simply pipes my cold air through my gas tank agitating the surface of the gasoline and then sucking that air through the mouth of my carb where my air cleaner would have been with a couple of flashback arresters. Initially it had trouble idling but as someone mentioned in an earlier thread if you stayed on the throttle it ran great. A bit lean but no problem to ride. Again an earlier post mentioned the temperature being a factor and I would say absolutely. As you pull the air through the gasoline the gas gets colder and colder making it more and more lean. Also with the addition of a small computer fan forcing cold air in at the very beginning I was able to idle normally. My understanding is that in a modern car the shaft that spins opening and closing exhaust versus intake need to be spaced further apart to prevent pre-ignition as the vapor mixture is very flammable and can be ignited from the exhaust of the previous explosion. However if you were to redesign said shaft then gasoline paper would be very doable in a modern car with some reprogramming of the computer parameters I swap the engines before doing much experimentation but it does work it is not mythical and honestly it blew my mind.

[Mr Pickles]

One other th one last point if I was to do the project today I would definitely attempt to use ultrasonic vaporization to replace the computer fan for idling

[racprops]

I am back:


Vapor build:


First a replay to the bad belief that today’s engines burn all the fuel within the combustion stroke: WRONG!!


In fact a good percentage of the fuel is still burning as the piston passed BDC after the power stroke and is still burning as the piston starts on the upward exhaust stroke and still burning as it passes the exhaust valve and still burning as it passes though the exhaust manifold.

The cooling system is need to handle most of this wasted heat to keep the engine from overheating.


And the catalytic convertor is there to FINISH as much as it can BURNING the remaining unburned fuel which with OUT unburned fuel it will GO COLD. The Cats NEED unburned fuel to heat up and work.


SO the modern car is at best 30% efficient, that is 30% of the gasoline put into it does any real work in pushing the piston down.


OK here is the theory behind this claim.


ONLY vapor burns, but getting gasoline into a vapor sate is not easy, so cars rely on the fuel droplets vaporizing on their own, in carbs some happened as fuel was mixed with air from the carb to the combustion chamber. Some might be happening with Throttle Body Injection as there is some little time for the air and fuel to mix on its way to the combustion chamber.


This no longer happens with port injection and direct injection. But Port injection in the early Tuned Port Injection system did do a funny thing, inject fuel onto the hot intake valve which help vaporize the fuel before the valve opened….


So now we have to now rely on the heat in the combustion chamber to try to convert the fuel to vapor, note there is no real time so only 20 to 30% gets converted.


Also gas burning in an ICE (internal Combustion Engine) needs a lot of lead time so we start this burning up to 40+ degrees BEFORE Top Dead Center, and sadly it keeps burning after the power stroke and as it exits the engine and then in the exhaust manifold and so on. The left over still burning fuel is ALL wasted. Even Exhaust Gas Return does only used very little of this.
This is what the catalytic convertor burns.


Vapor on the other hand burns very fast, and needs no advance start to its burning, so it can be fired AT TDC and then can product full power for the power stroke from TDC to BDC (Bottom dead center) And it can be almost all consumed at that point so there is NO burning fuel exiting the engine.


So this will use a much lesser amount of fuel (perhaps only 30%) to do the same work and none is wasted so the extra 60 to 80% is not needed.


As for the Fuel Vapor thing, I see it as a grass roots deal, working out how to do it and as an add-on device it could be put onto any car, and to help avoid suppression I figured on Public Domain it all over the internet with the plans so almost anyone can make them…with the correct tools.


I also plan on an open letter to all concerned, that with the possibility that oil will run out some day, this would triple the supplies as we would be using 2/3 less, and polluting 2/3 or less, which would make the Internal Combustion Engine very competitive to the Electric Cars.


And as it can be added to any car allowing mass improvement in both MPG and PPM (Pollution Per Mile) as any and every car could be converted to its use.


This could help EVERYONE, not the rich whom can afford these new cars, who hardly need any gas saving cars, it is just an IN thing to do.


Consider how much savings a 75 to 125 MPG car would mean to everyone and how it possibility run super clean and how low the demand FOR Gasoline would become and how many decades even perhaps lifetimes it will take to use up all the oil and a say 30% of the current rate of use.


One of the main concerns has been at the high temps needed to fully vaporize todays gasoline there is a very real problem of vapor so hot it will burn with any air.


My ideas include using the current engine cooling water system to also cool these vapors to a much safer non-auto-flammable temps for safer insertion into engine’s intake, and which in cold weather will make up for the lost heat from a cooler vapor burning engine.


At last I came up with what I believe is an answer to those problems:


Three to four one-way flapper valves to keep outside air from getting in.


Sensors to detect any unwanted BURNING fuel in system and instant shut down.


Low temp startup of system to insure positive only fuel vapor in system before full heat is applied with pressure sensors.


Ceramic (or similar) tiles as insolation.


Possible a second (secondary) feed for added power?



My understanding is once converted to 100% vapor that it is a fact and law of nature stuff will remain in its current state of matter, be it a solid, or liquid, and vapor, that to convert it to another state takes a fair amount of energy to cause such a change of state, thus once in a gas state it will take a lot to convert it back to a liquid.

There are very real risks to do this most ways...the main one is most systems make vapor after an engine is turned off and such vapor under the hood is very dangerous... my system based on a other invention, will produce just the right amount of vapor on demand and will stop within a few seconds when shut off.

[racprops]

Here is a very good and deep article:


Rudolf Diesel invented the compression ignition engine in 1897. Shortly thereafter, advances in the refining industry produced gasoline--but not in its modern form. Back then, gasoline was basically a derivative of kerosene, a waste byproduct of early oil refining. It was considered a nuisance and was disposed of by being dumped onto the ground or into rivers.


An exhaust stove (arrow) pulled heat--but not exhaust gas--from the manifold and fed it to the carburetor.
Soon, however, inventors recognized that gasoline's high energy potential made it an ideal fuel, something that could advance engine development. There was a problem, though: Gasoline does not burn in liquid form. It needs to be atomized, emulsified and vaporized to ignite. This means it must be broken down into small particles, be mixed with air, and undergo a phase change through heat. The carburetor's job is to accomplish the first two steps, while a process called the latent heat of vaporization takes credit for the last step.


Vaporizing the fuel:

Early inventors were puzzled by the characteristics of gasoline; it took some time and innovation for scientists to fully understand its properties. We don't know who first discovered that gasoline's vapors are what burns, not its liquid form. One theory is that the discovery was triggered by lighting strikes after the unwanted fuel was discarded--dumped liquid gasoline leeched into the soil, but its vapors in the air above could still catch fire.


One property of gasoline is that the more heat it is exposed to, the more volatile its vapors become. In order to use gasoline as a fuel for an internal combustion engine, something had to heat it, forcing it into a vapor phase. That something is the carburetor.


Changing gasoline from a liquid to a vapor requires energy. The liquid molecule needs to break its bond and become a vapor in much the same way water evaporates from your skin on a hot day. The water gains the needed energy by taking a tiny amount of heat from your skin; that is what helps keep you cool. The heat does not disappear; rather, it is converted into the vapor molecule's added energy. As the vapor molecule moves away from your body, it takes this energy, called latent heat, with it. When the vapor molecule condenses back into a liquid, it releases latent heat, warming its surroundings.


Gasoline's phase change occurs in the intake manifold and requires the fuel to be fully atomized.


A poor atomization rate will result in only a small percentage turning to a vapor. Therefore, it's critical that the carburetor be efficient at breaking down the liquid gasoline particles and mixing them with air.


Just like water evaporates from skin, gasoline evaporates, changing phase to a gas, while traveling to the cylinder head intake runner. This process requires the addition of heat, and vaporization ends up cooling the intake manifold: The latent heat is transferred to the vaporized fuel and leaves the surrounding area at a lower temperature. The more thorough the rate of vaporization, the greater the amount of work the engine performs for the fuel consumed. If the rate is poor, the amount of potential energy (measured in BTU) obtained during the conversion process is correspondingly low.
Friend and foe

To the engine designer, heating the induction path has both a positive and negative effect.


Heat is necessary for gasoline to vaporize. A general rule that still applies to modern gasoline is that, at a temperature of 60 degrees Fahrenheit, only 50 percent of the liquid gasoline converts to vapor. At near freezing temperatures, that percentage declines to approximately 20 percent. At -45 degrees, there is no chance of vaporization and the gasoline engine will stop running. For the engine to start at this temperature, an external heat source is required.


These temperatures are not the ambient air temperature; rather, what has to be considered is the temperature in the intake manifold where the phase change will occur. Thus, it's possible to run a gasoline engine at -45 degrees or colder when the underhood temperature is above the ambient air temperature.


Due to the poor rate of vaporization of gasoline, carburetors require a device called a choke. The choke enriches the air/fuel ratio so there is a sufficient amount of vaporized fuel to allow the engine to start. Most early engines would crank at a mixture strength of 2:1 (two parts air to one part fuel) and warm up at a rate of 7:1. The mixture would gradually lean out to the desired 14.7:1 ratio, which is the stoichiometric value of gasoline. "Stoichiometric value" describes the exact recipe of air and fuel that will allow for the most complete release of chemical energy from the mass of fuel consumed.

Though heat is a friend to a cold engine, it is a foe once the engine is fully warmed up.


As air is heated, it becomes less dense; because oxygen is required to support combustion, the volumetric efficiency of the engine suffers. For approximately every 10 degrees the air is heated, the engine's power drops by 1 percent.


Additionally, heated air makes an engine more prone to abnormal combustion, better known as detonation. The inverse also applies: On a very cold day, an engine seems more powerful, because the air being ingested is packed with more oxygen molecules.


Thus, auto engineers needed to find a way to heat the incoming air when the engine was cold, to aid start-up and driveability during the intermediate temperature phase, while not limiting volumetric efficiency during normal operation.


Carburetor icing

The problem of carburetor icing has been around as long as the carburetor itself. The vaporization of the fuel removes heat from the intake manifold and carburetor venturi, which can cause ice deposits to occur when moist intake air condenses in the carburetor body or base plate assembly.


This normally happens at ambient temperatures that are above freezing, and can occur even up into the middle 50-degree range. Icing is most common, though, with air around 25 to 45 degrees that has a relative humidity of 80 percent or greater. At lower temperatures and humidity levels, there is not enough water in the air to create an icing problem; at higher ambient temperatures, ice won't form.


Ice deposits can be identified by the region of the carburetor on which they form and ultimately restrict the flow of both the air and mixture. Where the formations occur varies with carburetor design and engine application and use, and the location of the ice determines how the driveability is impacted.


If ice forms on the throttle plates, it will have a significant effect on the air/fuel ratio only at very low throttle openings or when the throttle is closed completely, such as when the engine is required to idle. This type of icing is known as idle icing and is most common in city driving during the engine warm-up period. During idle icing, the throttle plates become covered with ice and choke off the air, causing the engine to stall.


Ice can also form in the venturi of the carburetor during cruise conditions; this is called cruise icing. These deposits tend to cause a power loss during cruise conditions, because the deposits restrict air flow and can restrict the signal to the main metering circuit. The drop in power can become so great that the vehicle may come to a complete halt. This problem is hard to diagnose, because it takes only a few minutes for the ice to melt and the power to return if the engine is shut off, thanks to the heat soak that warms the carburetor when the engine has stalled or has been turned off. Oil companies work hard to develop additives to limit icing, but the laws of Mother Nature still prevail.


Some like it hot
During the early days of the automobile, many different methods of heating the incoming air to aid in fuel vaporization were tried. Detroit's various approaches can be broken down into seven categories:


All of these methods had their benefits and disadvantages. Using the engine coolant as a heating method did not do much to help the fuel vaporize right after startup. It took a few minutes for the coolant to gain any heat from the running engine; even then, the temperature built slowly. The slow rate of heat transfer into the coolant and then into either the carburetor or intake manifold was beneficial during warmup, but not at the initial start of the engine.


Exhaust gas proved to be much more effective; as soon as the engine fired, the exhaust temperature immediately reached a few hundred degrees and could warm the area where vaporization occurs. Placing the intake and exhaust manifolds in close proximity was an inexpensive and simple method to heat the fuel, but severely limited engine performance when the engine was fully warmed.


Packard's "fuelizer" was another solution, one that required a small combustion chamber in the intake manifold to create a flame and heat the charge. Though very effective, the fuelizer faced almost the same ignition temperature quandary that the manifold solution did. Its benefit was the combustion area was very small and could be ignited easier than the cylinder bore. Gasoline was supplied by a bypass pipe from the carburetor and the fuelizer employed its own dedicated spark plug.


Eventually, hot exhaust gas was chosen as the most practical and effective way to aid the vaporization rate. The system evolved into the modern heat riser valve, which directs spent gases from the exhaust manifold through the cylinder head and under the carburetor pad of the intake manifold on the floor of the plenum.


With any type of external heat source, a thermostatic control was needed to monitor the engine temperature and cut off heating when necessary to improve volumetric efficiency and octane tolerance.


The battle to vaporize fuel is still being fought today. Electronic fuel injection is designed to have the nozzle spray against the intake valve. With the valve face exposed to the combustion chamber, it quickly builds temperature and allows the conversion rate to improve greatly on a cold engine, when compared to a carburetor application.


But one of the greatest uses of fuel vaporization has been forgotten by most Americans. During World War II and the battle between Rommel and Patton in the African theater of operations, fuel was in very short supply, especially for the Germans.


Patton recognized this and some historians argue that a young G.I. named Pogue came up with an idea of placing an electric heating coil in the venturi of the carburetor used in the tank engine. Though it limited volumetric efficiency, the heated air greatly improved fuel efficiency. Patton then formulated a battle plan that got the German commander to chase him around the desert until Rommel ran out of fuel. Still mobile, thanks to Pogue's efficient engine adaptations, Patton then went in for the kill.


It may be that recognizing the latent heat of vaporization helped America win the war.


A personal note is how may cars now have a cooler plastic intake manifold, where this make more HP I suspect it also lowers possible good MPG…it is an interesting point that Power can help MPG but more power also lower MPG…I wonder at what point these two thing pass each another?

[Hersbird]

So why doesn't propane or LPG work?

[racprops]

They do BUT lack the energy (power) of gasoline or BTUs.

As in a home power Tri-Fuel Portable Generator power ratings on these three fuels:

13500/12500/10000 Peak | 10500/9500/8500 Rated Watts (Gas/LPG/NG)

Note gasoline makes the most power, and it goes down hill from there.

You get MORE Bang for your buck.

Gasoline is just about the most powerful fuel we have.

Rich

[Ecky]

What I'm curious about is, why propane-powered engines produce approximately the same power produced relative to the BTUs of the fuel put in, as gasoline, even though the propane is already fully vaporized. Gasoline has ~31% more BTUs per gallon. If I've read your hypothesis correctly, and only ~30% of gasoline actually vaporizes and burns when it should, wouldn't we expect propane to make more power? Since all of it can burn immediately?

Propane BTUs per gallon: 95,000
Gasoline BTUs per gallon: 125,000
30% of Gasoline BTUs: 37,500

Going by this, we'd expect 3x better fuel economy and 3x more power out of an equal volume of propane.

Edit: A quick search reveals this cited chart on ResearchGate:

https://www.researchgate.net/figure/...ig18_263874565

[racprops]

My best guess is the compression ratios are not best for anything other than gasoline, also unless retuned for the vapor the firing timing is also wrong.

Gasoline timing can be from 20 to 40 Degrees Before Top Dead Center, that is because gasoline does not explode, it burns and in the spit seconds of a compression and power stroke SLOWLY...so they start it burning BEFORE full compression, I wonder if this pre-build up of pressure doesn't hurt MPG some.

Part of this pre-burn is also to raise the heat to help more of the liquid droplets to vaporize.

My reading of the claimed use of 100% pure gasoline vapor will need zero degrees timing as the vapor nearly does explode and burns so fast that it is spent closer to the best timing of the power stroke:

As in 5 Degrees to 125/150 Degrees THIS is the power stroke, when the most work is done.

So no preburning of the fuel.

If what I have read is correct.

This is a problem with many newer cars, my 93 van I just disconnect it timing control plug and it is running what timing the distributor is set for.

Computer controlled cars will need a overriding program, best would be two settings one for gasoline and one for vapor.

So adding any propane or LPG without reprogramming and it may very well bolix it all up.

Rich

[Ecky]

Sure, but timing (from my experience with engine tuning) tends to be worth only a few percent - maybe 5% tops, unless it's very drastically off (tens of degrees). Most engine programs have slightly conservative ignition timing. Propane's flame speed is nearly the same as gasoline's, around 7% faster, which means if an engine computer's timing is slightly conservative for gasoline, it ought to be just right for propane.

Both gasoline vapor and propane vapor burn, rather than explode. If they explode, you have knock, and it tends to damage things. Propane is actually slightly more resistant to exploding.

In terms of ignition timing, at low RPM high load, the ignition timing in my K24 engine was very nearly 0 degrees. I needed to back it away from zero on lower octane fuels, but under ~1250rpm the ignition event was set within a degree or two from zero - because for best mechanical efficiency, you want peak pressure to build up by ~15° or so, where the piston is not just pushing straight down onto a vertical crankshaft. So, the angular time until peak combustion pressure (when a majority of the fuel had burned) was approximately 15 degrees of rotation.

[racprops]

I have not looked into propane or natural gas use in cars, the TRI-Fuel generators are built to run all three so I would guess they do so as best they can...and still big power loses.