Fuel Vapor

racprops's picture

I may have placed this in the wrong thread:

Some bad news:

The Truth About Vapor Fuel
Like many others, we have heard stories of vapor systems that achieved incredible mileage. We have spent the last seven years, and a great deal of our client’s money, to determine what actual benefit, if any, there is to fuel vapor technology.

We found that fully vaporizing fuel prior to entering the combustion chamber is beneficial in several ways including a more homogenous fuel-air mix and a faster flame speed. Both of those proved to be very important when we were in a lean-burn condition. We were able to safely run a standard V-8 engine on fuel vapor at air to fuel ratios up to 28-1 rather than the standard 14.7-1.

The impact of lean-burn combustion on fuel economy is well documented. Several of the major automakers experimented with lean-burn during the nineties and into this century. There are credible reports of as much as a 50% increase in fuel economy. We were also able to demonstrate the same benefit using a vapor fuel system in a lean-burn mode.

So what happened to that technology? The inability of current catalytic converters (CATS) to remove Oxides of Nitrogen (NOx) from the exhaust has prevented its use. It seems the CATS work fine at the normal air to fuel ratio but cannot remove NOx in a lean condition. A great deal of time and money has been spent in the last decade, on a variety of theories, attempting to solve the NOx issue.

Although we, and much of the automotive world, found the best fuel economy is achieved at an air to fuel ratio of about 20-1 the NOx levels decreased to acceptable levels at about 28-1. The fuel vapor system allowed us to run that lean without requiring the complicated and expensive engine modifications of the direct injection systems. The problem everyone seems to have experienced was a significant loss of power during that extreme lean condition. A more efficient combustion was needed if any of the benefit of lean-burn was to be realized.

Homogeneous Charge Compression Ignition (HCCI) and Autoignition are two of the most touted current technologies that may fit the bill. General Motors and Ford have both announced plans to produce vehicles that will utilize HCCI technology. We agree but this is where we have taken a different approach. It appears the rest of the auto industry has approached HCCI and Autoignition as extensions of the lean-burn effort, but we have not.

The HCCI efforts of others appear to still be based on diluting the amount of fuel used by supplying more air to the charge resulting in a lean fuel to air condition. The greatly improved efficiency of the HCCI combustion allows their technology to work at higher air to fuel ratios where NOx is not as much an issue but not without sacrificing power. Automakers are reporting their HCCI operation will be used at light loads and lower speeds. They are further predicting an improvement in fuel economy of between 15 and 30%.

Vapor Fuel Technologies, LLC (VFT) has a system that utilizes the benefit of HCCI type combustion without creating the NOx problem. Vaporizing the fuel and mixing with heated air prior to entering the combustion chamber accomplish the dilution of the fuel air charge. This process accomplishes the dilution by thermal expansion rather than adding air. The heated air and vaporized fuel simply occupy more space, per pound, within the combustion chamber.

Dilution by thermal expansion allows the VFT System to operate at the standard, 14.7-1, air to fuel ratio allowing the catalytic converter to work correctly. The heating process also creates the conditions for a spark initiated autoignition combustion. As the fuel air charge is compressed it approaches the point of autoignition. When the spark plug ignites, the in-cylinder pressure and temperature rapidly increases. The homogeneous vapor mixture rapidly combusts in a series of autoignition events.

The result of the technology is an independently verified increase of over 30% in fuel economy. An EPA recognized and California Air Resources Board (CARB) certified laboratory ran a series of tests and has verified the fuel economy improvement.

As for the original question about any real improvement due to vaporizing fuel, we have not discovered any 200mpg carburetors but there are proven benefits

Ok, When Pogue built his vaporized carb, oil companies distilled gas so it consisted of mostly short chain hydrocarbon molecules and was known as well head gas. These light hydrocarbons vaporized easily, lending to the high mileage that he acchieved. Ogle who got 100 mpg also used well head gas.

Shortly after Pogue went public with his carb, the oil companies decided it was necessary to begin refining the gas thru catalytic cracking, plus the addition of lead to the gas( I suspect) led to the failure of vaporized carbs as when the gas vaporized the lead would be left to coat the heat exchanging surfaces of the carb, and effectively insulate them.

Gas now is comprised of over 4000 hydrocarbon chain lengths; each becoming gaseous at a different temperature. There are also additives that vaporize at over 1000 degrees, that like lead did , will coat heat exchanging surfaces, and insulate them over time , rendering the vaporizer ineffective.

There was one class of college students that replicated the Ogle system and it did perform as his did at first. Eventually the system failed and they also found that they couldn't add any new fuel to the system. Upon removal of the gas tank they realized that it was filled with sludge and corrosive heavy end hydrocarbons that had not vaporized while they were driving.

This and the fact that there are more then 26 different blends of gas across the country that would have to be compensated for, explains a good part of why the catalytic converter was made mandatory on every new car produced. Unless one is willing to gamble with a device that produces under the hood temps of 1500 degrees before combustion, there is not much chance of fully vaporizing and cracking the fuel to produce high mileage.

Those that had intial sucess with their cat crackers and got 70-100+mpg have stated that the end resulting gas that was actually burned for power had the consistancy of methane.

Commits?? Answers??

Rich: There is never enought time for me to do what I want to do.racprops
Super Carb Member