This is a subject I have been long interested in, and have done a fair amount of research into. I was trying to determine if such a super-carburetor could exist, or did exist, and if it did, why is it not in widespread use in cars today?
What I found is the following:
1) Some cars are claimed to have run with a super-carburetor, even large V-8 engines, some claim 100 miles per gallon (mpg), some claim up to 200 mpg. There were eyewitnesses to some demonstrations, and technical experts who examined the cars carefully for hidden fuel tanks. None were found.
2) At least one of the super-carburetors used a form of thermal catalytic cracking, aka TCC, at least that is the term reported.
3) The super-carburetors declined in performance over time, and eventually gas mileage reverted back to the normal level.
4) Inventors and advocates accused the oil companies of placing an additive in gasoline that would deactivate the TCC super-carburetor. This was viewed as a malicious effort to discredit the inventors.
I have some specialized knowledge when it comes to gasoline, oil cracking processes both thermal and catalytic, and how oil companies make gasoline. I write this to shed some light on why the TCC carburetors do not work, and how oil companies did nothing nefarious or malicious to cause a super-carburetor to fail.
First, a little background on gasoline. Gasoline is made up of many petroleum compounds, ranging from iso-butane through carbon chains with 11 or 12 carbons. The average length of a carbon chain in gasoline is around 8 to 9. Gasoline is added to an engine along with air, on the piston down-stroke. The air/gasoline mixture is compressed on the piston up-stroke, and ignited by a spark plug firing just before the piston reaches the top of its stroke. The gasoline reacts chemically with the oxygen in the air, burns, and produces heat which increases the pressure above the piston. The increased pressure pushes the piston back down on the power stroke. Not all of the gasoline is burned, however, and that is where the super-carburetor enters the picture.
In theory, if more oxygen is added, and the gasoline molecules were not 8 to 10 carbon chains long, there would be more chemical reaction in the combustion chamber. That would release more heat, and less gasoline would be required.
Now, to digress a bit and discuss cracking of oil. A thermal cracker is a process unit in a refinery that receives a heavy oil, much heavier than gasoline, normally known as gas oil. Whereas gasoline has 8 to 9 carbons in each molecule, gas oil would have on the order of 30 t0 40 carbons per molecule. Gas oil in a clear jar is visually much like lubricating oil that service stations pour into the engine's crankcase.
The thermal cracker heats the gas oil to a high temperature, perhaps 900 to 950 degrees F, and then allows the very hot oil to flow into a separator vessel. The hot oil literally cracks apart, so that the long carbon chains break into smaller chains. The smaller chains are not all the same, but some have 2 carbons, others 3, 4, and so on up to about 20. Each breaking point in the chains also results in a chemical double-bond, also known as an olefin in chemistry. One of the by-products of the cracking process is very high-carbon number chains that resemble asphalt or coal. These compounds, and they are key to understanding why super-carburetors do not work for long, are called petroleum coke.
A catalytic cracker is somewhat similar to the thermal cracker, except that a very fine catalyst that resembles fine sand is used. The catalyst is heated to around 1100 degrees F, then mixed with the gas oil in a fluidized reactor. Steam is injected upward to provide the fluidizing. The gas oil cracks, but the catalyst affects the cracking so that more molecules form in the gasoline range of 8 to 9 carbons compared to thermal cracking. Also, petroleum coke forms and coats the catalyst particles until they are dark gray, or black. In the catalytic cracker, the spent catalyst, which contains the coke coating, is processed in a regenerator vessel where the coke is burned off by injecting hot air. This heats the catalyst also, and the regenerated catalyst without very much coke is recirculated back to the feed section to react with more gas oil.
From what I have read about the TCC super-carburetors, they used a heated tube filled with a special sand to crack the gasoline into smaller carbon chains. The smaller chains would have carbon numbers ranging from 2 to about 5, and would have many olefins. The flow out of the TCC tube would also be very hot. The hot, olefinic, short-carbon-number material was then mixed with air and directed into the engine.
I could not determine how the super-carburetor TCC reactor tube was heated, but it may have been heated with hot exhaust plus an electric heater that used power from the alternator or generator. The very hot fuel/air mixture would burn even hotter in the engine, thus providing more power. Less fuel would be required, also. I suspect that achieving 200 miles per gallon would be quite difficult in a big V-8 engine, as that would represent a 10-fold improvement over 20 miles per gallon. Still, it might have happened.
But what slowly decreased the TCC super-carburetor performance was the petroleum coke, the black residue that would coat the particles of sand in the TCC tube. Once the coke residue coated the sand, the cracking would cease and no benefit would be seen.
Some are probably asking why don't the oil companies just crack the gasoline for us, and sell it that way? There are a couple of reasons. First, olefinic hydrocarbons with 3, 4, and 5 carbons in the chain will not remain liquid in hot weather. Most of the liquid would evaporate, and a vapor cannot be pumped by the fuel pump. This causes vapor lock, and the car will quit running. Second, olefinic hydrocarbons do not remain in that form over long periods of time. Instead, the olefins tend to combine with each other and form a gummy substance. This gummy substance plugs up fuel lines, fuel filters, fuel tanks, and carburetor surfaces.
Another question is why don't car companies install that fuel heater, and use electric power from the alternator to vaporize and heat the gasoline before it enters the carburetor, or the fuel injection nozzle on modern cars? The most obvious answer is safety. A fuel heater would leak eventually, and hot gasoline would or could explode in the engine compartment.
A final comment, as one source I read stated the super-carburetors worked even better on rainy days, when running the car in the rain. What likely happened there is that the air intake would draw in a few fine drops of rain with the air, mix this with the hot cracked gasoline components, and that would enter the engine. After combustion in the engine, the small water droplets would vaporize and expand as water vapor, adding somewhat to the pressure in the cylinder.
This only works for a short time, as the water droplets tends to plug up the air filter where trapped dirt particles turn to mud.
I hope this helps to explain super-carburetors.
My knowledge of refining processes, and gasoline, and engines, comes from my engineering days in refineries, and having a bachelor's degree in chemical engineering.
Roger E. Sowell, Esq.
Contact Mr. Sowell at his legal website.