[Isaac Zachary]

Originally Posted by racprops

True to a point…none the less once in a vapor state some action is needed to cause a change into another state.

Steam IS the “smoke” true fully vapor would be transparent, fully in a full vapor state. My idea of a system would be feeding hot vapor directly into the intake allowing very little time to cool down.

Extremely wishful thinking. Taking two mixes of gases at extremely different temperatures and mixing them enough for them to burn at all in a combustion chamber and doing so without giving them enough time to settle to a similar temperature is... for lack of a better word and with all due respect, impossible.

Intakes aren't instant transportation devices. Air and fuel stops and starts, stops and starts as each intake valve opens and closes. It then has to go through the intake cycle and then the compression cycle. At what point are you injecting the fuel so fast it doesn't have time to condensate? Is this direct gas injection that you're thinking of? Maybe only then could gasoline stay in a gaseous state if injected exactly as combustion starts. Other than that, its and the air's temperatures are going to quickly find an equilibrium.

Originally Posted by racprops

Gasoline has the most bang for your buck. Vapor gasoline It also has a high vapor density, which means it produces a lot of vapor compared to other combustible liquids.

Um, I still don't get your point. Forget any other types of fuel and focus only on liquid gasoline vs. vaporized gasoline. How much energy is stored in a gallon of liquid gasoline? How much is stored in a gallon of gasoline vapor? How much air and fuel can a cylinder with a displacement of half a liter inhale every intake stroke? How much of that is air and how much is fuel?

Originally Posted by racprops

The flash point of a volatile material is the lowest temperature needed to evaporate enough fluid to form a combustible concentration of gas. Gasoline has a flash point of -45°F and an auto-ignition temperature of 536°F.

But you can't have every last drop of gasoline in a container vaporized at -45° F. It needs to be at around 200° C or 395° F at atmospheric pressure to completely boil it. Then you start compressing it and its boiling/condensing temperature will also go up meaning some of it will condense if you get it to just 200° C or 395° F before compressing it, so it has to be even hotter in order to not condense.

What's the point of boiling gasoline if some of it is going to just condense right back into a liquid?

Originally Posted by racprops

Burning gasoline vapor can cause an explosion.

On the other hand IF the claims are true and gasoline vapor explodes then it “burn” cycle may be too short to allow quenching…it might combust too fast for that action.

Please research what detonation is.

There are three ways you could potentially burn fuel in a combustion chamber. The conventional way is to do so with a flame front. Flame starts at spark plug and works it's way out like an inflating balloon. This is why we need advanced spark ignition of course.

Another way is to make it all burn up at once, preferably at top dead center. But that needs to be done very precisely, evenly and at exactly the same time and is extremely difficult to pull off. Only Mazda, that I know of, has a spark controlled compression ignition engine that basically does this under certain circumstances. Note that it's the compression that ignites all the fuel quickly, not the spark plug itself.

The third way is to end up with a pocket of fuel and air exploding out of sync with the rest of the combustion chamber. This is mainly caused from lean pockets with less fuel droplets that can absorb the heat as compression from the expanding flame front pushes in on the rest of the unburnt mix. When this happens you get detonation, a sonic pressure wave that results from that small pocket rapidly expanding instead of either gradually, with a flame front, or in sync with the rest of the combustion chamber, as in the case of homogenous compression ignition. The result is the sonic pressure wave pushes hot combustion gases into the metal which causes them to exchange heat very quickly. You lose power because a lot of heat gets into the metal and you also quickly start liquifying metal. This is what causes you to punch holes right through your pistons and causes you to bend rods.

Note that detonation is also something that can be a problem in propane and natural gas engines. These also like having a flame front move from the spark plug out to the edges of the combustion chamber over the course of several, if not dozens of degrees of crankshaft rotation. Just because it's a gas does not mean it's easy to make it all explode instantly at a precise moment.

Originally Posted by racprops

A ICE is a fairly effect air pump, there is a large amount of air being drawn in, gasoline vapor at say 200C is already working in a 100C engine compartment. I don’t think it will cause any problem in a few seconds as it is fed into the engine.

I don't see what that has to do with what I was saying, but I think I can agree to a point on that.

Originally Posted by racprops

Two questions I cannot find answers to:

How much energy in gasoline vapor?

I believe IF I can meter the same amount energy in gasoline vapor like 30% of what normally would be fed into the ICE it would product the same power as it does on its normal system.

And

Is gasoline still burning in the exhaust manifold?

I believe it is as I have read it does in the past.

Also if combustion is completed within the chamber that there would be no need of the cats.

Gas ICEs are still rated at on 30/35% effectent.

Rich

How much energy is in gasoline vapor?
At 200° C my rough calculations tell me it's about 2,000 times less dense than in liquid state. So 2,000 times less energy. In other words, you need about 2,000 times more gas vapor to get the same power as liquid gasoline.

Does fuel still burn in the exhaust? No. Yes. it depends.

With most modern engines the answer is no. Engineers are getting better and better at getting the fuel to burn up quickly, long before the exhaust stroke. Nearly all the fuel left over that burns up in the catalytic converter is from quench, not flame speed.

Of course if you can make it burn up even faster then it can be better. It's best to have it all burnt up as close to TDC as possible, as the top part of the stroke is the part where most of the energy from the already burnt fuel is extracted.