Vapor fuel continued desscussion!!

[IamIan]

Originally Posted by Old Mechanic

Would you attribute the 20% improvement to more efficient combustion, or greater throttle opening, or a combination of both in what Percentage?

The test report I read .. didn't specifically break it apart into contributing portions .. verbatim quote (with sited source) attached bellow for others to interpret differently if they wish.

Personally .. my guess .. would be a combination of those you listed and others .. My shoot from the hip guess of the most to least contributing might be something kind of like.

• Improved Efficiency of converting the fuel energy combusted into shaft energy... which would be the net result of numerous others :
  • Reduced throttle losses
  • Improved angle of application
  • Improved synchronization of applied force during cycle.
  • Reduced back pressure.
  • + other more minor influences
• More complete Combustion of fuel chemical energy injected... which is also the net result of numerous others:
  • Improved air / fuel concentration gradient flux.
  • Increased pulse width of combustion event.
  • Improved Spark Plug design for specific application.
  • + other more minor influences
• some other more minor contributions.

[stovie]

ok i just barely got a vapor system running on my jeep. Unfortunately it's got a bad tranny so i can't drive it, which is why i decided to through it on there because it doesn't matter if i blow it up or not. It ran really well other then the idle bypass valve was trying to adjust fuel curve at idle and all.

It was running off of a 5 gallon can with 1.5 gallons in it. so i was wondering how long it should be able to use up 1 gallon of fuel at idle normally. That way if it should idle through 1 gallon in about four hours and it only goes through a few cups then it would give an idea on how much better the fuel economy would be.

I know it would be better to actually drive it around to check fuel economy, but i don't have another tranny for it or the money to get one right now.

[oil pan 4]

Oh so you made a fire bomb.

This is what fuel vapor does:
http://www.kirotv.com/news/news/desi...explode/nbXNt/

[stovie]

First off he used a 55 gallon barrel, who in their right mind would ever think that was ok? All the videos I've seen have always said to take every precaution possible when dealing with gas vapor because it's extremely explosive.

A car will do that now even without the vapor setup, it's just that that idiot made a 55 gallon bomb will the most you usually get is a backfire from the tailpipe or intake, which doesn't usually amount to much because of how little gas is there.

[Hersbird]

He made a bomb and you made a motor capable of running without a load. Did you ever think it might take a 55 gallon drum worth of vapor production to actually make power?

[stovie]

That could of been a possibility had the reason I couldn't go pass 2000 rpm was because it was running too rich. The jeep wouldn't even start at first so I made a little gap between the gas can and supply line so it could suck more air, and it started right up.

Then I could hit higher rpms by allowing more air in, but I didn't have a lot of time to play with it. So there's more then enough fuel, I just need to let more air in. Oh and I was also having issues with the idle bypass so it wouldn't keep a consistent idle.

[oil pan 4]

I think the best way to test fuel vapor is just to go straight to propane. You know it is 100% vaporized. There no possibility of any less than that at room temperature at 1 atmosphere of pressure. Unlike gasoline you can accurately meter propane into the engine.
Most fuel vapor setups just hap hazardly vaporize the gasoline at what ever unpredictable rate according to temperature, atmospheric pressure and volatility of the gasoline being used. Where propane flashes to vapor immediately upon depressurization.
Also a good portion of the chemicals in gasoline do not evaporate.
Now propane may seem like a dangerous on road motor fuel but when done correctly its much more commonly found as a motor fuel out side of the U.S. in south America and Europe. It doesn't seem to be any more dangerous than gasoline when used correctly.

[RustyLugNut]

Originally Posted by oil pan 4

I think the best way to test fuel vapor is just to go straight to propane. You know it is 100% vaporized. There no possibility of any less than that at room temperature at 1 atmosphere of pressure. Unlike gasoline you can accurately meter propane into the engine.
Most fuel vapor setups just hap hazardly vaporize the gasoline at what ever unpredictable rate according to temperature, atmospheric pressure and volatility of the gasoline being used. Where propane flashes to vapor immediately upon depressurization.
Also a good portion of the chemicals in gasoline do not evaporate.
Now propane may seem like a dangerous on road motor fuel but when done correctly its much more commonly found as a motor fuel out side of the U.S. in south America and Europe. It doesn't seem to be any more dangerous than gasoline when used correctly.

I have posted links in the past to the Clackamas, Oregon company that developed a gasoline vaporizer to the point of testing at a California EPA testing facility.

Clackamas engineers' invention improves fuel economy | OregonLive.com

They have measured a 30% fuel economy improvement.

However, notice that they are heating the fuel and air to maintain the stoichiometric balance to keep NOx down. Thus, they have changed the combustion dynamics of the fuel mixture. Fuel vaporization in and of itself is not the cause of increased economy potential. It is the added heating of fuel and air. Contracting the combustion pressure curve results in increased fuel efficiency. With the increased mixture heat, they claimed to be able to reach 50-90% fuel economy gains though NOx pollutants were high at these lean mixtures.

[RustyLugNut]

. . . that needs to be addressed is the idea of increased temperature at lean mixtures.

The charts that have been produced and the discussion that has ensued has mixed up the concepts of flame temperature and mixture (working fluid) temperature.

At part throttle, the flame temperature may be high but the over all mixture temperature may be different dependent on mixture mass and combustion dynamics.

Also, with mixtures richer than lambda, power production is increased even though no more heat is produced as all oxygen is consumed. The power increase is partly a function of the greater specific mass of the working fluid.

At mixtures just lean of lambda, there is a secondary fuel source in the nitrogen if there is enough flame temperature to provide the energy to dissociate the nitrogen gas to gain the exothermic energy in its oxidation to NOx. This is that range around 16:1 AFR that pilots can lean their aero engines for max fuel economy. Beyond that AFR, the specific heat of energy starts dropping and so does the production of NOx.

As your mixtures becomes leaner, as a previous poster noted, unburned hydrocarbons (UBHCs) and carbon monoxide (CO) start increasing as flame irregularities increase. Using in cylinder pressure traces, combustion engineers use a 5% coefficient of variability (COV) as the break point at which flame fronts become unstable by definition ( 5% variation in pressure ).

The vaporization of gasoline is easily attained in modern engines by the time combustion takes place. We can all agree the 98% fuel combustion claimed by most manufacturers for modern engines is an undisputed fact by all but the most uninformed. However, as Stovie is finding out, the total vaporization of the constituents of gasoline is not a trivial undertaking. And, by the time you have used heated fuel, heated air and mechanical turbulence - you have added all the ingredients for a more reactive fuel mixture! Combustion of all the fuel is not the issue, but HOW you combust it is. Attempts to externally vaporize the gasoline fuel bring with it the attendant qualities that make for more rapid combustion at lambda mixtures and increased stability at extremely lean mixtures. Pgfpro and Iveyjh, have work that corroborates this. I think Stovie's work will too.

And I trust Stovie has more than enough clarity of thought to keep from blowing himself up while providing us with continued data of experience.