Alcohol in gas affects mixture

[jrm81bu]

I do also like the hood scoop i'll check out your thread, i think you have to remember that these carbs are set up to run gas only and jetted for that,so when you add a filler,like ethanol that has a lower btu you leaning out the mix, when you run methanol or e85 you have to jet it up,when i was running gocarts i went from gas to methanol i jetted up...a lot up lower btu but higher octaine and more hp and it was fast! 80mph at road America that was plenty fast an a cart for me 😀

You need to make changes to make all the power, no doubt about that at all. You need more than just a jet change with e85 or methanol, larger jets alone won't cut it. But once again ethanol is not an inert filler, it is a fuel. The lower output of the ethanol(btu) has no bearing on the fuel mixture. BTU is nothing more than a measurement of energy. While you a/f mixture can change you effective btu, the btu cannotchange you a/f ratio.

 

[CWPottenger]

Ethanol is neither inert or a filler! Ethanol is a fuel plain and simple.

Ethanol mixes have existed since the very 1st internal combustion engine was designed... The argument against Ethanol is always basically the same and flawed. The concept that an engine can't run Ethanol with out failure is political in nature. Like anything else you do to an engine other changes or tuning will be required. Do you just install a different cam, heads, lifters, induction, pistons, etc and leave everything at stock specs? Obviously NO. Car Mfg all know about ethanol and the requirements to run it at different concentrations and have for decades. Mfg issues with Ethanol are driven by politics telling them what efficiency and emissions they must have and what it cost to do it. Ethanol is just the ball in the middle of these opposing forces.

 

[Clone TIE Pilot]

Ethanol is neither inert or a filler! Ethanol is a fuel plain and simple.

Ethanol mixes have existed since the very 1st internal combustion engine was designed... The argument against Ethanol is always basically the same and flawed. The concept that an engine can't run Ethanol with out failure is political in nature. Like anything else you do to an engine other changes or tuning will be required. Do you just install a different cam, heads, lifters, induction, pistons, etc and leave everything at stock specs? Obviously NO. Car Mfg all know about ethanol and the requirements to run it at different concentrations and have for decades. Mfg issues with Ethanol are driven by politics telling them what efficiency and emissions they must have and what it cost to do it. Ethanol is just the ball in the middle of these opposing forces.

I didn't say it wasn't a fuel. It's a fuel a engine set up for gasoline can't burn very well, so it acts like a inert filler for a gasoline burning engine because it just doesn't burn that well in that motor. However a engine set up for Ethanol will not have any trouble burning it or running on it, but will run very poorly and spark knock badly on pure gasoline. I thought this would be understood in my earlier post by I guess not everyone did understand. A computer controlled flex fuel engine can "detune" itself so it can run on E85, but not that well. Even Flex Fuel motors get poorer MPGs on E85 vs E0 because it is nothing more than a gasoline engine with a fancy control system. A 1970s car is not going to have such a fancy system from the factory. I am not even sure how well a 1980s computer system like the CCC can respond to Ethanol, but a pre 80s car do not have any control systems to react with Ethanol content to alter the tune. Such a motor just runs poorly until the owner manually detunes it so it runs okay, but not at 100%. Now they could build a motor to run on E85 or E100 and get better MPGs than a gasoline motor, but it could not run on E0 or E10 without spark knocking. Just look at the flex fuel diesel motors the old surplus army trucks use, they can burn almost anything at the expense of decreased efficiency. Decades ago with farm tractors, you could order them for either gasoline burning, kerosene burning, distillate (not diesel) burning, etc. The motors were set up with different CR and carb jetting depending on the fuel they were designed to burn. We tried many different fuels over the decades and gasoline and diesel won because they were the easiest fuel to burn.

The issue here is the government forcing a fuel mix into our engines that were not set up for it. This forces us to either detune the motor so they can run with decreased efficiency, rebuild our motors to Ethanol specs like some here have, or just replace the old car with a flex fuel car which is what the govt prefers to increase our GDP.

 

[79wagonator]

This is an interesting thread
Sounds like a job for Mythbusters
Somebody call Jamie and Adam.
I agree with clone tie pilot though.. 😀

 

[jrm81bu]

I didn't say it wasn't a fuel.Well in your flawed a/f ratio mix you took the ethanol completely out of the equation, therefore you are treating it as not a fuel. It's a fuel a engine set up for gasoline can't burn very well, so it acts like a inert filler for a gasoline burning engine because it just doesn't burn that well in that motor.It burns fine just not with as much energy. However a engine set up for Ethanol will not have any trouble burning it or running on it, but will run very poorly and spark knock badly on pure gasoline. I thought this would be understood in my earlier post by I guess not everyone did understand. A computer controlled flex fuel engine can "detune" itself so it can run on E85, but not that well.It wouldn't be de-tuning anything, there is MORE power available from E85.That is just wrong info. The tune is just like any other non flex fueled vehicle, but when it see ethanol in the system it will increase the tune, and will run just fine on either. Even Flex Fuel motors get poorer MPGs on E85 vs E0 because it is nothing more than a gasoline engine with a fancy control system. Again, I can guarantee you have no actual numbers on this. Why? Because NO manufacturer is paying a third party to do MPG testing on their cars running E85. Any MPG numbers posted are based of pure speculation by math.A 1970s car is not going to have such a fancy system from the factory. I am not even sure how well a 1980s computer system like the CCC can respond to Ethanol, but a pre 80s car do not have any control systems to react with Ethanol content to alter the tune. Such a motor just runs poorly until the owner manually detunes it so it runs okay, but not at 100%. Now they could build a motor to run on E85 or E100 and get better MPGs than a gasoline motor, but it could not run on E0 or E10 without spark knocking. Just look at the flex fuel diesel motors the old surplus army trucks use, they can burn almost anything at the expense of decreased efficiency. Decades ago with farm tractors, you could order them for either gasoline burning, kerosene burning, distillate (not diesel) burning, etc. The motors were set up with different CR and carb jetting depending on the fuel they were designed to burn. We tried many different fuels over the decades and gasoline and diesel won because they were the easiest fuel to burn.

The issue here is the government forcing a fuel mix into our engines that were not set up for it. There are alot more vehicles out there prepared to run it(E85) than you think. Computers have been programmed with an alt fuel algorythim since (and I wish I could remember the exact date) around the begining of OBDII.This forces us to either detune the motor so they can run with decreased efficiency, rebuild our motors to Ethanol specs like some here have, There is nothingto rebuild or change in the engine to run ethanol.or just replace the old car with a flex fuel car which is what the govt prefers to increase our GDP.

 

[Clone TIE Pilot]

Well in your flawed a/f ratio mix you took the ethanol completely out of the equation, therefore you are treating it as not a fuel.

A gasoline motor is only burning the light ends of the ethanol and not extracting most of the energy from it. To get a good burn with ethanol you need more CR, it's that simple. My a/f mixture isn't flawed but your arguments are.

It burns fine just not with as much energy.

Only if you have the proper CR for ethanol, gasoline motors don't have high enough CR and therefore need more fuel as a band aid. This is besides the two fuels having different burn rates and mixture ratios.

It wouldn't be de-tuning anything, there is MORE power available from E85.That is just wrong info. The tune is just like any other non flex fueled vehicle, but when it see ethanol in the system it will increase the tune, and will run just fine on either.

There is only more power available because you can run a higher CR than with gasoilne. Flex fuel motors don't have that CR so then run worse and get poorer MPGs because of it. Then have to de-tune form a optimum tune for gasoline to a compromise between ethanol and gasoline such as dumping more fuel into the motor. A 'Stoichiometric' AFR has the correct amount of air and fuel to produce a chemically complete combustion event. For gasoline engines, the stoichiometric, A/F ratio is 14.7:1, which means 14.7 parts of air to one part of fuel. The stoichiometric AFR depends on fuel type-- for alcohol it is 6.4:1 and 14.5:1 for diesel. So ethanol burns at a richer mixture than gasoline, and the computer settles at a tune between the two fuels on a motor not really designed for one of them.

Again, I can guarantee you have no actual numbers on this. Why? Because NO manufacturer is paying a third party to do MPG testing on their cars running E85. Any MPG numbers posted are based of pure speculation by math.

Because math always lies . Of course no manufacturer is paying a third party to do MPG testing because they already know and don't want the public to know what a lame Dr feelgood tactic all of this is with ethanol.

There are alot more vehicles out there prepared to run it(E85) than you think. Computers have been programmed with an alt fuel algorythim since (and I wish I could remember the exact date) around the begining of OBDII.

Again nothing more than a band aid for running a fuel mix with two fuels that burn at different rates and A/F mixtures in a motor not optimized for one of those fuels. It would be better to run 100% of either fuel in a motor optimized for that fuel. Not some screwy mix of the two fuels to line some farmer's pockets.

There is nothing to rebuild or change in the engine to run ethanol.

If you don't mind slightly less power and poorer MPGs that is. Using a fuel in a motor not optimized for that fuel is not going to perform at it's best. To run ethanol properly you need higher CR to get the same power and MPGs as E0 gasoline. Ethanol's only advantage is you can run on higher CRs with it, if you don't have a high enough CR then you will see nothing but disadvantages. The proper CR for ethanol will not allow the use of gasoline since the motor will spark knock badly on gas.

 

[79wagonator]

 

[Clone TIE Pilot]

Pretty much LOL.

 

[gp02a0083]

I think there's a bit of confusion here with all of this. I'll try to explain again from a chemical stand point relating to use to provide work in a mechanical system. First of all lets get on the same page, ethanol by ITSELF is a type of fuel, this is denatured alcohol ( don't go and try drinking this) and had different combustion characteristics than hexane or what is typically used to model "gasoline" is iso-octane. Short chain alcohol's like ethanol (EtOH) have a high tendency to be hydroscopic ( high affinity to absorb water) we all know this is bad when the alcohol is saturated and phases out some water. Gasoline itself is not a one or two part component system, its is referred to as a "BLEND" and comprises of longer (heavier) and shorter (lighter) hydrocarbons with an average chain length being around 8 carbon units. with this being said there are other parts like toluene, X/O/P xylene's , some various benzene's and naphthalene to name a few. The reason for use of ethanol here in the US is due to EPA and emission regulations. Recall back prior to 1975 / 1976, we were using lead in gas and its purpose was to keep valve seats cool and knock down. We found out this was very harmful and the US went with MTBE, nasty stuff and easily leaches into our water tables. So the next and cheapest alternative was ethanol. So history lesson is over, lets think about the combustion reaction of pure iso-octane.

It takes 1 part iso octane with 12.5 parts of oxygen to yield 8 parts Co2 and 9 parts H2O. Or written out here in a typical combustion equation:

(2x) C8H18 + (25X) O2 -----> (16x) CO2 + (18X) H2O

However, there are other substituents / barbiturates in a gasoline blend and formation of others after the combustion (like carbon monoxide), but for the sake of simplicity we will stick with this.
Now if you add ethanol to the combustion, the stoichiometry of the combustion is changed as we have already mentioned in previous posts. The C-O bond energy (78 kcal/mol) is less than the C-C bond (80 kcal/mol) in the isooctane chain in addition the C-H bonds that are 98 kcal/mol. so basically the C-O bonds would be prominent in this case, so more CO2 CO. However the O-H bond is much stronger due to oxygen's electronegative character and requires 110 kcal/mol to break that bond, meaning its stable. By adding the ethanol in a gasoline blend you are theoretically creating more carbon gasses and more water than anything (hence its use by the EPA to reduce emissions) with a slightly lower combustion temperature. With this being said the AFR would need to be adjusted to achieve a textbook combustion.

Now lets talk the work that can be done by the combustion. Diesel engines cannot be used as a fair comparison in this case as it's OTTO cycle is a bit different and primary runs only on combustion and the auto-ignition of the fuel being used. Gasoline engines are that much different being they require an ignition source, so compression is a key factor still in this type of system. However, the compression done by the piston will cause the auto-ignition temperature to change making the air / fuel mixture easier to ignite without much additional energy. I can't say much as far as Flex-fuel vehicles and how they work. I have done my senior thesis on gasoline / alcohol blends from 0% to 20/25%. A 30% decrease in energy is seen when going from 10% to 20%. so in a sense from my experiments in the past, it is proper to say if a system was designed to run on 100% of whatever fuel intended it will run better. However all engines are merely air pumps its just the matter of what fuel and air mixture introduced into the system to get the best output and reliable performance.

Just trying to take a neutral stand point on this topic as many are misinformed, here is a link to a paper produced 1 year later after i did my experiments. This paper going more into depth of different blends and associated mechanical settings (spark/timing). I know i bored a lot of people and hopefully helped educated others.

 

[jrm81bu]

Well in your flawed a/f ratio mix you took the ethanol completely out of the equation, therefore you are treating it as not a fuel.

A gasoline motor is only burning the light ends of the ethanol and not extracting most of the energy from it. To get a good burn with ethanol you need more CR, it's that simple. My a/f mixture isn't flawed but your arguments are.

You cannot take the 15%(in your example) ethanol out of the 1 part fuel, just because you don't think it will burn good enough. And then use that as an example of how it changed the a/f ratio. Like it or not it's there and is a fuel regardles of the burn rate, BTU output or anything and will need to be counted as part of the a/f ratio. So there is where your math is flawed. Period.

It burns fine just not with as much energy.

Only if you have the proper CR for ethanol, gasoline motors don't have high enough CR and therefore need more fuel as a band aid. This is besides the two fuels having different burn rates and mixture ratios.

In thoery you could be looking at incomplete cumbustion, in practice it's actually works better than you think.

It wouldn't be de-tuning anything, there is MORE power available from E85.That is just wrong info. The tune is just like any other non flex fueled vehicle, but when it see ethanol in the system it will increase the tune, and will run just fine on either.

There is only more power available because you can run a higher CR than with gasoilne. Flex fuel motors don't have that CR so then run worse and get poorer MPGs because of it. Then have to de-tune form a optimum tune for gasoline to a compromise between ethanol and gasoline such as dumping more fuel into the motor. A 'Stoichiometric' AFR has the correct amount of air and fuel to produce a chemically complete combustion event. For gasoline engines, the stoichiometric, A/F ratio is 14.7:1, which means 14.7 parts of air to one part of fuel. The stoichiometric AFR depends on fuel type-- for alcohol it is 6.4:1 and 14.5:1 for diesel. So ethanol burns at a richer mixture than gasoline, and the computer settles at a tune between the two fuels on a motor not really designed for one of them.

They don't run worse when on e85. I know of too many people choossing to run e85 even in heavy Suburbans because they run better. Really the stoich ratio doesn't matter at all for the op issue. NO vehicle runs stoich when accelerating. The e85 guys aren't running anywhere near 6.4:1 and that is when they are making power, cruising is above 12:1.

Again, I can guarantee you have no actual numbers on this. Why? Because NO manufacturer is paying a third party to do MPG testing on their cars running E85. Any MPG numbers posted are based of pure speculation by math.

Because math always lies . Of course no manufacturer is paying a third party to do MPG testing because they already know and don't want the public to know what a lame Dr feelgood tactic all of this is with ethanol.

No, it's just cheaper for them to use theoretical math to post a number that no agency is checking. Independent test have shown mpg loss in the single digit percentages, not the 30% they post.

There are alot more vehicles out there prepared to run it(E85) than you think. Computers have been programmed with an alt fuel algorythim since (and I wish I could remember the exact date) around the begining of OBDII.

Again nothing more than a band aid for running a fuel mix with two fuels that burn at different rates and A/F mixtures in a motor not optimized for one of those fuels. It would be better to run 100% of either fuel in a motor optimized for that fuel. Not some screwy mix of the two fuels to line some farmer's pockets.

No, because there would be cold climate issues with e98(highest you will find). The e85 is a good trade off and is still reduced to e70 in some places as cold weather nears. There is also nothing to be gained performance wise from anything much stronger than e85. Sounds like prejudice against farmers. If you produced something that all of a sudden had two use from the same exact product wouldn't you feel it was worth more. However none of the money will ever get back to the individual farmer. Besides ethanol doesn't just come from corn.

There is nothing to rebuild or change in the engine to run ethanol.

If you don't mind slightly less power and poorer MPGs that is. Using a fuel in a motor not optimized for that fuel is not going to perform at it's best. To run ethanol properly you need higher CR to get the same power and MPGs as E0 gasoline. Ethanol's only advantage is you can run on higher CRs with it, if you don't have a high enough CR then you will see nothing but disadvantages. The proper CR for ethanol will not allow the use of gasoline since the motor will spark knock badly on gas.

You can't be more wrong here. There is nothing optimized for ethanol use in my combo yet with the mix I'm running i've lost zero power and will got to a higher ratio soon. There has been some people that have switched to E85 and didn't pick up any time or very little. But I haven't heard of any other than Chris that has lost time. There is also the advantage to running cooler. It would help to be consistant for a bracket car, even one that isn't going for all out power. To take full advantage of it yes, higher compression would be good. Plenty of people pay higher prices for 93 or even 100 octane fuel, or even race fuel. Being able to run the same car on fuel that cost less than 87 is great. Why would you be against that.

You or anyone else can disagree with me all you want, but i'm actually using it, and will post any and all results. Regardless, i really think it's here to stay, so you might want to look at how to make good use of it.