Alcohol (let's talk pure ethanol here) has a lower caloric content than, say, gasoline, which only means that a given weight of fuel produces less calories. So presumably if you fill up your Ford Expedition with ethanol, you'll get 5 mpg instead of 7 mpg.

However, alcohol has some up sides to it that gasoline can't easily compete with:

Higher Performance. Alcohol is about 150 octane or so -- nearly twice as knock-resistant as gasoline (~87-90 octane.) That means you can engineer engines differently: think about an alcohol engine running at a compression ratio of 18-20:1, or lots of boost Higher compression ratios buy you higher efficiencies: one of the reasons diesel engines are more fuel-efficient than gasoline engines. That's why race cars tend to use alcohol and other alternative fuels. This is the big win, where the engineers can make up for the lower caloric content.

Passing Emissions. Alcohol burns much more cleanly than gasoline. NOx, HC and CO emissions are far lower. Most of what you get from burning alcohol is CO2 and water. BTW if you convert you vehicle to run on alcohol it qualifies under the alternative fuel law. Which lets you get rid of most of the equipment, which since it's cleaner burning in the first place you don't need anyways.
California HotRods run alcohol so they can run the fancy blowers & such.

Because alcohol burns so clean, maintenance costs are much lower for an engine burning alcohol than for the same engine burning gasoline. Engine life should be longer as well. This is actually something of a problem for alcohol conversions -- alcohol's solvent effect tends to dissolve old varnish, gum, filth and dirt in existing engines converted to gasoline and loosen things up.

Alcohol's Down Sides

You knew there had to be some, right? They are mostly minor.

Cold starts are more difficult. Alcohol doesn't vaporize quite as easily as gasoline, so cold starts are more difficult. Some sort of preheater (glow plugs?) would be handy.

Corrosive. Alcohol is corrosive to some metals as well as synthetic rubbers. The fuel system needs to be nylon or other alcohol resistant plastic. You also might want to due what CART & IRL teams do, "pickle" the engine. This involves running gasoline through it, after the cars come off the track.

Conversion of an existing engine to alcohol is pretty straight forward job. The fuel system needs to be made alcohol resistant. If carburated, the jets need to be bigger. If it's a slightly more modern engine, the fuel-injection system probably needs to be reprogrammed (and possibly different injectors.)

Why we haven't converted to alcohol? That's a very good question, don't you think?

President Carter was pushing for that 25 years ago. Conversion would accomplish at least three good things: (1) we stop being dependent on a foreign-controlled resource and (2) we support family farmers -- the very people for whom politicians love to trumpet concern about at election time -- and (3) we cut air pollution. A lot. Item number one, of course, has huge implications for national security and foreign policy. The other two are slightly more prosaic, but they have other side effects affecting public health and the way we develop this country in which we live.

Our failure to convert couldn't possible have anything to do with the amount of money contributed by the oil companies to politicians of all stripes, could it? See the oil company lackeys currently in office for details.

 

Brazil had a program going through the 80's and early 90's to encourage use of ethanol. They subsidized its use by increasing taxes on gasoline, thus encouraging people to buy alcohol burning vehicles to take advantage of the lower fuel costs. Since Brazil is a major producer of sugar cain, ethanol was a logical choice for a fuel alternative to gasoline.

Their alcohol burning vehicles used many of the ideas that you mentioned here. The compression ratios were around 12-13:1 which alleviated some but not all of the fuel economy penalty. The performance of the alcohol motors was quite spirited for displacements typically under 2.0L. The cold start issues were addressed by injecting gasoline into the carb during a cold start. The gasoline was contained in a small auxiliary tank.

It all seemed like it worked well to me (at least from what I could tell by my limited visits there), but the program phased out in the early 90's. I'm not sure if they still encourage the use of ethanol fuel there or not. I think the demise was the opening of the Brazilian economy to foreign trade (imports had been banned previously) and the importing of more competitive gasoline powered imports. I also know that it takes a great deal of energy to distill alcohol which may be another draw back. The net energy gain may not be that great.

The slow but sure embracing of gasohol and flex fuel vehicles may be the start of bigger things to come. Some of it comes under the guise of cleaner air, but I think a lot of it comes from the influence of the farm lobbies.

 

I'm into Sprint car racing. Where Methanol is the only fuel. That is why I have had several race machines powered by alky. I have been able to get serious hot rods to pass the sniffer test on methanol.

The midwest corn farmer lobby wasn't big enough to get alky blends nation wide. I do buy Gasahol when I'm in states that sell it and from time to time I have run 25% blends through my Vette is I know that I'm going to use it all up that day

 

I think the problem with alcohol is the BTU. As far as I know, alcohol has a lower BTU, and you have to use quite a bit more alcohol than gasoline to fuel a given level of horsepower. I believe that most racers who run alcohol, use it for it's higher octane rating, and it's lower cost over high octane "race" gas. I might be wrong, but that was how I understood it.
Tony

Btu (British Thermal Unit): One of the two (watt-hours is the other) standard units of measure (IP System) for the amount of energy consumed by a process, the amount of energy transferred from one location to another, or the amount of embodied energy (such as the heat content of fuels). Specifically, it is the amount of energy required to raise the temperature of one pound of water by one degree Fahrenheit. The term 'kBtu' stands for "kiloBtu" or 1,000 Btu. The term of 'MBtu' stands for "MegaBtu" or 1,000,000 Btu. One Btu is equal to 0.293 watt-hours (Wh).

 

Methanol is ruffly $2.00 per gallon. But you burn twice as much. So it's more than the local 105 octane Sunoco $3.86 at the gas station. The real gain is the cooling. On a 90 degree day without a cooling system and just water in the heads with a puke can, you would have to run it in the stagging lanes to get heat in it before doing a burn out. At WOT ice forms on the injectors. Blown alky motors form ice all over the intake.

I also read somewhere that they took a typical 15-1 C/R race 358 ci and when they changed the fuel to Meth they got @4% more hp.

 

I was always under the impression that alcohol burned at a slower rate necessating that the timing be advanced more than with gas. For performance we have always been taught that faster and more complete flame travel in the combustion chamber equalled more power. Of course I'm not a chemical engineer, so don't stone me if I'm wrong. It just seems that alcohol has never turned into the magic formula to answer our energy consumption problems. Of course we can all still hope that that magic is just around the corner, Can't we? Hershey :)

 

Back in college, we built alternative fuel vehicles. One of them was a Beretta which ran on Methanol. We were able recoup the lost BTUs by taking advantage of the higher octane by turbocharging the engine. The bonus was good emissions and cheaper cost (methanol was much cheaper than gas per gallon). The down side was the high corrosiveness, bad cold start, and loss of mpg. So the car had poor cold start in winter and either had a limited distance range or required a very large gas tank. On the safety side, the methanol burned with a mostly clear flame and was potentially more of an explosion risk in the gas tank.

I think the bigger problem is infrastructure. Other viable alternative fuels have such as CNG have been available as well but there are not enough fueling stations for the public consumer. Until the infrastructure can support it, any alternative fuel vehicle probably won't fly except for fleet vehicles.

As for me, I'm all for fuel cells if we can get hydrogren pumping stations.

 

You guys have me completely interested in this topic! im running a carb'ed C4 vette in smog **** california and would love to become an alternative fuel vehicle. My town has places everywhere to get alcohol fuel and would be no big deal. Can someone give more info on ethanol/methanol (which one is used in a alcohol motor) and some more drawbacks to the conversion and the everyday use of it in a daily driver????

 

Ethanol is the better fuel - less corrosive and it doesn't absorb water out of the air as fast as methanol. The only problem with ethanol is it is controlled by the ATF. and is federaly taxed and regulated.

Methanol - If you allow it to sit in your aluminum carb, injectors, pumps, fuel rails. It starts to turn the aluminum into white powder. All storage containers have to be sealed because it will take the water right out of the air. All these problems are when you get above the 25% level.

On a alky drag motor you have to dump it all blow it out with air and take apart the fittings and spray it all down with WD-40. to be able to store the car for the next drag event.

Cold starts - thats why you see the crew chief with a squirt bottle of gasoline before you even rotate the motor. I got tired of doing the dish soap bottle of gas down the injection tube trick. So we ran a plummed in a small gravity fed gas tank with a cable opened barrel valve. After we made ours I started seeing all kinds of variations showing up at the drags.

Any car with hydrocarbon or CO sniffer problems will pass because alky burns and only makes water and co2


[Modified by gkull, 12:04 PM 10/12/2001]

 

I was wondering....couldn't someone have his gas tank filled with normal gas and have a fuel cell filled with alcohol, setup a switch (2 pumps) to switch from one to the other? And even with a programmable FI system, could advance timing and stuff?

 

Chevy actually made a car with that option.

Actually is was water injection for the Turbo Corvairs. You had to mix a little alcohol in to keep it from freazing. The pump went on under high boost.

Runny it on alky, even for just an afternoon, sounds like a solution for those who can't seem to pass the sniffer test.

 

gkull - Do thoes alky motors put out noxious fumes?
I've heard that they have a stink factor.
One more thing to add - bumping up the compression that high may be hard on the bottom end & cylinder walls. I think you would need a good 4 bolt block & forged crank/pistons.




[Modified by 71coupe, 10:26 AM 10/12/2001]

 

Well actually if my understand is correct, its not the pressure of the mix that creates a problem to the hardware but the force of the detonation. So if you havem a 300hp engine, bump it up to 15:1 making 350hp, it won't create more stress than an engine that already does 350hp with a low cr. Maybe I'm just wrong tho. lol.

 

well then how much per gallon is ethanol normally run? and is it an easy conversion to goto ethanol?

 

Here's some links
CALIFORNIA'S ALTERNATIVE FUEL AND HIGH EFFICIENCY VEHICLE PROGRAMS
http://www.energy.ca.gov/afvs/

Alcohol Fuels -- Ethanol and Methanol
Fuel Availability & Price
http://www.energy.ca.gov/reports/afvguide.html#500

ethanol / methanol vehicles
http://www.consumerenergycenter.com/...v/ethanol.html

cleancarmaps.com. to fin Find alternative fuel vehicle refueling sites throughout California
http://www.cleancarmaps.com/cgi-bin/...nect?link=find

forgot one
http://www.methanol.org/


[Modified by BrianCunningham, 3:55 PM 10/12/2001]

 

noxious fumes! The richer you run the more raw fuel the worse it gets. We tried 40% nitromethane and thats when people in the staging lanes ask you if you would shut it off :lol:

It's like anything. I kind of like the noise and smell of race gas in the pits. Much better than normal pump gas. But went your up close to alky or nitro cars :U You will also be able to tell at 25% meth 75% gas if you know what it is.

CarbedC4 - just kind of forget about ethanol. In your case I would be using a separate fuel cell for use with NO2. Fill that tank with Methanol. There are additives which can keep methanol suspended in gasoline above the 25% mark. It's the same idea as saturation point. Like you can add only 1 pound of sugar to a gallon of water and dissolve it all. You add anymore sugar without additional heat and it will just sit on the bottom.

Another thing I see being used more and more is propane/NO2 injection.

 

Here's an interesting post about a guy switching his 14-71 blown 572 boat engine to alcohol :eek:

http://free.hotboat.net/ubb/Forum3/HTML/000100.html

 

Ok, once this alcohol conversion is done, how do i get my car smog exempt here in california? people are telling me itll fall under the alternative fuel act thing but how do you go about getting your car exempted from smog?

 

anyone have any knowledge or info on the process of getting a car smog exempted once it converts to alcohol???????

 

Did you try asking the California Commision above?