what changes in a gas engine to run 85-Ethanol?

General Motors Launches Bio-Ethanol Initiative

Is the gas engine drastically different? Or just tuned to be more efficient when using the 85-Ethanol mix?

Also, on a related question: Have you guys head/read about the scientist in Europe that has done extensive investigation that (according to him) you spend more fosil fule energy to make 85-Ethanol than just plain gasoline?

Will

Going by memory.....

To use e85 AND normal gasoline you need to be able to sense the amount of alcohol in the gas and change the fuel mixture to match. This is because the mixture varies from tank to tank. if you have a 10 gallon tank that's 1/2 full of gas and add 5 gallons of e85, you have e42.5 That changes the proper fuel mixture ratios as well as the performance.

There are also parts (seals, lines and sensors) that can be eaten by the alcohol, so the proper parts must be installed.

I think that's about it.

Daniel

Cool - thanks Daniel

Will

Daniel is correct in saying that E85 is more corrosive than straight gasoline. The flex-fuel engines from Ford and GM in the 1990s used all stainless steel components, except the fuel tank, which was a lacquer lined tank. GM's current crop of tanks are stainless though.

Having said that, I have friends who live in AZ that run E85 in unmodified vehicles and haven't had problems except rough idle. This isn't something I'd do to a new fuel-injected vehicle though, because replacing the rubber seals and such can add up to a ton of $ if they turn to dust.

As far as the air/fuel ratio, running E85 is within the realm of a modern fuel injection system. The PCM ("black box") will pick up the alcohol content in the form of additional oxygen content in the exhaust gas, and will compensate by adding more fuel. In a 1998+ car (USA only) the ignition advance curve will advance up to the area appropriate for E85. E85 has a higher motor octane rating than most pump gasolines, so at highway cruising speeds the lack of knock sensor feedback will allow advance of the ignition timing. That higher motor octane number won't do much in terms of acceleration or RPM transisions though. (Transient octane is the "research" octane value... USA pump gas octane ratings, or antiknock index, is calculated by R+M/2... you've seen this on the pump before I'm sure.)

Ethanol is a volatile fuel very similar to gasoline, meaning your engine should be able to operate on it without too much difficulty. Henry Ford was using ethanol in his cars almost from the very beginning.

As said above, it has a corrosive effect on rubber seals and other metal parts, so those need to be modified or protected (by using synthetics or stainless steel, etc.).

Both the U.S. and Brazil make automobiles (GM & Ford in both countries) that can run on a flexible mixture of gasoline and ethanol. Our latest computer controlled, fuel injected engines make this easier than ever before. In Brazil, they use a simple oxygen sensor on the exhaust side to sense the fuel mixture and adjust the settings for optimum combustion allowing a mix anywhere between 0 and 100% ethanol. The sensor is already there for emissions controls. I've seen it quoted a number of places that it only costs $150 at the factory to make any gasoline engine a flex fuel engine.

The EPA does not recommend converting existing cars that are not already flex fuel to burn E85 (they worry the emissions won't be right). There are already something like 5 million vehicles on the road in the U.S. that are flex fuel adapted at the factory.

The most famous opponent of the energy situation for ethanol is David Pimental of Cornel University. He has tried to add in every conceivable bit of energy needed to grow corn and turn it into ethanol in an effort to discredit the use of corn. I understand he includes the energy to make the farm machinery, the gasoline that ethanol factory workers use to communte to work and even the lunches that are consumed when they are at work. Recently another researcher, Tad W. Patzek from UC Berkeley has revisited Pimental's work and now travels around the U.S. speaking out against ethanol.

The official USDA study of ethanol shows a positive gain in energy (from the sun when the kernals were produced) of 1 unit in producing 1.64 units out (1:1.64). That includes planting, fertilizing, harvesting and converting the corn to ethanol. Corn is a "high input" crop meaning that it needs soil tilling, lots of fertilizer for high yields, pesticides, herbicides, etc. Even with that high input, it has a positive gain in energy.

Corn is not the best feedstock for ethanol.

You may have heard the President's State Of The Union speech where he mentions switchgrass. Switchgrass can be converted to fuel in a variety of ways including enzymes to "digest" the cellulose into sugars that can then be fermented into alcohol (ethanol). Switchgrass is a very "low input" crop. It is native to the U.S. and is pest resistant, drought resistant and actually builds the soil. It is a perennial that does not need to be replanted. Its roots reach down 6-10 feet in the soil once it is established. It brings up nutrients from the deep clay. If about a third of the plant is left after harvest, it will build up top soil year after year instead of depleting the top soil as other crops like corn do.

Corn ethanol is only a place to get started with a renewable substitute for gasoline. It does have a positive energy balance (in spite of Pimental's calculations). However, even if we used every last acre of corn for ethanol, we'd still only replace about 12.5% of our gasoline with it. Corn yields about 371 gallons of fuel per acre per year. Switchgrass is estimated to yield about 1000-1500 gallons per acre per year (still being studied). The energy balance for switchgrass is estimated to be 1:4 (a much stronger energy gain than corn).

See my chart:



You can find a lot of information on using E85 (85% ethanol) at this forum:

http://e85forum.com/viewforum.php?f=1

Just about every car on the road today can run 10% ethanol (E10) now. 77% of all of the gasoline sold in Iowa is E10. We've been using it for years with no problems in just regular automobiles with no modifications what-so-ever.

They did a segment on ethenol on a recent science friday (podcast available) and they talked about both corn and switchgrass, but most interestingly they talked about the amount of burning of waste cellulose that we do. Something like 30% of a tree run through a lumberyard or other such processing ends in unusable waste that is usually just burned. When it could be fermented into the good stuff.

They dont have any real numbers as to how much of this is available, but shirt sleeve calculations make it plenty to create a viable business in recycling the stuff.

Lastly they did have numbers on the amount of acreage in the US that is in an area that could grow switchgrass or other cellulose rich plants (as opposed to like corn) whos owner farmers are currently being paid to not plant on and it's more than enough to meet all the needs for ethenol.

I'd say that between soy oil for bio diesel and cellulose for the regular gas engines around we could do this in not that many years.

scott.cr, ikendu, James_S - thanks so much for your detailed responces :bow:

Definitely worth reading!

Will

IIRC one other adjustment in the calibration has to do with E85 not vaporizing as easily as gasoline in cold weather. In Arizona it might not be an issue but in MN or other parts north it might be a problem.

It should be noted that ALL cars can run 10% ethanon with no problem. Modern cars can probably run a reasonable percentage (I'd guess close to 50%) with few issues. One thing to note is that Ethanol has 67% of the specific energy - which means that all things being equal, your fuel economy will be worse in mpg for E85 than 100% gas.

The changes would not be cost worthy to modify a modern car to run on it.
Also, unless you can get e85 for dirt cheap, or you only car about using less fossel fuels and helping out farmers, you will end up paying more for it because you get less MPG from ethanol.

Here they sell it only about 10 cents cheaper than regular gas. With the lost miles you get from it, you actually are paying more than if you would of filled up with normal gas.
Even 10% ethanol can end up costing you more than if you paid more for higher octane non-ehtanol fuel. (10% usualy is at 89 octane and sold as 87/89 as the same price). It has less hydrogen in it and more oxygen so your car reads it as leaner and adds more fuel, thus less gas mileage.

EDIT: just saw twentysixtwo mentioned MPG as well...

Interesting - thanks. It does not sound all that great once you consider the cost/MPG issues, doesn't?

Will

wquiles said:

Interesting - thanks. It does not sound all that great once you consider the cost/MPG issues, doesn't?

Will

Click to expand...

Actually it does, if you look towards the future (don't know how far) when for political, economic or other reasons the oil supply is unavailable. If that time comes, it will be nice to find that we have an alternative available.

After an embargo starts is NOT a good time to start research.

Daniel

I have a 2000 Ford Ranger FFV, Flexible Fuel Vehicle.
It runs on good ole regular or E85.
I have read that a few states sell this very very cheap!
Your MPG'S go down a bit.
However, I found ONE E85 dealer in Ohio...wanted 2.79 a gallon!
Supply and demand....

Exactly. The demand went up here and they raised the price to where you actually loose money if you use it. But most people don't know that. I notice a big mileage change just when using 10% ehtanol. The gauge will go down durring a days worth of running around. But pure gas, it seems like the needle won't move even if you floor it all the time! hehe. Soon though due to politics they will require all gas here to have 10% and the last station that doesn't have it will be forced to sell it. It's to help the farmers crop sales.

There are 3 big advantages of ethanol as a fuel:

1. The dollars stay local

We import over $300 billion/yr of petroleum. If that money stayed here, it is the equivalent of 3 million new jobs worth $100,000/yr in salary and benefits. Since money that circulates creates even more jobs, it is really like 4.5 million new jobs...just from switching to U.S. produced fuels.

2. CO2 build up

Not everyone believes in global climate change (sometimes misnamed global warming). 60 minutes ran a segment on it last Sunday night that was pretty sobering. Renewable fuels like ethanol recycle CO2 instead of taking CO2 out of the ground and putting it in our air. The levels of CO2 we have now are higher than at any time in the last 650,000 years.

3. Fuel interuptions

Ethanol that we make here, can't be interupted by hurricanes, wars, terrorists, hostile foreign governments, etc. Since it isn't shipped here in super tankers, you don't have to worry about oil spills either.

Finally, since ethanol is naturally like 100 octane, if we had high compression engines that used the full octane rating, we could recover some of the mileage that you lose to the lower energy density. Although, you've got to have wide distribution before you can take advantage of that feature. Until then, we need Flex Fuel cars that can run on either gasoline or ethanol. My web site has discussion of this.

www.itsgood4.us

to take the thread a bit off topic, I think that Ikendu's comments apply to any fuel made from organic material, whether it's ethanol made from corn or switchgrass, or biodiesel made from soybeans. It makes a lot of sense to just recycle the carbon that's already on the planet's surface, instead of digging a bunch out of the ground, and then having that carbon stuck up here and producing greenhouse gases.

Boy... I am vaguely encouraged by Pres. Bush's odd advocacy of domestic energy production! I can just imagine the midwest USA being not only a producer of food, but of fuel/energy. With all the beans and corn that we grow, plus the potential for wind energy, we would do quite well! Of course, Bush seems to be focused more on nuke energy... and the nuke plants here in Illinois have had some problems recently with releasing radioactive stuff.

but... back to topic : I'm glad to hear Bush talking about plug-in hybrids powered with ethanol, etc. Certainly a path towards oil independance, plus a chance to advance domestic technology and manufacturers! Can you get an E85 Prius right now??

Steve K.

Last I heard the Prius does not do well on E85. It dislikes premium too. The car is tuned for 87 octane regular.

Since the Prius starts and stops the engine hundereds of times a day, it needs to be able to start dependably. The prius was designed to be CLEAN and not thrifty. The fuel economy is a byproduct of the design. A start cycle that does not catch on the first power stroke puts unburned gas in the exhaust. The use of E-85 could, in some conditions, cause more pollution per mile. That would be bad.

The Prius has various detectors and sensors to make sure it's running cleanly. A misfire on one cyclinder, for instance, will throw a trouble code. I hear that using premium gas will also (sometimes) throw a code.

Daniel

I'm not going to get too excited about the government "initiatives". There are hundreds of things that could be done NOW with minor incentives. We don't need massive changes if we won't even require better energy efficiency from existing products. We've wasted billions on "hydrogen powered" research.

There's a saying in the "off grid power" community. It's easier to save a watt than it is to generate one. It's more economical too. IN essense we could halve our future motor fuel consumtion by simply requiring an appropriate CAFE level. Make 45 mpg the AVERAGE for a manufacturer's models and you will see some really neat models emerge.


Daniel

Steve K said:

Can you get an E85 Prius right now??

Steve K.

Click to expand...

No, but Ford announced that the Hybrid Escape will be available in E85 Flex Fuel in 2 years? (I think).

As far as stopping and starting, the hot setup (IMHO) is the Plug-in Hybrid Electric Vehicle (PHEV). The PHEV has significant all electric range (at least 20 miles) and only starts the engine when the batteries are depleted and need recharge. If your trip is 20 miles or less, you just plug in and recharge off the grid. Electricity is estimated to cost only a third of the cost of gasoline for that 20 mile trip. Making a diesel (biodiesel) or E85 car of this type should be pretty efficient. You'd just run the engine at a constant, highly efficient speed until the batteries are recharged (no stopping and starting). Emissions should be really low too... all steady state operation. You don't even need to worry about sudden needs for acceleration or sudden torque needs... you just run at steady state with the engine/generator sized to produce enough electricity to keep the whole thing moving plus some recharge.

OK guys I have started making my own ethanol, Planting the crops this spring. Sweet Sorghum (multi color). I thought about corn , but that takes an extra step of changing starch to sugar, then sugar to alcohol.

Thought I had it all set up with the Smartplug people, but I dont really think they have a working model, Smartplugs where suppost to take the place of a regular spark plug, and burn just about any type of fuel. Even 50/50 gas/water.

Now after reading in your posts ( thanks by the way because i think you saved me a on of $$$$) that the ethanol is corrosive, RATS.

If they have been making VFV since the 1990, how would we know if we have a VFV that can take ethanol? cant take the manufacture word for it, so how could we check this ourselves???

thank guys
Great forum

The downside that I see is the reduction in mileage. Figure about a 25-33% reduction in fuel mileage with E85.

Doesnt sound good to me.