Shortly after the first installment of Circle Track's Project G.R.E.E.N. hit the newsstand it became apparent that the project had a multitude of different dimensions, all of which can positively impact the oval track racing marketplace. One of those dimensions that rose to the top very quickly was fuel and fuel choices-more specifically alternative fuels.
We have gotten a number of reader letters asking us to investigate ethanol vs. methanol vs. gas a little deeper than what was presented in the first article of Project G.R.E.E.N. Among the requests, these letters also demonstrated that there are a lot of misconceptions about how good, bad, or green these fuels may be in the context of racing applications.
Let's start with the magazine's fundamental motivation for going down this alternative fuels route. Today, the United States imports approximately 60 percent of all the oil it consumes. Using domestically produced ethanol will reduce our country's dependence on foreign oil. For a variety of political and non-political reasons, that is a good thing. In a nutshell, having a domestically produced, renewable source of fuel available for racers removes the power to control prices from those organizations outside our borders.
This chart shows the sources...
This chart shows the sources for various fuels. Note what can be produced from cellulosic biomass, a fancy term for yard waste.
In the development of Project G.R.E.E.N. the Circle Track team always knew we wanted to run the engine on an alternative fuel such as ethanol. However, as we delved deeper into the concept of ethanol as a race fuel our team began to realize that the tangible benefits of domestically produced ethanol make it the perfect race fuel. But before we get into the down and dirty of why ethanol is such a great candidate for a race fuel let's step back for a minute.
We have thrown the words "alternative fuel" around a lot in this project. Now simply put, an alternative fuel is any fuel that may be used that displaces the current use of liquid-petroleum-based energy sources. An alternative fuel may be natural gas, propane, ethanol, methanol, biodiesel, hydrogen, or even energy carriers, such as electricity. For the purpose of this article, we will focus on ethanol, or ethyl alcohol, with comparisons to race fuel and methanol, a fuel that has been commonly used in circle track racing for years.
Ethanol-A Chemistry Lesson
In the United States, ethanol (EtOH) is traditionally obtained from corn because it's a low-cost source of sugar. That sugar can be converted to ethanol at the large volumes needed for commercial fuel. The chemical composition of ethanol is C2H5OH and is no different from the alcohol one drinks in a cocktail during a happy hour at the local watering hole. In comparison, methanol (CH3OH) is toxic to humans, and consuming as little as 10 ml can cause blindness-consuming 100 ml can cause death.
Today, soybeans and even the...
Today, soybeans and even the post-harvest plant matter not used can be a source of ethanol, an alcohol that some racers are currently running on today. Courtesy Of Argonne National Laboratory
Now, to sell ethanol as a fuel, it must be denatured so that it is not consumable. Denaturing of EtOH is typically done by blending it with a small portion of gasoline. E85 is actually just a blend of approximately 85 percent denatured ethanol and 15 percent gasoline. The gasoline is added to improve cold starting, which can be difficult with ethanol that reaches near 100 percent pure levels; it also adds to the energy density of the blend. If you see E10 on a fuel pump, you've most likely guessed it: approximately 10 percent is ethanol, and the remaining 90 percent is gasoline.
The benefits of ethanol relative to race fuel and/or methanol are multifold, but let's start with the one many of you already have guessed-power. A typical (R+M)/2 octane rating of E85 is around 100. The naturally high octane allows for greater compression and expansion ratios-the power and efficiency benefits to the racer of higher octane are well known and widely published.
Second, ethanol has a higher heat of vaporization relative to gasoline-a significantly higher value. A typical heat of vaporization for gasoline may be on the order of 59 kilojoules per kilogram of fuel. For ethanol, it's approximately 130 kilojoules per kilogram, which is more than twice that value for gasoline.
Volumetric efficiecy, as seen...
Volumetric efficiecy, as seen from this dramatic in-cylinder view of combustion, can be enhanced through the use of ethanol thanks to its higher heat of vaporization. Courtesy Of E3 Spark Plugs
Why is this important? Before a fuel combusts, it must exist as vapor mixed with air, using oxygen in the atmosphere as the source of its oxidant. Therefore, as liquid fuel is introduced into the manifold either by carburetion or fuel injection, it must first change from the liquid to vapor phase and sufficiently mix with the air before it will combust.
The energy required to vaporize the fuel comes mostly from the air, but a portion actually comes from engine intake surfaces as the fuel vapor contacts it. However, it is most ideal to use as much of the air for vaporization to maximize volumetric efficiency. If a fuel has a higher heat of vaporization, the intake air temperature will be reduced, resulting in better volumetric efficiencies as the inlet charge has a higher density. From this, one would expect significant gains in torque performance with ethanol relative to gasoline, and this will be shown to indeed be the case.
In published research work conducted by General Motors, full-load data of a four-cylinder, naturally aspirated spark-ignition direct-injection flex-fuel engine running on E85 demonstrated a near 15 percent increase in specific output relative to production gasoline counterparts, while showing an improvement in part load operation of 3-6 percent. These gains were associated with reduced heat rejection, increased volumetric efficiency, and increased dilution (EGR) tolerance.
As the Circle Track team publishes more of our testing results in the near future, we believe the readership will be pleasantly surprised with the power and torque results from a modern stock car engine using E85 as the fuel.
Beyond the power benefits that ethanol can provide there are two other big factors that make ethanol an attractive fuel for circle track applications. First, it's renewable; and second, it's clean-burning. In addition, since ethanol is less volatile than gasoline, there's a reduced chance of explosion in spills and accidents. And although ethanol is more corrosive than gasoline to certain materials, it is less toxic to the user.
This Brazilian-made van runs...
This Brazilian-made van runs on ethanol produced from that country's vast sugar cane plantations. Courtesy Of Argonne National Laboratory
The renewable factor is significant. In the United States, studies indicate that we could eventually displace about one-third of our imported oil through renewable fuels. Brazil-an excellent example of a country displacing imported oil with renewable biofuels-uses approximately 25 percent ethanol grown from its vast sugar cane resources in its fuel. Sugarcane, like all photosynthesizing plants, grows by ingesting atmospheric CO2 and, through a complex process, converts it into sugar and organic compounds (an organic compound is simply a molecule that contains carbon and hydrogen).
Engineers specializing in alternative fuels use the word "feedstock" to describe the raw material used to create ethanol. In effect, you can manufacture ethanol from anything green that has carbon and hydrogen as part of its chemical make-up. Consequently, there are several levels of feedstocks, first generation, second generation, and so on.
Brazil's sugarcane and the U.S.'s corn are two examples of first generation feedstocks used to generate ethanol. However, there are many second- and third-generation ethanol feedstocks available such as residuals from crop and forest harvests (corn husks, corn stalks, or sawdust), perennial grass, fast-growing trees, and, one day, even algae.
In other words, the leaves that fall from the trees in your yard can be collected and turned into ethanol. Not only that but advancements in what scientists call biomass catalytic, cellulosic, and even algae-based technologies are demonstrating that these sugar and organic compounds can be converted to ethanol fuel economically.
In addition to being renewable, the aforementioned second- and third-generation feedstocks come from atmospheric CO2 (that's carbon dioxide in the air we breathe); remember, these feedstocks are essentially plant leftovers that have already taken part in photosynthesis when they were living and have converted atmospheric CO2 to the all-important oxygen. A second-generation feedstock's contribution as the base for a renewable fuel significantly reduces the well-to-wheels global-warming gas.
Well-to-wheels is another term that gets bantered around the green racing world quite a bit. As its name implies, it's an analysis of the amount and type of energy (including emissions) used from the time you harvest the fuel from its source (well) to the time it is completely spent in your vehicle (wheels).
October 2009 Overall Average...
October 2009 Overall Average Fuel Prices on Energy-Equivalent Basis; Nationwide Average Price in Gasoline-Gallon Equivalents.
Now, if you analyze the amount of CO2 emitted from burning a renewable fuel relative to the amount of CO2 generated in processing and delivering that fuel to your gas tank, the recycling of CO2 in growing the fuel feedstock "upstream" of its production greatly offsets the emissions from the tailpipe. Actually, cellulosic E85 could potentially reduce CO2 well-to-wheel emissions by about 65 percent.
In the case of E100, that reduction is about 90 percent. On the flip side, when one burns petroleum, CO2 is being released into the atmosphere that was stored in oil reserves that took millennia to form, adding to the overall CO2 content in the atmosphere. When one burns cellulosic E100, any residual CO2 released by the burn is only replacing CO2 that was previously consumed by the plant before it became feedstock.
Methanol-Not Really Green
Concerning methanol, it's commonly made by converting natural gas through a high-pressure catalytic process in the presence of steam. This process is referred to as steam-methane reforming. Because natural gas isn't a renewable source, the carbon footprint is higher relative to ethanol. To conclude, in theory, if a country were to be able to produce ethanol in quantities sufficient for personal transportation needs, they could produce an endless source of energy that largely circumvents the global climate change debate.
To summarize the pros of ethanol with regards to energy security:
• More power: The higher octane rating relative to gasoline delivers more power; in addition, the higher heat of vaporization results in better volumetric efficiencies
• Significant well-to-wheels greenhouse gas reduction: Using ethanol greatly reduces the contribution of gases associated with global warming.
• Renewable: Ethanol is plant/algae/energy crop based and therefore can be regrown.
• Supports domestic markets and agriculture: If produced domestically, money that is normally exported to pay for oil stays local (today, nearly 60 percent of oil that the United States consumes is imported).
Now, we need to cover some of the drawbacks and issues associated with using ethanol, and yet demonstrate that they may be outweighed by the benefits.
One drawback associated with ethanol usage relative to petroleum-based fuel is the inherent lower energy content. E100 has a lower heating value (LHV) of approximately 26.9 mega joules per kilogram (MJ/kg) of fuel combusted, whereas gasoline has a LHV of 44.0 MJ/kg. Simply stated, this means that a gallon of ethanol has only 61 percent of the energy of a gallon of gasoline. The 15 percent of gasoline in E85 raises the energy content of the fuel to about 70 percent of that in gasoline.
Compared to ethanol, methanol has an even lower heating value of 20.0 MJ/kg. In other words, a gallon of ethanol has only two-thirds the energy of a gallon of gas, whereas methanol has less than half.
Real-world use of E85 relative to gasoline, however, shows an approximate reduction in mileage of only 25 percent, not the 33 percent expected from the energy content deficit. The reason for this lower percentage is that 15 percent of the energy in E85 is gasoline, in addition to a few other favorable characteristics of ethanol fuel that will be discussed in further detail.
The reason for the lower energy content is quite simple once one looks at the chemical composition of the fuels and compares the theoretical stoichiometric combustion relative to gasoline. For those unfamiliar with the term, stoichiometry refers to the balanced chemical reaction of a substance with another-in this case, combustion (which is an oxidation exothermic reaction). If we use some representative composition of C8H16 for gasoline, the equations in red above represent full combustion of ethanol vs. gasoline.
Nitrogen accounts for approximately...
Nitrogen accounts for approximately 79 percent of the atmosphere. For the most part, nitrogen passes through without reacting, other than small amounts that form NOx emissions. For the sake of simplicity, we do not consider this here.
Although the study of combustion and reaction kinetics is extremely complex (requiring a book unto itself), a few interesting tidbits can be derived from looking at these stoichiometric equations.
First, both methanol and ethanol contain an oxygen atom. Since one of the critical energy-releasing reactions (exothermic reaction) in hydrocarbon combustion is the carbon monoxide oxidation process, the reduced C/H (carbon/hydrogen) ratio in ethanol and methanol results in less energy per molecule relative to the gasoline counterpart.
Second, the ratio of water formed, relative to the number of C/H bonds, is less favorable for the alcohols. Since water exists in the exhaust as a vapor, the heat of condensation can't be extracted as the piston expands and is wasted (this is the difference between lower and higher heating values). Simply, 100 percent combustion of ethanol can't make up the energy deficit relative to a higher saturated carbon-based petroleum-fuel counterpart, so a larger volume of fuel needs to be consumed to get the same amount of work out of an engine. This needs to be taken into consideration for fuel cell sizing, as well as cost, which will be considered here.
The current cost of E85 on a gallon-equivalent basis is lower than gasoline. However, comparing ethanol on a gasoline-equivalent energy basis (how much energy one can extract from a fixed quantity), the costs are slightly higher, as illustrated in Table 1 on the previous page. (Note: The cost comparison against gasoline in this table is relative to pump gas, and not 100-octane race fuel, which is vastly more expensive.)
Is it really green? Another issue associated with ethanol use is the perception that the fuel displaces food stocks and uses large amounts of fertile land and water sources to grow. This issue depends on the source of the feedstock. A study conducted by the U.S. Department of Energy found that more than 1 billion dry tons of naturally occurring biomass (dead leaves, grass clippings, farm plant waste, and so on) could be sustainably harvested from fields and forests and would sufficiently displace 30 percent of the nation's annual petroleum needs for transportation fuels. Using this source for fuel, such volumes would sufficiently cover all of racing and simultaneously avoid issues associated with food or water for fuel debates.
The final issue discussed here concerning alcohol fuels is corrosiveness to certain non-synthetic and natural rubber materials, as well as non-treated aluminum. For ethanol, the corrosion can come from reactions with the rubber-based material, ethanol's hydrophilic nature with water (and if water is present in the fuel, it can rust certain components), or sometimes galvanic reactions.
However, synthetic materials are now used to replace rubber components that are reactive with ethanol, and fuel system parts can either be substituted with materials less prone to corrosion or coated (i.e., anodized), which eliminate the issue. Ethanol is, however, less corrosive than its cousin methanol.
For methanol, the following reaction occurs in the presence of aluminum:
6 CH3OH + Al2O3 => 2 Al(OCH3)3 + 3 H2O
This reaction represents methanol's corrosive nature with aluminum oxide; the surface coatings normally used in racing to protect the aluminum from direct contact with the fuel, keep it from oxidizing and corroding. In addition, there are safety issues with methanol that need to be addressed.
First, it is nearly colorless when combusting. This greatly reduces the realization of fires, which can cause obvious safety issues. Also, methanol exhibits much higher levels of toxicity in humans. Methanol is toxic to humans in low concentrations and is readily absorbed through the skin, so extra care needs to be taken in handling.
Minnesota Late Model racer...
Minnesota Late Model racer Dustin Reeh switched from methanol to E85 and reduced his weekly fuel cost by more than 50 percent. Courtesy of Dustin Reeh
These issues, however, are well known and documented, and OEM engineers have successfully addressed them for ethanol through the development of low-cost, production-ready flex-fuel vehicles that can handle high concentrations of ethanol fuel. Since methanol is toxic and corrosive and has significantly reduced volumetric energy content, methanol is not recommended for use in production flexible-fuel vehicles.
To summarize the cons of ethanol usage:
• Corrosive: Ethanol can be hard on non-synthetic and natural rubber fuel system parts. Engineered solutions are widely available to address this issue.
• Land/labor viability: Considerable land is required to grow the crops, and labor for growing and transporting the crops is required. By using the proper ethanol feedstock, this issue may readily be addressed.
• Lower energy content than gasoline: The inherent lower volumetric energy content discussed with E85 relative to gasoline results in decreased mileage. Methanol is far worse because of its lower energy content. However, power potential versus gasoline is increased in both cases.
The Bottom Line
To reduce our reliance on foreign oil, renewable fuels will play an increasingly vital role in the future. This country has a long history of ethanol development, and recent technologies-such as cellulosic, catalytic biomass conversion, or perhaps even algae-based methods-will result in the production of a fuel that sidesteps food crops and concerns about global climate change. Most importantly, renewable fuels are expected to be sustainable energy sources that simultaneously create domestic jobs and boost economic growth as they prevent money from leaking out of our country to pay for foreign oil at home, thereby building our economy.
The properties of ethanol make it an ideal substitute relative to racing fuel: lower volatility and levels of toxicity, high natural octane, high heats of vaporization, and higher overall efficiency. But don't take our word for it.
Take the example of Dustin Reeh, the 33-year-old WISSOTA Late Model racer from Rochester, Minnesota. "We ran methanol in 2007 and 2008. Then at the beginning of last year I bought an E85 carburetor from Quick Fuel," says Reeh. "It cost about $800, but I had a $400 fuel savings (by switching to E85). Now that's based off of 18 to 20 races per year, but I have a $400 a year fuel savings, so in two years I paid for that carburetor." That's not all either. "On top of that, I'm paying $2.30 per gallon versus Methanol at $4.50, and racing gas, depending on where you're at, is 6 to 8 bucks a gallon."
While saving money was part of Reeh's motivation there was another aspect as well. "The methanol carburetor that I had was about 5 years old-I bought it used and needed to upgrade it anyway. During the 2008 season, I bought a Race Pumps fuel pump, which as you know, is good for anything from gas to alcohol; so basically I already had the setup. I had the fuel pump. I had the regulator. Switching from alcohol to E85 wasn't a huge change-there was some stuff I changed but the biggest motivator was I had to change the carburetor anyways."
Another plus was that one of Reeh's main sponsors is a farmer. "I have one sponsor and they're farmers. It's a big plus to them because we're using their stuff to go racing."
Saving money, fuel flexibility, and keeping your sponsors happy is great, but does the stuff work?
"To tell you the truth, it's very compatible with the alcohol. With the WISSOTA Late Models, you're allowed to run gas, ethanol, or methanol. I haven't had it on the dyno so I don't have exact numbers for you, but power-wise it's every bit as good as the methanol."
In the course of the switch, Reeh did upgrade his cylinder heads and went to a triple pass radiator. But there was one issue. "There's not a lot of information out there about racing with E85. So, it was a lot of trial and error at the get go.
While yet to see a dyno, this...
While yet to see a dyno, this E85 motor's performance is comparable to the driver's former methanol powerplant. Courtesy of Dustin Reeh
For example, I'm getting my ethanol straight out of the pump. Well, in the wintertime they lower the percentage of ethanol and in the summer they raise it. I got a gauge from Quick Fuel that tells you the percentage of ethanol in the fuel. Well, once we started checking different stations we found ranges from 83 percent all the way to 90 percent ethanol.
"Once I found a consistent supply, I tuned it in with jets. It probably took about four or five races then we were right back in the swing of things. My finishes show better in 2009 than they did in 2008, so I'm super tickled with the whole thing."
Another plus to changing to E85 from methanol is that E85 is less maintenance. Methanol racers will typically drain the fuel bowls in the carburetor after every race and then fill them with gas so the motor is ready to fire again. As mentioned earlier, methanol is really corrosive and hard on parts. Whereas the 15 percent of gasoline found in E85 keeps the corrosion to a minimum, and it's far lower maintenance than compared to methanol. Reeh found just a little bit of white corrosion in the fuel bowls from the E85 at the end of his '09 season which consisted of almost 20 races.
But the real advantage to E85 is the weekly cost. "The station we get our ethanol from is right on the way to the track," says Reeh. "Each week it costs about 20 bucks to fuel the car up. Before that we were spending anywhere from 45 to 50 bucks a week on methanol."
Although the energy deficit of the fuel can't be fully overcome, current costs of ethanol relative to race fuel are lower and would result in a net decrease in the cost to the user. Corrosive issues associated with ethanol are well known, and the parts are already available to remove this concern at a low cost.
Compared to methanol, ethanol is nontoxic, less corrosive, has higher energy densities, and is already available in large volumes, reducing the vulnerability of racers to oil price increases and supply disruptions. All of these benefits add up to a fuel that could hold much promise for the future of racing, and greater sustainable energy independence as well. Think of it this way, if you cut your fuel consumption by more than 50 percent like Dustin Reeh you can race more than 50 percent more.
We thought you'd be interested in the vitals on Dustin's motor and just what goes into racing a "green" Dirt Late Model. This is a wet-sump engine with an 8-quart oil pan, although Dustin says he may add an Accusump this year. You might be surprised at what little difference there is in his engine compared to a straight gas motor.
• 358ci. small-block Chevy
• GM forged steel crankshaft
• 5.7 eagle rods
• TRW 12.5:1 forged pistons
• Reed roller camshaft
• Crower roller lifters
• Brodix SPCH WISSOTA-spec cylinder heads, 2.08 intake valves,1.6 exhaust valves
• Brodix HV 1000 intake manifold
• Race Pumps fuel pump and regulator
• Quick Fuel Technologies 750cfm E85 carburetor, 92 jets (baseline)
• Performance Distributors D.U.I. HEI distributor
• Scott plug wires
• Schoenfeld 1 3/4 to 1 7/8 headers
• AMSOIL 15W-50 synethetic oil