Ok, as promised, here's the article I wrote for Drag News in 06.
Part 1“Moonshine” Racing
By Mike Tritle
Looking out a motel window at the corner gas station only to see a higher price every 20 minutes can be quite unnerving for a traveling rep 300 miles from home driving a 12 mile per gallon 4x4 pickup truck. As Katrina remnants passed through Indiana that day, regular unleaded gasoline prices skyrocketed from $2.89 per gallon to $3.59 in just over an hour. Thoughts of the higher cost of my trip to low car counts at events to what would happen to the price of race gas went through the heads of more than a few sportsman competitors during the weeks ahead as evidenced by then very active bandwidth overloaded message boards across the internet. For this racer/sales rep/would be writer, it spawned an idea not only for day to day consumption but for our favorite pastime as well.
For more than a few years some grades of gasoline have been mixed with ethanol, essentially “moonshine” only refined legally for use as motor fuel. When mixed 9 to 1 or 10%, fuel economy is virtually unaffected and in some cases power and mileage actually improve. Add to that the benefit of acting as a fuel system drier and cleaner, the added ethanol eliminates the need for other additives to perform similar functions. Octane is boosted as well which probably contributes to the increased performance of computer controlled fuel injected engines. A word of caution, however, using even 10% in an aged fuel system where it has not been used previously will scrub any varnish and scale out of the tank and into the fuel filter in just a few miles. Be prepared to change that filter soon after the first use of gasohol in an older vehicle!
More recently blends of up to 85% ethanol and 15% regular unleaded gasoline, or E85, have become available, especially in the Midwest agricultural states. Manufactures designated specially equipped models as Flex Fuel Vehicles and made them available in the late 90’s and early 21st century. These cars, vans and small trucks are calibrated and programmed to sense fuel type, or a mixture thereof and run equally well from pure gasoline to E85 blends with only a small drop in mileage as Ethanol content increases. Special components such as fuel tank, lines and injectors are included in the package to protect from potentially corrosive effects of certain alcohol properties.
So the big question is, at 105 octane, (as specified on the pump) why wouldn’t it work in racing engines, especially those built for pump gas as fuel? As prices rose outside the hotel, so did my curiosity as to how this readily available and comparatively lower cost fuel would work on the track.
It is commonly known that ethanol is produced from corn. What is not widely known is that any high starch vegetation can be used to produce high quality ethanol. I researched this through my son, Steve Tritle, Operations Manager for seed corn production at the Monsanto plant in Boone, IA. While corn is the preferred material, sugar beets, potatoes and even wet garbage will produce high quality ethanol for use as motor fuel. A frequent question is, “Are we able to produce enough crops to provide for the fuel thirst of the US without shorting the food supply?” The answer is yes as there are thousands of acres in the southeast sitting idle under government set aside programs that could be turned into fuel crop production within a couple of growing seasons. Government subsidies paid for non production could be redirected temporarily to benefit those farmers and producers to re-equip and build the plants needed for ethanol refining. All this benefits the US agricultural economy while reducing the country’s need for imported oil. This market force could further lower the price of gasoline as demand drops as well.
According to Mark Thomas, owner and driver of the Ohio Corn Growers sponsored Ethanol Performs IHRA Funny Car, Ethanol works quite well as a race fuel. Thomas has fueled his championship winning race car to ET and Speed Records and National Championships with “corn licker” flowing through its pumps and lines for several seasons now. When I asked him how it worked compared to the seemingly preferred but far more dangerous Methanol, he spoke freely of the mathematical formula used to compensate for the different characteristics of the otherwise related compounds.
It’s all in the chemistry. Taking a quick course in Fuel Injection 101 with Camp Stanley, 2005 NSCA Champion Pro Outlaw car owner, I learned that fuel mixture is calculated by comparing the area in square inches of the jets used in the inlet and return functions of the system used in Blown Alcohol Racing Engines. Applying this to a gasoline carburetor should yield similar results, I concluded, so I set about dredging up formulas unused since my classes at Lewis College School of Aviation in the early 70’s. I also searched the internet for comparison charts of fuel substance properties which was provided by one of the many of the Ethanol Industry’s websites. Specs are found at the two links here.
http://www.ethanol.org/pdfs/Fuels%20Chart%20pg%201.PDF http://www.ethanol.org/pdfs/Fuels%20Chart%20pg%202.PDF
Unlike Methanol the corrosive properties of Ethanol aren’t nearly as severe. To confirm this I soaked a piece of AQP hose, a viton needle and seat, an accelerator pump diaphragm and a power valve submerged in pure ethanol provided by Thomas for several weeks. There was no deterioration of any of the component parts. Ethanol seems to be no more corrosive than gasoline to the carburetor.
The major downside of Ethanol is, like Methanol, its affinity to absorb moisture. While this is a plus in keeping a daily driver’s fuel system dry, as a race fuel it must be properly handled to prevent water absorption. Unlike gas, alcohol absorbs humidity directly out of surrounding air into solution so it doesn’t settle to the bottom of the container, tank or cell. However, excess water results in a lean condition, inconsistency in performance and a potential for engine disaster.
The most important of these properties is the stoichiometric mixture ratios of Gasoline, Ethanol and Methanol which are 14.7, 9 and 7 to one respectively. Stoichiometric is the term for the exact amount of air to fuel required for complete combustion of the fuel and complete consumption of the oxygen within that air within the mixture. Of course if a race engine is run that lean it tends to perform an auto unscheduled disassembly so we run our engines in the neighborhood of 10 or 12 to one ratios with race gas. However, the stoich ratios provide a basis from which to calculate baseline jets sized for the ultimate mixture required for specific fuel.
Another critical factor to be dealt with is the heat required to evaporate each fuel. Gasoline will absorb only 700 BTU while ethanol sucks up 2140 BTU for gaseous state conversion. That’s why gas racers can ice down the intake manifold and make more power. Alcohol racers need hot engines and seldom use intercoolers as the fuel is its own mixture cooling agent. Engine temperature would be critical but just opposite of what was accustomed. (See Fig. 1.)
The Holley catalog provides jetting area numbers, though somewhat nominal. Several sizes are listed with the same numbers but close enough is the key word for establishing the base. Using the area of the current optimum jetting for gasoline will calculate up to the required base jetting for the alternative fuel. In this case, the target fuel being E85 also required factoring a different stoich ratio than pure ethanol. This is done by averaging the ratios of the two fuels. Multiplying 14.7 x 15% produces a factor of 2.205, and then 9 x 85% equals 7.65. Adding the two together sums up to 9.855 which was confirmed by another source indicating 10-1 was the nominal stoich for E85 fuel. Dividing 14.7 by 10 produces a factor of 1.47 which when applied to the base jet area would give the required upsize area for E85 jetting.
Here’s the really great part. Fuel for testing was purchased in Rockford, IL for $1.999 per gallon. The engine used approximately 20% more by volume per run over gasoline, then priced at 3.699 per gallon for Premium Unleaded. Factored cost calculates to 2.399 per gallon. As this is written, gasoline prices have dropped more rapidly than E85 but the cost savings is still substantial.
The test mule for this experiment was my 74 Plymouth Cuda. This one owner (me) car has been campaigned in NSCA/NMCA index footbrake competition since 2001 with a mild 360, built to run on 97 octane unleaded premium fuel. The low, 9.8-1 compression is slightly deficient for full utilization of the increased octane and the flat top piston design and stock heads already require 36 degrees of total ignition timing just off idle for optimum burn, less in certain weather conditions. Sealing is accomplished with Total Seal Gapless Top Rings and the engine has over 300 runs on it. A Holley HP 650 double pumper carburetor with 85 power valves, jetted 70 square and number 27 squirters off the 50 cc accelerator pumps feed through an Edelbrock Performer RPM Air Gap manifold to a mild lift and duration cam and 1 5/8” primary tube headers for the exit path from the port matched stock cylinder heads. Intake valves are 1.880 with exhaust measuring 1.600. With a 904 Torqueflite transmission and 3.55 gears the 3700 lb. car has run a best of 12.805 and 103.89 at 84 feet above sea level corrected altitude this season in Belle Rose, LA.
