Firstly, I will try to respond to questions and comments about ethanol / my KR build as soon as I can. The upcoming events and work load my company is seeing may take up a large portion of my "free" time. Thank y'all for being patient.
Something I might need to add: I noticed someone mention corn and ethanol. Which yes, it is a not so economical plant to obtain ethanol from. You can use any vegetation that has sugar or starches in it. The most economical being sugar cane. There is a commune in Brazil that runs a sugar cane/ ethanol plant. They are able to use the biproducts of making sugar and ethanol to fertilize their fields and fuel their boilers. which reduces production cost. bjoenunley - The only issue we had with cold weather was on start up of a cold engine. Once started we did not notice any unaccounted for difference throughout density altitudes and air temperatures, that you wouldn't already be accounting for with 100LL. laser147 - Your cadillac was most likely tuned and built to run on 87 octane from the pump. Horrible mileage on ethanol is something that was expected when the auto industry started building "flex fuel". If the engine is built and tuned to run souly on ethanol fuels, they will run below performance on mogas. (think of trying to put regular fuel from the pump in a tuned up race car engine, it will run rough with low performance). Bill Jacobs - Thank you, I know there are different opinions. It is nice to discuss those opinions and difference in research and experience. Many of the airshows we would fly to or in would be full of people bad mouthing ethanol and how horrible it is. Yet, very few would actually talk with us and "debate" the advantages and disadvantages of the fuel. Robert - When we did our C172, we sloshed an etching solution in the tank and then a sealing solution. I can not remember the exact solution we used, it did take a couple days to complete though. We did regular fuel test to on all our aircraft to check for alluminum in the fuel. We never had a positive result for alluminum particles in the fuel. As for preping the engines, if you don't increase the compression ratios then you won't take full advantage of the increase power with ethanol. So, we increased compression with different pistons, adjusted timing, bored out the injection ports (Dr. Shauck's secret as to how much), and ensured everything was compatible with ethanol. As for GPH changes, if the engine was tuned for 100LL we saw on average a 150% increase in fuel. Meaning that for every 1 gallon of 100LL we would burn 1.5 gal of ethanol. When we dyno tuned our IO-360 to ethanol, and ran 50 degrees lean of peak EGT (temps would drop on the lean side before reaching max EGT) we saw more of a 110% increase in fuel flow. GRG - Although ethanol does hold water, it can not/ will not absorb enough from the atmosphere to cause a problem with engine performance. This is based on our research with statics tanks at full and half tank. The test ran for 6 months of not touching the fuel tanks we had set out on the parking ramp next to our hangar. We then had our universities labratory (Gold standard) check for water content. We did however, intentionally add water to the fuel up to 25% water 75% E85. There was a noticeable increase in horsepower, accompanied by an increase in EGT. With that we started reaching max EGT on the IO-360 at 15% water, way more than static absorbtion. When I left the research program back in 2008 we had run two engines to TBO limits and had the wear measurements done as part of the research. There was less wear on some of the components, and normal wear on others. We equated this to the reduced vibration, temperatures, and extended oil life. We still maintained the 50 and 100 hour service schedules produced by the engine and aircraft manufacturers. We never had an issue with carbuerator icing on any of our aircraft. It could possibly be due to the alcohol having a much lower freezing point, and readily absorbing any moisture in the air. I do not recall any research into carb icing due to ethanol use, but it would be interesting to see the results of focused study. I do appreciate your input and experience with ethanol. Some of the disadvantages can be overcome with engine modifications, or a more agressive propeller to take advantage of the added torque and horsepower.
