Some of this info is from PM's, some of it I got from many places on the net, some of it is "copy and paiste", in some places I added more info in parenthesese (sp?), and some of it had to be retyped out. Any info I got I only got it from people that use or have used the fuel in the statement. Far too many people make quick judgements forming uneducated decisions. Whatever it's worth to whomever...
Alcohol, in the same exact engine with the same tune, will use 2X more fuel, and make a little less HP. (I found that most people said that alcohol makes a little less HP than gasoline while a few others said it makes a little bit more HP. I believe the variation in opinion is due to jetting and the gasoline they're comparing it to. I couldn't find a dyno that's been done on the comparison.) However, you can turn up the timing, and get the power back. Then you can run a more agressive timing curve, and make more power. Then you can add compression / boost and make lots more power. Alcohol has no lubricity, there are additives for that. The tuning window for alcohol is much bigger than gasoline. When alcohol is on fire there are no flames or smoke, there are additives for that. Alcohol is kind of like an acidic liquid in that it will "eat" or corode aluminum, pot metal, rubber, etc... Alcohol is easier to tune with over gasoline. Alcohol is also very corrosive, so you need to flush everything out before letting it sit. Alcohol - ratio is 6:1 instead of 12:1, so 2x the fuel. It keeps things nice and cool, great for those with a too small radiator and can't get enough cool air flowing. Somehow, not an issue with a boat. Great if your dynamic compression ratio is over 11.5:1. Downsides are, you will have to flush and WD40 EVERYTHING after you run it. I mean pull the plugs, drain the carbs, etc. Seriously. Alcohol burns much cooler than gasoline allowing much higher compression ratio's, much more ignition timing, much more boost on turbo and blower applications, etc... Reading plugs on alky is tricky. Bassicaly the plug should look new. Any color on porcelin is from additives or oil from motor. Intake guides, gasket leaking, rings etc. I always watch the electrode coming from the side of the plug, The "color" on this is an inducator of timing.
AvGas has no top end lube in it and there are additives for that. It is a general conscensus (sp?) from the people that play with their toys in the desert that once a engine has been run on AvGas for a while you can't switch it back to gasoline, it washes the rings out. I've talked with at least 5 people who've run AvGas in their jet boats, a few of them have run AvGas for over a decade with zero problems, and it has proven to be safe with engine with as much as 13.5:1 compression ratio's (use at your own risk). ... one of these builders while I was in the shop had a 468 on a stand with 14.5:1. That was the specific engine referenced when he was explaining the fuel thing to me. That motor was getting strapped to the dyno and was going to be running straight 100 octane AV. I'm curious how the dyno run turned out on that one too... He was telling me that in regular use this particular engine would run perfect with a 1.5:1 ratio of AV gas to premium, which is about 95 octane. It will sustain 12-1 compression no problem. I have run it in my dirt track cars and my drag car for years. I run it in my blower motor in my boat. It makes 13 lbs. boost and no intercooler.....no problem there either. It has lead in it...good for valves. Downside.... no upper cylinder lubrication. I fix that by mixing marvel mystery oil in it at a 100 to 1 ratio which actually raises the octane slightly also. Also another downside is it doesnt have as much explosive power ounce per ounce as compared to race gas.
2:1 will get you 97 octane
2.3:1 will get you 94
E85 acts like a combination of higher octane gasoline and alcohol. With E85 I've read that fuel consumption goes up 15 - 50% (I believe the variation is soley due to jetting and that 15% is a more viable comparison figure, read on). E85 is not nearly as corrosive as alcohol, the 15% mix with gas helps with that. E85 is Ethanol, not Methanol. Ethanol mixed with gasoline undergoes a chemical reaction when it sits too long in a tank, because it attracts more water, which leaves a non-combustable fluid on the bottom of your tank. 101 - 106 octane from the pump. Runs way cooler than gasoline. Has some of the charactoristics of alcohol but it's better than methanol, like not as dry on the upper side of the engine, not as corrosive on lines, tanks, etc. I went to GM school on the flexfuel vehicles, it does provide more power than super unleaded fuel. It also requires more of it to produce the correct air/fuel ratio, but we're olny talking jetting up a carb maybe 3-4 jet sizes to make the stuff work. E85 cleans all the old varnish and crap in the old tanks and lines. E85 will eat fiberglass too. May want to consider something to catch any sludge material, I guess a water/fuel seperator won't work, and also a
low fuel pressure kill switch. Those turbo guys are using aluminum gas tanks with no problems so the right fuel lines and a compatable pump should take care of fuel supply. Some guys say you need 10-15% more fuel and some all the way to 40% more. Most guys are using gas calibration and best power seems to be around 12.0 A/F ratio. Also need to drop sparkplugs down 3 sizes according to one of the manufacturers. It's not corrosive (as a lot of people claim that have never used it). I work on E85 vehicles everyday and they run great on the stuff! At the GM flex fuel classes I went too, they told us that GM vehicles used @20% more E85 than gas, but the 20% more also yielded lower egt's, lower intake temps, and @15% more power. E85 to top it off it is made 100% within the confines of the USA. Many people state that the fuel is corrosive and it could have adverse effects on aluminum fuel rails, injector o-rings and fuel lines, but so far in 9 months of testing we have seen no such side effects. E85 will give your tanks and fuel lines an "INSTANT CLEANING". For those of you who plan on running this stuff in your old varnished gas tanks, be carefull. The minute this fuel hits the system, it starts getting rid of all the gas tar that has built up over the years. I have been running it for a year in a weekend driver. The gas tank sat full of E85 all winter long. I haven't seen any indicators that this fuel is causing damage to anything. I had the gas tank out this spring and every thing looked fine. I haven't even needed to change the fuel filter. We ran E85 in a banshee, 72 hp on race fuel, 82 hp on E85. Just ran my first tank of E85 through. My fuel economy did not drop as much as the math suggests it should. I averaged 23 mpg on E85, and on the same trip I was averaging 26 mpg on 93 octane. So with my 50/50 hwy/cty commute it only dropped 10%. I love this stuff, I just hope materials compatability doesn't become a problem and force me to change anything. So far no problems though. That is half the loss the math shows it should be. I added more timing, but primarily just where is was knock limited. Car is much faster now. This is a daily driven car, about 330 miles per week. The loss should be close to 30%, but it is much less in my case. I am very happy with it as a fuel. I haven't even had to change my fuel filter yet (I fully expected it to clog in 500 miles). It smells NICE. E85 engine reacts more to even slight changes in a/f ration on E85 vs. gas, even at part throttle cruise. Cold start seems more crisp, and smells a little like coolant burning.
E85 To sum it all up
Why is Ethanol a better fuel?
1. It has a much higher evaporative cooling power than gasoline so the intake air charge in the cylinder is significantly cooler that it is with a comparable mixture of gasoline --- that means higher VE.
2. Its octane as blended in E85 is about 100, its blending octane when added to gasoline is rated at 118, so it is a very cost effective octane booster.
3. Ethanol burns faster than gasoline but has a slightly longer ignition delay during the slow burn phase of combustion so the engine does not do as much negative work fighting rising cylinder pressures due to large ignition advances. The total ignition advance for E85 is almost identical to the ideal advance for gasoline so it does not cause the PCM problems when you mix them.
4. At proper mixture you actually are releasing more energy in the cylinder due to the higher quantity of fuel you can burn. Ethanol can burn effeciently at much richer mixtures than gasoline can. That means about a 5% increase in energy release all by itself.
5. Peak combustion pressures are actually lower for ethanol than for gasoline but the cylinder pressures stay higher longer, so you have more "longer" crank angle that is usable by the engine. This lower peak cylinder pressure also helps with detonaton control.
6. Theorethically, the gain is 5% just by switching fuel. 350 hp X 5% = 15 hp, plus what can be gained from timing.
I just tried out E85 for myself. Its in a big ass cammed LS1 car, and the mph picked up from 89 to 92 in the 1/8. It didn't care too much as far as timing or richness. It seemed to like about 33 degrees advance, but would take up to 40 and ran the same (27 on 93 octane). It also didn't care too much about the AFR either. I varied it from 12.8 to 10.8 and it didn't pick up any or slow down. And my exhaust smells like rum now!!
E85, 1340 RWHP, Over a year in mine no issues at all.
• E85 is easy to use and handle - E85 fueling equipment is slightly different and of similar cost to equipment used to store and dispense petroleum fuels. In some cases, it may be possible to convert your existing petroleum equipment to handle E85.
• Using E85 reduces petroleum consumption - Use of E85 will reduce a fleet's overall use of petroleum and replace it with a renewable-based fuel produced ("grown") in the United States.
• E85 is good for the environment - Beyond operational ease, E85 offers considerable environmental benefits. To learn more about fuel economy, greenhouse gas scores, and air pollution scores for individual vehicles, go to the U.S. Department of Energy/U.S. Environmental Protection Agency's on-line Fuel Economy Guide. You can search for E85-fueled vehicles by selecting "flexible-fueled vehicles" in the "Select Vehicle Type" pull-down menu. Once you are there, select individual vehicles to get fuel economy, greenhouse gas, and air pollution details.
I did not do any researching on race gas.
