Grendel writes: >You don't have to raise the compression to run ethanol but you can if you >want to. You can run a higher compression ratio using ethanol especially if >your engine has an aluminum head. > >What are the advantages for higher compression? simply more power or, as >someone stated, better mileage?
Higher compression gives you a greater expansion ratio which leads to greater efficiency of the combustion process. That was the purpose of lead in fuels was to allow greater compression which gave more performance for a given weight of engine and volume of fuel. >This is for a motorcycle, BTW. Any IC engine. The heat problems related to earlier are because of increased combustion chamber pressures and the greater power out. Aluminum heads help by conducting excess heat. Any IC engine. The heat problems related to earlier are because of increased combustion chamber pressures and the greater power out. Aluminum heads help by conducting excess heat. Alcohol has a higher knock resistance which allows greater compression ratios. If I remember correctly, it can take up to 14:1 before heating of the compressed FA mixture starts pre igniting. The greater fuel flow requirements of alcohol are because of its much lower Stoichimetric ratios. Pump gas is around 14.1:1 and alcohol is as low as 8.2:1. Again, I do not have my reference material here so the figures may be slightly off. This very low sotic ratio is one of the reasons alcohol is used in racing applications. The large flow of fuel helps cool things. Alcohol also expands quickly which in turn slightly cools the incoming FA mixture allowing a slightly heavier charge. The low stoic is the reason of the greater fuel consumption of alcohol over pump gas. The amount of energy power charge is the same but it takes significantly more volume of alcohol than gasoline. Some of that may be gained back by increased compression ratios. Biofuel at Journey to Forever: http://journeytoforever.org/biofuel.html Please do NOT send "unsubscribe" messages to the list address. To unsubscribe, send an email to: [EMAIL PROTECTED] Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
