All fuel burned in an internal combustion engine is burned as vapor - combustion of drops proceeds, first, by vaporization of the outer layer, then combustion of the vapor.
The only difference between vapor carburetion and the ordinary kind is WHERE vaporization takes place. Vapor carburetion actually reduces both the power of an engine and its efficiency. Power is reduced because of poor volumetric efficiency; fuel is being induced as a gas, and the volume of that gas displaces an equal volume of air, which could have been used to burn a greater mass of fueld. This is the reason that gasoline engines converted to propane have less power. Efficiency is reduced (and power further reduced) by losing the beneficial effect of vaporizing the fuel during the compression stroke (wet compression). That effect reduces the work of compression by absorbing some of the heat generated during rapid compression. When fuel comes in as a gas or vapor this effect is lost and the engine must furnish more compression work, reducing its net output. Vapor carburetion has a perennial appeal to people who don't understand thermodynamics and believe that inefficiency in internal combustion engines could only be due to incomplete combustion. It ain't so - look at the CO and UHC emissions of a modern engine and you will see that combustion is very, very complete. Improvement is still possible - even modern engines are functioning well below Carnot efficiency - but the improvement won't come by adapting the Coleman stove to automobiles. Marc de Piolenc Biofuel at Journey to Forever: http://journeytoforever.org/biofuel.html To unsubscribe, send an email to: [EMAIL PROTECTED] Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
