E85 ethanol

8) since our engines are carbed, we can make a few mods to run E85 or straight alcohol. flex fuel is tougher though with carbs. if we set a carb up to run E85, then the engine runs too rich on gasoline. it can be done, but tuning is going to be somewhat of a nightmare. if you switch to EFI then making a flex fuel engine is much easier. you just need the right sensors, specifically the right O2 sensor, and programming. you also need injectors designed to run alcohol.
 
gasoline likes to be mixed 14.7 parts air to 1 part fuel

ethanol/E85 like to be mixed at 9 parts air to 1 part fuel

That's 1/3 more fuel needed when running E85. For a carburated car, this would require changing jets and power valves to maintain proper mix. Unless you want to swap parts eveytime you change fuels, its almost impossible to make a carbed engine 'flexfuel'.

Also, alcohol/ethanol attacks some materials used in the fuel sustems of gasoline engines, like rubber hoses and o-rings. They need to be changed to materials like nylon and Nitrile.

Now, a fuel injected engine is a different story. To change a/f ratio, the PCM (powertrain control module) simply has to increase the amount of time the injector is turned on. FlexFuel vehicles utilize a sensor in the fuel rail that determines the amount of alcohol/ethanol in the fuel, and adjusts injector pulse width accordingly.

Aftermarket conversions for non-flexfuel injected vehicles are starting to come on the market, and some standalone PCMs offer the option of using a flex-sensor (www.megasquirt.info)
 
Making a carb work with E85 is easy, but like the others have said you can't just switch to normal gas whenever you want. It'll run on gas, but it'll be pig rich!
We've been running E85 in my wife's Falcon for a year or so now. The only complaint that we have is that it doesn't like to run very well when the carb is cold. And because of the alcohol content of E85, it takes a long time to get the carb up to temp.
Also we're running our car at around .82 Lambda. Which equates to about 10.5-11:1 A/F ratio on the normal gas scale. We have found that 9:1 is to rich for E85.

Also Kelly has commented that every once in awhile, her car smells like popcorn! :D
Later,
Will
 
I live an area where oxygenated/ethanolized gas is required in the winter and it's not any where near E85 and it sucks in my '83 F150 and in many of the older vehicles. My wife's 2004 Taurus is a flex fuel vehicle and runs fine on it.
 
Back
Top