Completed and on the dyno, our Ed Taylor-built 355 ran flawlessly once we got past too-hot spark plugs that cost a warped valve.
Environmentalists and car crafters make strange, if not odd-opposite, bedfellows. The greenies are all over this not-so-new, environmentally friendly, renewable resource ethanol fuel that even has GM pushing it in its television ads. So what's all the fuss about and why should it interest you? Forget about greenhouse gases and that whole Al Gore political football. The real reason is simple: E85 fuel is a combination of 85 percent ethanol and 15 percent gasoline. Ethanol is an alcohol fuel made from the distillation of corn or other sugar-based carbohydrates, like beets or sugar cane. Straight ethanol has a race-gas-style octane rating of 115. Mixed with 15 percent 87-octane pump gas, E85 lowers this to between 103 and 105 and generally sells for less than 87-octane gasoline. You read that right. We're talking the equivalent of 105-octane race gas for the price of moose-piss pump gas.
There's much more to this story that you need to know, and the devil is most definitely in the details, so you've got to read this whole story to get the facts straight. Yes, you'll have to modify your carburetor to use it; yes, your mileage might suffer by as much as 20 percent; and yes, E85 is not available everywhere-yet. But we successfully tested this stuff in a 12.5:1 compression small-block Chevy against race fuel, and we not only made good power, but we also made a little more torque to boot. Now are you interested? And if you're already thinking this might make a great fuel for a supercharged or turbocharged engine-congratulations-you're thinking like a true car crafter.
What is Ethanol?
Think moonshine and you're on the right track. The stuff of Appalachian legend also makes an outstanding fuel. But don't confuse ethanol with methanol, which is a completely different fuel distilled from wood or coal. Ethanol is an oxygen-bearing fuel with a chemical makeup of C2H6O. That formula adds power by carrying its own oxygen (nitromethane is CH3NO2-lots 'o oxygen). By way of its three-carbon chemical construction and that single oxygen molecule, the Btu (British thermal unit) heat output of ethanol is not nearly as robust as that of gasoline. The numbers tell the story. One gallon of ethanol is worth 76,000 Btus, while gasoline is around 114,000 Btus. E85 is created by adding 15 percent gasoline to ethanol, which ups the heat count to roughly 83,000 Btus per gallon. By way of comparison, methanol generates a mere 56,800 Btus per gallon, or almost exactly half the Btus of gasoline. This means E85 creates roughly 27 percent less heat output per gallon than gasoline. This is partly why we must burn around 25 to 30 percent more E85 (at wide-open throttle) compared with gasoline to achieve similar results. Stamp this number on your forehead because this volume change is critically important when it comes time to modify the carburetor to flow more fuel.