E85 = Rocket fuel for your hot rod!

A few months ago Car Craft magazine did an article on E85, in which I skimmed over, as I didn't think much of it at the time. Then in a more recent issue, they again used E85 in a blown small block. Again, I at first skimmed over it, until I ran across something that I had not realized, the octane of this new fuel was between 100-105 octane. More often than not the rating is closer to the 105 rating. I had recently pondered catering my big block chevy build up to utilize E85, though it was more along the lines to simply do something different, and to use a fuel that perhaps the cost would remain more stable than gasoline. When you have ride that gets under 10 mpg on the highway, $3+ a gallon for premium gets a bit costly for extended trips. Let's face it though, I'm not building an animal to be fuel efficient, but the advantages of running E85 ran much deeper.

After that article I went online to find additional information, as everything I had read so far seemed as if E85 could change the face of street machines forever. I knew the basics, that you'll need to use around 25-30% more fuel due to the lower btu's from E85, but I was more concerned about the octane advantage to be honest. If in fact the fuel was rated at 105 octane, and it's availability continues to grow as it appears it is, then this would allow much higher compression ratios. I have found anywhere from 13-15-1 cr can be had. In addition, it allows you to run much greater timing advance as well.

You pick up around 10-12 hp per 1 point gain in compression. So if I bumped my compression up from it's current 11-1 cr up to say 14-1, I'd see a gain of a good 30 hp, all while making the engine more efficient by making the combustion hotter thanks to the increased pressure. In addition, E85 being 85% alcohol, will also help to decrease the temperature of your intake charge. While I have yet to discover how much it would lower temperatures, every little bit helps, as it makes the air more dense.

The steps taken to convert to E85 are pretty straight forward on a carburated car. You need to make sure your rubber components are compatible, which most are considering ethonol is much less corrosive than methonol. Then you need to make sure you get your additional 30% of fuel needed, which involves fairly straight forward modifications to your carb. I may contact Demon carburation soon to find out whether or not they make metering blocks already modified for E85 so it would save me from modifying the once set up for gas. I assume they will be readily available, as most all carb companies have made conversions for methonol for many years.

While the current price of E85 is government subsidized by around 50 cents per gallon, at it's $1.85 a gallon current price, you can't beat the bang for the buck, as race fuel on par with it will run you $5-$6 a gallon. I'll continue to update my findings in the near future, as well as my decision to whether E85 is the path I will take. I need to remember to find out how it works with nitrous, as I plan on injecting a 250 hp shot into the mix.