Using E85 Pump Gas

A tiny blower, off-the-shelf aluminum heads, and a small green carburetor running E85 fuel is enough to make scads of torque and horsepower.

Two of our most successful dyno tests last year involved the Magnuson-supercharged, Vortec-headed, 350ci small-block Chevy that appeared in the Sept. '06 issue ("Big Power From a Little Blower") and the Nov. '06 issue ("The E85 Solution," the story on dyno testing a 12.5:1 compression small-block Chevy on E85 ethanol-gasoline blended fuel). Like some of the best duos in history-Batman and Robin, Abbott and Costello, Rogers and Hammerstein-we decided that partnering that 105-octane ethanol fuel with a blower would be a very successful merger.

Here's why this works. As you may remember from our first E85 story, ethanol offers up roughly 30 percent less Btu heat-output per pound of fuel compared with gasoline. That means to make the same power, we have to use 30 percent more fuel. This requires basically a methanol-style carburetor (or 30 percent larger fuel injectors with EFI) to make up the difference in fuel flow. While this may not sound good on the surface, keep in mind we're talking about a 105-octane fuel (R+M/2). Plus, E85 sells around the country at roughly $2.80-$3.00 a gallon, which is far cheaper than race gasoline at the same octane rating. True, E85 is not available everywhere, so the difficulty will be for those of us in states where E85 is not yet available, which includes California. For you Midwest horsepower junkies, E85 should not be hard to find. For the rest of the nation, be patient. E85 is coming to a gas pump near you soon. If you can't wait on this idea, a good substitution that would not require a custom carburetor would be 100-octane (or higher) race gasoline.

Our plan was to upgrade our little cast-piston small-block Chevy to forged pistons and retain the same Crane cam, Vortec heads, and Magnuson blower from the last test. This time, the higher-octane fuel would allow us to add more ignition timing that we couldn't run last time for fear of falling victim to the destructive forces of the evil Dr. Detonation (who lives in a jar in the kids' room and escapes on a regular basis). But, just like any good performance test, we discovered a hidden limitation: Vortec-head rocker studs. That turned out to be a blessing, since it gave us the excuse to flog a set of TFS 215cc aluminum heads to make even more power-to the tune of 601 hp and 631 lb-ft of torque. This baby rocks.

Crane Powermax 288 Cam Specs

*Stock lift at 1.5:1 rocker ratio is 0.458/0.473 inch. The above lift numbers are the result of using Crane's Gold Race 1.6:1 roller rockers on the aluminum heads.