When it came time to strap the Valiant to the dyno at Prism Racing, the guesses as to how much power the car would make were conservative. Let's face it, it's a small-block 340 with no special machine work done to it. We started with a conservative 5,500-rpm pass and noticed we had a small problem. As we mentioned in our opening paragraph, would you believe that 930 cfm of carburetion on our small-block wasn't enough? I didn't. With the relatively small cubes of our stroked 340 (414), I thought that 930 cfm would be plenty. When looking at the dyno chart, Darren noticed a sudden and severe drop off in power, and his experience suggested we needed more air flow. To get more air, we needed bigger carburetors-there goes this month's allowance. It was a toss-up as to whether or not a pair of 600-cfm carburetors would be enough, so the decision was made to get a pair of 650 Double-Pumpers and convert them to run E85.

Buying E85 dedicated carburetors is as easy as checking out any performance retailer online. Our problem, however, was that we were strapped to the dyno and needed them right now. We were fortunate in that we were able to locate a local retail warehouse that happened to have two 650 Holley Double Pumpers on the shelf and the required E85 conversion components.

After finally getting the carburetors switched over, we then ran into an issue where our engine developed a hiccup right around 5,300 rpm. This developed a situation that we weren't sure how to overcome. What it sounded like was something in the ignition. Instead of buying a new distributor and hoping it solved the problem, local Mopar guy, Ralph Vaquero came to the rescue with a factory distributor for us to try. After connecting Ralph's distributor, our hiccup went away.

After everything seemed to be happy with the Valiant, we proceeded to make 32 pulls on the dyno until we ended up making just 500 hp and 500 lb-ft of torque. There was definitely a lot of jet changes and tuning going on-as with any dyno session. We finally ended up with 40 degrees of timing and jet sizes about 8 sizes larger than were needed with race fuel.

Things To Remember When Considering The Use of E-85
Ethanol contains less BTU energy than gasoline; therefore you need, depending on the application, about 10-20 percent more fuel as opposed to conventional fuel.

The Octane rating is generally around 105. This allows the use of higher compression ratios.

E85 is still suffering from limited availability. Finding E85 depends a lot on your location, as most of the E85 pumps we've heard of are located in the mid-West.

E85 can be more corrosive on some rubbers, plastics, and some metal parts because of its inherent properties. This means that you'll want to research your fuel system parts to ensure compatibility.

Emissions are greatly reduced when using E85. If you don't care about emissions, you should, but just know that what burns cleaner leaves your engine cleaner.

Not Always Equal
If you think that all E85 is the same, we're here to tell you that it's not. When dealing with "mass produced" E85, there are different "blends" depending on things like the time of year or just the primary mixing ingredients, and this can adversely affect peak performance-especially in areas prone to drastic weather changes. Currently, we have also found out that federally regulated E85 allows for a blending of anywhere from 70-85 percent Ethanol (ASTM D5798). While this might not have a huge effect on the normal daily driver, those who've done their best to optimize their engine combinations can really be in for a surprise from week to week, or month to month in regards to how their engine's performance is affected.