Thread: 110 octane gas vs. alcohol....

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I'm building a 421 c.i. sbc, sparing no expense to acheive 700+ h.p. I am not familiar with all the different types of alcohol fuel available, so naturally, my choice is to use racing gas. I have been told by several racers, to go the alcohol route....they say it will increase h.p. by at least 10% over gas. My concern is....doesn't alcohol really shorten the life of your engine? Also....if I go with alcohol, is jetting the only thing I need to change in my carbs? Thanks. Dave.

No, jetting is not the only thing.... If you're sparing no expense and want to run alcohol, then buy a carb made for alcohol.... There are a lot of mods on the circuits in the carb, too.... AED, Quick Fuel, Barry Grant are just a few of the companies that sell them.... We run on E-90 using a carb build by Vindicator....works great and has for about 3 years now.

Thanks for the input. It seems that E-85 is the common product that I have heard about, and is fairly available in this area. Are you familiar with it? I'm assuming the E-90, which you are using, is similar, but maybe more potent?

yeah, we blend our E-90, start with some E-85 from the pump, then add some 100% ethenol to bring the mixture to E-90. Increases the octane to 109 and gives us a bit of cushion on the compression.... As I said, we've been using it for 3 years now and absolutely no problems, combustion chambers look great, burn pattern on the piston top is great. We did a bit of playing getting the right plug in it, and getting the plugs indexed but no problems since. For whatever reason, the car is a whole lot more consistent during the course of a day then it ever was on gas....seems to be less effected by heat and atmospheric changes....

Plain old E-85 comes out at about 105 octane, so you can run some decent compression.... Ours is a big block Ford, but the same princples will aplly to a sbc....

Thanks again....I'm going to give it a shot. I have an opportunity to get a nice tunnel ram with a pair of Holley carbs, already set up for alcohol. You convinced me.

I will caution you that plug reading with Ethanol or Methanol is more difficult because it does burn so clean on the plugs.... We finally bought an air fuel monitor.... We also do our "spring tune-up" on a chassis dyno that has a mixture analyzer...after a couple pulls, we know where we're at on the jetting, plugs, timing, etc.....

Some say it's a lot of hassle to go through, but IMO the difference in price from our E-90 to race gas with a comparable octane more then justifies it!!!!