Wayne Cook
September 14, 2007
Photos By: The Manufacturers, John Dickey
One of the earliest proponents of alcohol fuels was the old man himself, Henry Ford. He believed his Model T should be able to run on fuel produced by the farmer, so it's perhaps the first flexible fuel vehicle. Although the average farmer wouldn't have this model, here is a favorite Model T of ours-a Model T Speedster that shows up every year for the California Knott's Berry Farm show. Tank this thing up with white lightning and she'll do 80 with the right gearing and a tailwind.

E85 is an alternative vehicle fuel usually composed of 85 percent ethanol and 15 percent gasoline. Gasohol is also a gasoline and ethanol combination, but the ethanol content is much less, usually around 10 percent. Almost any vehicle should be able to operate on the gasohol mixture, while the "Flexible Fuel Vehicles" now on sale as new cars are designed to run on either gasoline, the gasohol mixture, or E85.

The ethanol contained in both gasohol and E85 is an alcohol that's produced by fermenting and then distilling a variety of plant materials. Crops that can be used include but aren't limited to corn, barley, sugar beets, and wheat. Wheat and corn are excellent sources for ethanol production, however, the high value of these crops as food means that other biomass sources will need to be found. At present, the technology for converting wild plants such as shrubs and grasses into ethanol is still emerging. Once this can be done cost effectively, there will be a greater potential for solving our energy problems rather than by distilling crop materials alone.

During ethanol production, the sugar content of the plant material is extracted and the sugar is used as food by microbes during the fermentation process. The end result, which is the same as bootleg whiskey or "white lightening," is alcohol and carbon dioxide. Using ethanol as a motor fuel has several advantages. Besides reducing the amount of petroleum used, ethanol is also good at increasing fuel octane and reducing undesirable emissions. The increase in fuel octane means a higher compression ratio can be used. Engines with cast-iron cylinder heads can easily go up to an 11:1 compression ratio, while aluminum headed engines can go even higher. Spilled ethanol is nontoxic and doesn't require cleanup of hazardous-waste.

Getting your vintage-Ford engine to run on corn is only a little more complicated than this. In fact, the whole plant, including the kernels, cob, leaves, and stem, can be used to produce high-octane fuel.

One of the disadvantages of using ethanol as a fuel is decreased range because a gallon of it contains less energy than a gallon of gasoline. About 60 percent more ethanol is burned per mile compared to gasoline. Another disadvantage is that the distillation process used to produce the alcohol also consumes a significant amount of energy as the mixture in the still must be heated. With E85 there are additional corrosion and water attraction factors to contend with.

AED Performance carburetion scientist Jay Brockwell and his team of E85 technicians were extremely helpful to us in writing this story. AED has examined E85 fuel use from every angle and says the corrosion problem "actually occurs more on initial usage as the E85 acts as a solvent that cleans out any built-up residue, rust, or other contaminates present in the fuel tank and lines." This dissolved sludge runs right through the fuel system directly to the carburetor. So before using E85, be sure to thoroughly clean the fuel tank, filter, and lines. Some E85 pro-viders may use tanks that held fuel oil previously or might contain some water, so try to buy fuel from a high-volume dealer that has a dedicated E85 storage tank.

The operating parameters of E85 require finer adjustments than those for gasoline, and it can be more difficult to tune E85 for acceptable torque, power, and driveability. AED used a computerized "wet flow-bench" to determine a linear fuel curve throughout the usable rpm range at wide-open throttle.

At present, there is no aftermarket kit that can be used to convert a classic Ford vehicle to run on alcohol fuel. However, several E85 capable carburetors have been recently introduced and would be suitable for classic-Ford conversion applications. Let's discuss some of the modifications needed for your car's fuel system to successfully run E85 fuel. We'll also look at the new E85-friendly carbs.

To run E85 fuel in an early car, the fuel system must not have any bare or unprotected aluminum, magnesium, or rubber components as the ethanol attacks them all. Ethanol conducts electricity whereas gasoline does not, so any electric fuel pumps used must be nonconductive where the fuel transfers through the pump. Likewise, any rubber diaphragm in a mechanical fuel pump could be subject to failure.

Here, Jay Brockwell of AED puts in the hours on the Superflow engine dynamometer. The flow bench tells only so much, and driveability matters such as throttle response and part throttle operation have to be sorted out on a real engine. Many hours of combined effort using both the flow bench and a real engine on the dyno got results.

Those using fuel injection need to adjust control systems. For example, filling the combustion chamber with the same explosive equivalent as gasoline requires a wider pulse width allowing for the injection of more fuel. Pro Max Carbs and Performance Parts of Indianapolis, Indiana, provided the table below, which shows the disparities in air-fuel ratios for four different types of automobile fuel.

When the required fuel flows were figured out for the 850-cfm test carb, the AED engineers went to their in-house Superflow 901 engine dyno. Initial tests showed the mixture running way too rich across the fuel curve. The big-block test engine sputtered and backfired, so they started going progressively leaner until operation smoothed out and the power came around.

If the carburetor is even a little too rich, the engine will miss. The tune-up must be targeted to a small operational window for good performance. Once satisfied with wide-open throttle performance, they moved on to general driveability issues such as idle, throttle tip-in, and cruise.

With gasoline, when the idle circuit is adjusted correctly-including the idle feed restriction and air bleed-then the transition circuit will usually follow suit and function properly. Not so with E85 fuel. A lot of experimentation with power-valve channel restrictors was required to completely solve all the driveability issues and get a good balance between part-throttle cruise and wide-open throttle. For E85, the stock transition circuit runs too rich, so adjustments to both the main jet and power-valve channels were necessary. To get all the circuits working together, extra restrictors were added for the carburetor main body to control the transition of fuel.

This is a billet metering block, where much of the E85 tuning adjustment takes place. The power valve resides in the center port, and the power-valve channels are on either side leading to the center. For home tuners or otherwise confident types, these metering blocks are available separately at AED and cost between $79.99 and $109.99.

In drag-race applications, some of the fine-tuning isn't as essential because part-throttle driveability isn't really a concern. Most of those interested in performance street use of E85 will be drawn to it because of the high octane rating. The higher-octane fuel supports higher compression, and higher compression means more power.

Street enthusiasts will definitely be interested in not just power but also driveability. Many people figure they can buy a set of metering blocks and convert their existing carburetor to E85 use, but it's not that simple. All of the factors we've looked at are integral to producing a reliable E85 carburetor. Remember also that instead of running a 14.7:1 air/fuel ratio for gasoline, we now need to run a 9.8:1 A/F ratio with E85.

As you can see, there's a fair amount of work involved in providing a smoothly functioning E85 carburetor. Just keep in mind that the engine will also need a fuel system that can support an additional 50-60 percent of volume of fuel to the carburetor.

Air/Fuel Ratios
 IdealRich LimitLean Limit

Air/fuel ratios for E85 show the biggest difference when compared to other fuels. Because E85 is so different from other fuels, careful attention must be paid to tuning the carb.

Looking For E85 In Your Area
Naturally enough, E85 is most common in the Midwest where much of the crops used for production are grown. In the Southeast and far West part of the country, E85 availability is spotty, but the situation should begin to improve rapidly. If you're not sure where to find E85 fuel where you live, go to www.e85refueling.com. Be sure to also check out www.e85fuel.com for more information about E85 fuels.

Now Available E85 Carburetors
Advanced Engine Design (AED)
AED says E85 could be a viable alternative to racing gas or even pump gas considering the pricing, power, and fuel properties. There is a torque and power advantage over conventional fuel when using E85. The higher octane rating will help those running high-compression engines to make big power and manage detonation problems. Compression ratios of 12:5.1 and more can be supported. AED now offers most of its carburetors in E85 Series configuration and says pricing will be similar to its alcohol models, which run from $629.95 for a 500-cfm model to $1,195.95 for the 1,050-cfm Pro Series Alky Dominator.

Advanced Engine Design
Dept. MF
2530 Willis Rd.
Richmond, VA 23237
(804) 271-9107

Edelbrock E85 600
In response to the growing interest in alternative fuels, Edelbrock now offers an Edelbrock carburetor for E85 fuel. The new Edelbrock E85 600-cfm carburetor is manufactured specifically for E85 fuel in order to take advantage of the 105-octane rating. In fact, testing proved that the new Edelbrock E85 carburetor improved performance over our standard carb with regular gas. The high octane rating of E85 makes it suitable for use in high-compression engines, resulting in more power while burning cleaner than gasoline alone. Featuring a hard-anodized gray finish with black powdercoated linkage, the new E85 carb includes a complete listing of all parts required for the conversion of the vehicle to E85 use.

Dept. MF
2700 California St.
Torrance, CA 90503
(310) 781-2222

Pro Max E85 M
Pro Max offers its new E85 carb for alternative fuel use. Available as a 750- or 850-cfm four barrel, both feature a high-flow main body with screw-in air bleeds. Metering blocks and the throttle base are constructed of billet material. Internal metal parts are made of stainless steel to withstand the corrosive qualities of ethanol fuel. The die-cast aluminum fuel bowls have glass sight windows for easy float-level adjustment. Pro Max's E85 carb should be available by the time you read this, at a price around $650.

Promax Carbs and Performance Parts
Dept. MF
30 Gasoline Alley, Ste. A
Indianapolis, IN 46222
(317) 484-1451

Quick Fuel Technology
QFT Q0750-E85 Carburetor
The fuel system specialists at Quick Fuel Technology now offer the new 750-cfm Q-750-E85 performance carburetor. It's specifically calibrated for E85 fuel. Quick Fuel calibrates the billet metering blocks, which are also available as a separate kit, and they adjust air bleed sizes and power-valve settings at the factory for easy tuning. Since ethanol can deteriorate rubber components, special E85-resistant accelerator pump diaphragms are used in the carb. The aluminum fuel bowls are coated for corrosion protection, and the floats are alcohol-resistant. This high-performance carburetor features a billet throttle body, tunable mechanical secondary activation, Teflon-coated throttle shafts, and stainless steel throttle plates. The E85 carb comes with dual inlets for superior fuel flow and sight windows for easy float-level adjustment. We found PN Q-750-E85 for $736.95.

Quick Fuel Technology
Dept. MF
129 Dishman Ln.
Bowling Green, KY 42101
(270) 793-0900