ExclusiveTech Articles

Universal Tech – Understanding Alcohol Fuels: Part I

The use of alcohol as a fuel in race cars, specifically open wheel and in some closed wheel cars, has been the standard for many years. Many of us may not realize or understand why this is the case.
When comparing alcohol to gasoline on the surface, it is not obvious why one would select alcohol over gasoline. The common answer is that alcohol makes more power. But gasoline is much denser from an energy content perspective and that makes gasoline on an energy-available perspective a much lighter fuel. It takes less to make the same power. The energy potential versus the weight of the fuel is what makes gasoline lighter and seemingly a more logical choice. It is also easier to ignite gasoline than alcohol fuels.
When we talk about alcohol fuels, we are referring to methanol and ethanol-based fuels [there are some significant differences that we will cover later]. Gasoline is available all over the world, the quality and the chemical blending may be different based on local government requirements, but it is available everywhere. Gasoline is also more compatible with the materials that are currently used in the construction of fuel systems in use on the road today, from inside the car and the infrastructure used to move fuels from the producer to the customer that is what is currently utilized. However, gasoline, particularly racing gasoline is not the same all over the world. The fuel used in race cars at the highest levels may be called gasoline but the only similarity between many of these fuels and what the Saturday Night racer calls gasoline is the nomenclature alone.
The characteristics, between the gasolines used in say a NASCAR Cup car and a F1 car are worlds apart. It would be easier to get a date on Saturday night with the latest en vouge movie starlet than to buy 55 gallons of the “gasoline” used in a F1 car. It is pretty much unobtainable to the average racer. That said we are still able to buy racing gasolines that are a far cry from what is available at the pump today. We have available at our fingertips, if we can pay, some of the finest racing fuels that have ever been offered to the racer at any time in history. We are a truly lucky lot. While we pay for this privilege, the cost is very reasonable given the amount of technology and infrastructure it takes to manufacture and deliver these high-quality products.
It is instructive to look back to why alcohol was even introduced to the racing community. It boils down to one word, SAFETY. Yes, there are other benefits but the fuel was really legislated into use due to perceived safety benefits. The great things about gasoline and its use in racing engines is also why it is inherently a riskier fuel than alcohol – gasoline will ignite in less-than-ideal conditions, especially outside the engine. And, once it is lit, it is considerably harder to extinguish outside of the controlled burning that is taking place in the combustion chamber of our engines. If you have ever been present when a race car catches fire it is a truly scary event. It is scary regardless of the fuel used. But gasoline is a bit more intense. The bright orange of the fire, the very intense heat and the fact that spraying water on the fire does very little to the fire other than spread it around. I am not suggesting banning gasoline as a fuel for racing; I am just stating a fact. The fact that fires are a very rare occurrence in today’s racing cars is a testament to the safety that is designed into the modern race car’s fuel systems, at all levels of the sport. A condition that was paid for by the fellow racers that perished or were injured in the past in gasoline fires.

A car that is fueled by alcohol is no less scary should it catch fire but there are a few critical differences. The fire is much easier to extinguish with water-based fire extinguishers. In fact, water is the extinguisher medium of choice for alcohol fires. There is less need for special extinguishers to be used outside of the car itself. This goes back into our racing past – in 1964 when there was a crash and a terrible fireball due to a ruptured fuel tank early in the Indy 500 and two prominent Indy car drivers of that time, Eddie Sachs and Dave MacDonald, perished as a result of that fiery crash. The following year, in 1965, all the cars racing under the USAC banner including the Indy 500 were powered by methanol as the use of gasoline was banned. Some other alcohol facts that make it a bit safer from a fuel perspective, it burns at a much cooler temperature and slower than gasoline. Consequently, this slower burn rate around 18 to 22% slower depending on the conditions, results in an open fire that is a bit less intense and easier to control with easily obtained firefighting equipment. Please do not confuse this as a “safe fire”; any fire that is unintended is a scary and serious matter!
But not everything is all roses and honey from a safety perspective. In the light of day, it is almost impossible to see an alcohol flame. While it is easier to extinguish an alcohol fire, first you have to see it to extinguish the fire. Often times you will see the driver or crew reacting to the fire before any pit personnel can see the flames. Their reaction is due to the fact they are being burned. Think back to the Indy 500 when Rick Mears was burned by a fire ignited during a pit stop. This was the genesis of Indy car teams squirting water on the re-fueling interface, right after it is disconnected from the car as a fire mitigating process. As a fuel, alcohol is to be treated with the same respect as any other fuel. It is dangerous and can cause some serious injuries just like any other combustible liquid. The same level of care should be exercised when dealing with alcohol as you would with gasoline.
For the racer, there seems to be as many positives for using alcohol as a fuel; are there any negatives? Yes, there are a plethora of issues that alcohol brings to the party that are not even considerations with gasoline fuels. The first is that alcohol is hydroscopic. It will absorb water out of the air if it is exposed to the environment. This little feature can make a perfectly acceptable jug of fuel not worth using if the water content gets too high. This feature of alky fuels is and has been the bane of many a tuner as they make changes to the fuel system only to find that the fuel was contaminated with water. This is a real problem in areas that have a good bit of humidity in the air. In the Southwest it is not a big issue but it still means that any alcohol that is stored needs to be in containers that are not vented and that the fuel should not be exposed to the environment any longer than possible. While gasoline that is exposed to the environment also loses its potency, as the light bits (from a molecular level) of the fuel evaporate and it is those lighter compounds of the fuel that differentiate racing blends from pump gas. Another downside is that many of the “rubber” seals that are used in gasoline fueled cars do not hold up when the fuel is changed to alcohol. They do not react well with alcohol fuels, often degrading and no longer offering acceptable performance or even worse they degrade and contaminate the fuel downstream of their location. They can also cause seals to degrade to the point of failure and then the damage is even worse. While this seems like a real issue, it is simply rectified, by using seal materials that are resistant to alcohols, from the tank to the end of the fuel delivery system.
The chemical makeup of alcohol is very corrosive to many of the coatings that are typically used on metals in the fuel system. Many of the coatings that are designed to protect the metal components in the fuel system are easily attacked by alcohol. It is not uncommon for metal components to get surface oxidization and pitting as a result of alcohol fuels. This becomes a real issue if the alcohol is allowed to sit in the fuel system between races. The fuel system should be maintained between races to prevent the alcohol in the system from turning into what is a very strong corrosive agent. If the fuel system is not cleaned frequently, preferably after each race day, the corrosive nature of alcohol will play havoc with the metal and rubber components in the fuel system, especially those components not designed for this type of fuel. This is not a real issue as most racers who are using alcohol fuels are already familiar with the required maintenance. For those not familiar with the maintenance rigors required when using alcohol fuels; education comes quickly and with a vengeance.
Failure to properly maintain an alcohol fuel system will find that aside from the corrosion that will occur on many metallic surfaces there will be a grit like substance almost a fine sand type of residue, in the lines and around aluminum parts. This grit is the result of an increased electrical conductivity that alcohol has over gasoline fuels. The grit is from the galvanic corrosion caused by the greater electrical conductivity from the fuel as it interacts with the various different metals in the fuel system. This contamination will migrate throughout the system clogging fuel filters, fuel jets and generally cause havoc within the fuel system.
In the next issue of Dirt Empire Magazine, we’ll continue to learn more about the properties of alcohol fuels and learn more about maintenance issues and why it has become the preferred fuel for so many different types of race cars. The author can be reached at: Vahok.Hill@cox.net