Carburetion Versus Fuel Injection
Carburetion Versus Fuel InjectionAre they making them like they used to?
Today as we peer into the twenty-first century, technology is at its prime. We biologically create life, travel to new worlds, and even create new ones within cyberspace. Yet, we do not forget the past. Even today in this technological empire we have created, I still hear the nostalgic words from my father: “They sure don’t make them like they used to.” And in many cases, he is correct. Together, my father and I are in a process of restoring a 1968 Chevy Camaro. Many times we have discussed the controversy of whether or not the 350 cubic inch engine should be equipped with today’s computerized electronic fuel injection system or the traditional carbureted system. I argue with my father that today's E.F.I (Electronic Fuel Injection) system is the wave of the future and the only way to go, but the old man continually reminds me of the way things used to be when he was young. Despite the outstanding performance of carbuated cars on the racetrack, I believe that the future of the automotive world lies in computer controlled fuel injection systems.
In order to understand the benefits of carburetors and fuel injectors, one must understand what they do. The carburetor is quite simply a fuel-metering device that operates under the logical and straightforward laws of physics. It has evolved over the years from a very simple and basic design to the complex and intricate models that are available today. Liquid fuel will not burn; it has to become vaporized by the carburetor before combustion can occur. If fuel is not vaporized then the liquid will travel through the car and out the exhaust. Once vaporized the correct fuel/air ratio must be obtained to burn properly. Fuel is discharged through 12 holes located in exactly the correct position in the venturi resulting a finely atomized mist similar to that of a paint gun spray mist (Motor World 1). The same effect is accomplished with E.F.I. by using high-pressure fuel rails and injectors. The computer electronically determines the amount of fuel the injector disperses to accomplish an optimal air/fuel ratio.
Fuel injection verses carburetion is a major issue in the automotive world. People are split 50/50 in favor of E.F.I. and carburetion (Car Craft). To most muscle car owners, the preference comes down to which one offers more power. Studies have show that a precisely tuned carbureted engine can out perform an E.F.I. equipped engine. Calibration is the heart of the carburetor's contribution. An engine can not make decent power unless the carburetor maintains precise control of the air/fuel ratio throughout the engine's operating range. Warren Johnson, a Pro Stock racer, says “there are only about two to three legitimate carb experts that can really dial in Carbs for Pro stock,” (Car Craft) while it is much easier to tune a fuel injected car. Of course, there is a price to pay for the performance edge in carburetion, and the expense is in gasoline. Fuel injected cars can get anywhere from six to thirteen addition miles to the gallon. Muscle car owners are left wondering if the little extra speed is worth it when today’s average gallon of 87 octane cost a dollar and twenty cents. And like many other accessories from the past, carburetors too are not exactly “user friendly.” Starting a carbureted car on a cold morning is often difficult. It takes a much longer time for a carbureted engine to warm up than a fuel injected engine. Through the use of a computer, E.F.I. has solved the cold start problem. Yet, carburetors have been around for a long time and many people don’t mind the inconveniences.
The idea of a carburetor first came from Henry Ford. Ford asked George Holley to design a carburetor for the Model T. Sensing. His first carburetor called the “iron pot,” (Holley) made its debut in 1904. George later created a business to accommodate Ford’s automobiles as well as Pierce-Arrow, Winston, and Buick. The business is known today as Holley Brothers Inc. Holley is now one of main after market suppliers to car enthusiasts worldwide. Carburetion has been around for a number of years. There has been many advances made to carburetors to keep them on the edge of technology, but E.F.I. is catching up. E.F.I. is just in its infancy and has only begun to make advances toward performance. At the rate E.F.I. is catching up, I believe that it is only a matter of time before it surpasses carburetion. It is the computer that will push E.F.I. past carburetion and across the finish line in the near future.
Carburetors and E.F.I both serve to atomize fuel, but do so in completely different ways. A carburetor atomizes fuel through venturies at the top of the intake manifold. In an E.F.I. system the fuel injectors are located above each intake port at the base of the intake manifold. This shortens the distance the atomized fuel has to travel to reach the cylinder. This typically helps obtain a more complete burn cycle, which increases power and improves gas mileage.
What may cause today’s car owner to favor carburetion might not be just the racetrack performance, but the experience involved in owning a carbureted car. Carburetors include vacuums and oversized manifolds that create a deep throaty sound that can never be emulated by a fuel injected system. When the driver steps on the gas, the sound of the carburetor’s two primary chambers opening sounds like a low growl. When the driver surpresses the accelerator to the floor the two secondary chambers open up which sounds like a very loud deep scream. For many American muscle car owners, this is a major “pro” for carburetors that fuel injectors can not match.
For the average American, reliability and car maintenance plays a major part in car selection. Since the early 1980s E.F.I. has become mandatory for all emissions controlled vehicles. Carbureted cars have been proven to cause more air pollution than fuel injected cars. Since then carburetors have become strictly after market items. Many enjoy dealing with them to rebuild or modify as a hobby. Carburetors are much harder to tune than fuel injectors are, although they contain fewer components. Carburetors have two screws that most carburetor owners know very well. These two screws control the air fuel mixture and idle speed. Rotate one screw on the carburetor while the car is at an idle state the engine may burn rich or lean with fuel. To find the perfect mixture of air and gas one must be a trained professional. While anyone with a laptop computer can dial in the optimal air/fuel mixture using E.F.I.’s onboard computer. E.F.I has another advantage is tuning. Edelbrock, a major aftermarket company, “takes the digital fuel injection system one step further in that the fuel curve can be modified to work with any engine; this command capability is accomplished through your IBM-compatible personal computer” (Edelbrock). The E.F.I. system allows for easy diagnostic checks on an engine. The process is as simple as plugging in two wires and watching a computer screen that will tell the owner precisely what’s wrong with his/her car. The component that the diagnostic mechanic connects to is called the Electronic Control Unit (ECU). The ECU uses sensors that determine throttle angle, R.P.M., manifold pressure, and air temperature to properly calibrate the air/fuel ratio. If that sounds like a lot of expensive equipment, it is just getting started.
In order to properly install a fuel injection system on your car you must have an electric fuel pump, fuel pressure regulator, oxygen sensor, mass air flow sensor, R.P.M. sensor, throttle positions sensor, anti knock sensor, and temperature controller. The entire E.F.I. system will cost somewhere between two thousand and three thousand dollars (Car Craft). Whereas the carbureted systems will only cost around six to seven hundred dollars, nearly one-fifth the price of fuel injection.
In January’s edition of Car Craft, journalist Marlan Davis asks Butch Bass, a Holley engineer, how long it would be until EFI outnumbers carburetors on street machines? “Electronic fuel injection may never become more popular than carburetors on street machines. Many street machines want to emulate Pro Stock race cars that still use carburetion, and they prefer the simplicity of carburetion-no return lines to the fuel tank and no electronics package to mount. However, as prices come down and derivability aspects of EFI become more widely appreciated, fuel injection will gain a much larger following.” Only time will prove whose opinion is correct. When Car Craft asked Kevin McClelland his response was “upwards of 10 years.” Car Craft also asked Jim McFarland from McFarland and Associates if he believed the carburetor was dead? He responds, “If carbs are left as they are today, with no technical improvements, they have about seven to eight years left. But there are tech improvements on the horizon that will prolong their life. Carbs will last longest in motorsports. In the future you may not recongize them as carbs, but they’ll still rely on pressure differential to meter fuel” (Car Craft). Both McFarland and Butch Bass agree that EFI will not surpass carburetors. The question is will technology for carburetors evolve the way they think? Only time will answer that.
In conclusion, my father and I have both decided on carburetion for my car. Yet the idea for a fuel injection conversion has not been ruled out. I will keep my eyes on the market for available conversion kits. As time progresses and technology advances, I find that today’s youth thirsts for the latest state of the art technology. While our parents are content with their old yet functional utilities, we tend to venture out and utilize products that just hit the market. Yet, I believe this is for the better. This adventurous spirit may be the case for answering questions, problems, and infallibility’s that may not have been answered otherwise.
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