Carburetor vs. EFI

QFTMarineCarb_tnThe age old question: mechanical carburetor or electronic fuel injection? Lately, the questions seems to be more, are carburetors even worthy of being considered?

We like carburetors, they are an incredibly efficient, simple and effective system to atomize a mixture of air and fuel into an engine, and that's why they lasted well over 130 years. The first patent for a carburetor dates back to 1883, by Karl Benz (yes, of Mercedes Benz fame) and predates even the internal combustion engine. And over a century, they have evolved like all systems do when hundreds of engineers spend time perfecting them. The modern carburetor is a far more sophisticated device than the original unreliable guzzler, but still retains the simplicity of operation that makes a carburetor so easy to own and maintain. In fact, America's premier racing series, NASCAR, ran carburetors exclusively for over 60 years until 2012. Obviously, a multi-billion dollar enterprise would not put an unreliable technology at the heart of its show.

Where carburetors have always been less than stellar is during low throttle/RPM operation and under changes of altitude or temperature. This is because although they can be calibrated to very exacting specs, this "mapping" is unique and not adaptable to changing conditions. But this is more of an issue with automobiles that spend long eriods of time idling on red lights in stop-and-go traffic, or traveling up to the mountains or starting during cold winters. Here, carburetors tend to compensate by overflowing their bowls with fuel and burning large amounts of it, not even being able to completely burn all of it, thus leading to their reputation as gas guzzlers and heavy polluters. BUT, the marine environment is a different thing altogether. Changes of altitude are simply non-existent and cold starts not quite an issue down in Florida, and as for the low speed inefficiencies, they can be set up to account for those periods, which are rather short out at sea.

Our marine carburetors are custom made by a company that is at the pinnacle of carburetor innovation and production, Quick Fuel Technologies. They are engineered for the demands of the marine environment and are further calibrated by our assemblers for the specific architecture of each of our engines. They boast technologies like multiple fuel pumps, vacuum secondaries, changeable idle air and high speed bleeds, black diamond coating, etc. Coupled with our equally outstanding ignition system, our carburetors achieve instant starts, strong, smooth idle and great open throttle operation. And they do so at very efficient combustion levels. In fact, we are in the process of taking one of our carbureted engines to a State controlled Vehicle Emissions Testing Station, as we are certain it would pass the test! A Medusa engine fitted with a QFT carburetor burns cleanly, efficiently and achieves the same AFR (Air to Fuel Ratio) of an Electronic Injection System at cruising speed, making both equally capable of the same power output and fuel economy.

And yes, we also like Fuel Injection, it is undoubtedly a more effective way to control fuel economy and the manners of an engine, mostly because all engine parameters can be measured and changed through the ECU unit. This allows an EFI system to compensate for the inefficient idle times as well as the open throttle ones and always refer to a map that takes all parameters into consideration and adjusts for the highest horsepower at the lowest fuel burn. But with this capacity to tweak so many factors affecting engine operation comes increased complexity, more running parts, a fuel delivery system that is vastly more prone to failure AND much higher operational costs. The replacement of a couple of injectors or a sensor coast as much as brand new carburetor! And while we do believe that EFI is certainly a more advanced system than carburetion and understand that many boaters indeed prefer the comfort of digital readouts and predictable operation, and to that end we source our EFI systems from Holley, the same company that provides the fuel injection used on NASCAR, we still stand by our assessment that, for the marine environment, the advantages of EFI over carburetor are so minimal as to be negated by the higher expense.