Words and photos by Greg Terzian
I first became intimately acquainted with the Evinrude E-TEC engines in 2006 at an Evinrude press event in Key Largo, Florida. It was at the 2003 February Miami International Boat Show that Bombardier Recreational Products first introduced the E-TEC engines in 40 through 90-horsepower models to the boating industry. Back then, the E-TEC was the new kid on the block and its not always easy being new, and as I would find out, different.
These were the first new Evinrude engines to emerge since BRP won the federal bankruptcy auction of Outboard Marine Corporation, and with it the rights to the Johnson and Evinrude names, patents, and intellectual properties. BRP would carry the Evinrude name into the future, and back then there was a lot of anticipation and with it, a lot of questions. Will Evinrude continue its heritage of industry-leading designs and performance, or would it fade away? I certainly had a lot of questions.
It was at the Evinrude press event in 2006 that I was able to examine the new E-TEC V6 engines. I remember the moment I watched in eager anticipation as the E-TEC 250 was started. It was quiet, but it had that reassuring rhythmic pulse that only a two-stroke engine could have. There was no smoke at all, and at a low idle, the big V6 was nearly silent, with just a hint of that satisfying musical sound we all know. The sound of instant power. That sound that told me it was going to be a fun weekend, and I was not disappointed.
I also remember experiencing both exciting and thrilling emotions when those triple E-TEC 250s mounted on the back of a Wellcraft 352 were accelerated at full throttle. I found myself reaching for a grab-rail to hold on, and right then and there I knew those were not my fathers OMC engines back there. Yes, this is a two-stroke engine as I knew them, but better. And as I was taking in the experience, I began to think of the impact this new engine series would have on the industry. As is the case with all departures from expectation, Evinrude's new E-TEC would become a focal point of excitement, confusion, and misinformation.
Genesis
The development of the internal combustion engine was an important factor in the rise of the automobile. It was relatively lightweight, inexpensive to produce and produced a lot of power relative to its size. Prior to this development, efforts were explored with steam engines and even electric power, but neither of those two solutions offered the benefits of a gasoline engine. And like any technological evolution, engines became more powerful, more reliable, and less expensive. And it was the refinement of the internal combustion engine that played the most important role in the emergence of the automobile as a staple of transportation.
1897: American Motor Co. 'Portable Boat Motor'. This engine even featured a reversing gearbox! Image used with permission by Bill Grannis |
In the early 1970s, new emissions regulations began a process that ultimately became what many feared would be the end of high-performance cars forever. It was thought that the golden era of the horsepower wars among car makers was over, now substituted for decal-clad representations of those former glorious machines. And that was indeed the case for a while.
Back then, another process was also beginning to take shape, though very few people realized it would ever matter. Technology was slowly pushing back against the limitations imposed by new engine configurations that choked power. It was slow at first, but by the mid-1980s, a new revolution of technologically-driven performance cars was being born. It was this technology of fuel and air delivery that overcame the early limitations of new regulations, and today we have cars that produce incredible power as well as fantastic fuel economy and clean emissions. Nobody thought that was possible just thirty years ago, and yet the very fastest and most-capable cars are being made today, not in the 1960s. It was the electronics industry that made these improvements available. Large scale integrated logic chips became more powerful and less expensive to allow small computers to operate fuel injection and monitor engine parameters to decrease emissions and increase performance.
But what does this have to do with outboard engines? What happened to the muscle car in the 1970s repeated itself with outboard engines in the late 1990s. A very similar sequence of events was played out all over again, though with a slightly different result.
The classic two-stroke outboard engine is inherently very dirty, having little or no design features for clean exhaust hydrocarbon emissions. Although they had become much larger, the traditional two-stroke outboard is essentially the very same engine that was powering Ole Evinrudes rowboat over 100 years ago. It would only be a matter of time before these engines needed refinement for the future emission regulations. It was generally thought that the two-stroke engine would be extinct. After all, how could any engine that combusts oil as a matter of design fulfill todays emissions requirements? Most manufacturers felt that the four-stroke engine was the answer.
1962: The Homelite/Bearcat 4-Cycle 55 was the first successful large four-stroke outboard engine. This engine was based on an earlier design of an automotive engine. |
The very first Evinrude outboard engine was developed over 100 years ago and was 1.5 horsepower, but this was quite a lot of power for boaters used to rowing. Best of all, it was small and very light. It could be carried with no more effort than set of oars. Very important to its combination of power, light weight, and reliability was the two-stroke engine design.
As its name suggests, a two-stroke engine completes its power cycle in two strokes of the piston one stroke up, one down. Compression, intake, exhaust and power all take place in just two strokes, or cycles. By comparison, a four-stroke engine only produces power on every other cycle of its crankshaft revolution, thus requiring a separate intake and exhaust stroke that does not produce power.
An outboard engine must be as lightweight as possible, and yet still produce a lot of power relative to its size. Four-stroke engines are by design heavier than two-stroke engines of equivalent power output and not as power-efficient. The additional components required by the four-stroke engine design add weight, and a higher parts count potentially increases points of failure. The two-stroke engine offered the clear solution for light weight, power and reliability.
There were exceptions early on, the most successful being the 1962 Homelite Bearcat 55, which itself was a design derivative of an automobile engine. This was an outboard for a lightweight boat, but the Bearcats comparatively large size and weight for its 55-horsepower rating was outclassed by two-stroke outboards. It simply offered no compelling performance advantage to the boater.
The added complexity of the four-stroke engine and basic design of the combustion cycle meant that pound-for-pound, a two-stroke engine would generally produce more power. And in the application in which outboards are used, weight is crucial, and so the two-stroke engine seemed the logical choice moving forward.
The Irony of Precision
We tend to associate the classic image of a high-performance outboard as being what the industry was built upon - carburetor-fed two-stroke engine designs. And this is indeed true. Two-stroke outboard engines certainly evolved and became more powerful and easier to use. On some models, multi-port fuel injection replaced the carburetor, and this was definitely a step forward in terms of power and efficiency, but those systems were adapted to existing engine designs. To achieve a much higher degree of combustion efficiency, a completely new technology would be called for. Until recently, there were no outboard engines that were designed from the ground-up to be directly fuel-injected.
It is an irony that the keys to power, fuel efficiency, and low emissions are all the same - that is, precision fuel delivery and efficient combustion. Exhaust hydrocarbons are essentially the result of incomplete combustion. It makes sense that more power could be extracted from a fuel charge with a more complete combustion cycle.
The idea of lowering hydrocarbon emissions nevertheless garners negative feelings based on the impact on performance that early efforts at emissions control had on cars. Back in the 1970s, the computer technology required to deliver fuel with ultra-high precision was not yet available, however today we all see the benefits that direct injection has on high performance cars. More complete combustion not only increases power, but it lowers hydrocarbon emissions.
Using a carburetor or manifold electronic fuel injection to introduce fuel into the combustion chamber ultimately results in unburned fuel exiting the exhaust. That incomplete combustion represents not only wasted potential power, but wasted fuel efficiency and also increased hydrocarbon exhaust emissions. The more you improve combustion efficiency, the more power potential you have for less fuel consumption and fewer emissions. But was it the basic two-stroke engine design that was the problem? Many of the industry pundits erroneously thought so. They were among the many voices mistakenly prophesying the end of the two-stroke outboard soon to be banned from the waterways and regulated out of existence as they were in the motorcycle industry.
Its easy to see why this line of thinking was so prevalent, with the classic image of the smoke-spewing, sneezing outboard engine producing a trail of fuel-rainbows on the water surface. But it was not the two-stroke combustion cycle that was the culprit of this legacy, rather, it was how those engines were designed as a whole. Both two and four-stroke engines produce hydrocarbons, and both engines could be refined to more precisely combust fuel.
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