The Renesis, Mazda's Revolutionary Rotary Engine
Aug 16, 2003 | By: Matyas Varga - SRO
Nearing the end of the 19th century, Henry Ford first invented the internal combustion engine. The concept was based on the idea that the appropriate mixture of fuel and air, once compressed could emit a large enough body of force to displace a significant mass (this is known as the measure of torque). Henry Ford later implemented the idea into the conventional system whereby a combination of valves and pistons could be used in manner so as to direct this pressure into a cranking mechanism. The system was moderately different to that which had been previously put into use in the steam locomotive engine. However, the internal combustion system differed in that it provided far more displacing power then the pressure derived from boiled water. The original concept, though simple, paved way towards a century of refinement. The idea was truly unique and so perfect that very few dared to diverge from the concept.
Rather then trying to compete through alternative designs, the automotive industry to a large degree spent the last century developing the concept in attempts to derive the most efficient and yet powerful system. While cars have changed allot since the model-T was first introduced, the very basic idea behind the means through which to propel the wheels remained the same. Henry Ford's Idea was truly evolutionary. While many attempts to develop alternative systems have gained significant ground in hopes of achieving cleaner means of transportation. (A couple of examples would include electric motors and hybrid engines). None of them measured up to the practicality and world wide acceptance that the gas engine had received. This strive towards alternatives can be seen as a sign that Henry Fords concept had been exhausted on the grounds that all means towards refinement are more or less reaching close to what may be considered a terminal stage in development. Not to say that all means of development have been exhausted. Rather, the rate at which the system of efficiently producing displacing power is developing at a marginally decreasing rate. In other words, the internal combustion engine, in the period between 1990 and 2000, has developed to the degree that the means by which to derive more rotational force from a cranking mechanism is slowly being exhausted. While I don't rest my case on claiming that there is no more room for development, I do however wish to base my argument on the simple fact that the marginal rate of development is diminishing. While it may be true that variations in means of compression (Turbo Chargers and Superchargers) might introduce more pressure into the combustion chamber, and thereby achieve more "efficient" output, there is only so much room for improvement. At some point or another, the physical properties of the materials used in the system deplete in their ability to withstand the sort of force and pressure emitted by such high output engines. To illustrate this case, take the example of some of the more developed drag racing engines achieving over 30 PSI intake pressure. Most of them can barely endure more then one or two runs down the track. And this doesn't even account for the issue of practicality. The output of these engines across the rev range is so sporadic so as to render them absolutely useless to any other application other then a quick bolt down a straight quarter mile. And let's not even discuss efficiency. The case is further illustrated by the divergence of Formula One technology towards a naturally aspirated system.
So where am I getting to with all this you ask? The basic point is that in terms of its application into a practical and more controllable high performance machine which requires consistent rotational output across the rev range, the internal combustion system while sticking strictly to the cranking concept as first derived over two hundred years ago in steam locomotives has almost exhausted all its means towards improvement. So where do we go from here? Well, the clear and obvious answer is to find an alternative system. However, certain restrictions come into play. For instance, we have witnessed a lack of adoption from various hybrid and electric alternatives. This is mainly due to the populations' unwillingness to compromise the convenience and accessibility of the modern gas station. While it is true that we may provide alternative fuels, the basic fact is that aside from gasoline, other forms of fuel just don't cut it in terms of cost and safety. While hydrogen is has been an interesting proposition, I sure as hell wouldn't sit in a car with the potential to blow the planet into a million pieces. And again, even with the adoption of hydrogen powered cars, as BMW proposed, the case of the conventional cranking systems ability to withstand the pressure remains questionable.
So all these points put together brings us to realize two things. The first is that we need to continue to develop the efficient power output of the internal combustion engine, not just to meet the needs of an ever demanding motor sports industry, but also to reduce our current rate of natural resource depletion. The second realization is that we need to achieve all these goals in light of the fact that the system on which we've relied on for so many years is slowly depleting its ability to meet these demands. To this end, I propose that the adoption of Mazda's newest Rotary Engine (The Renisis) is, just as they claim, truly a huge evolutionary leap and not just another marketing gimmick. While revolutionary within the scope of the internal combustion system, it is certainly not revolutionary in the sense of revamping automotive technology. So while their marketing strategy labels it as "revolutionary" it does so simply to parallel its mechanical operation. And at 270 degrees per thermodynamic stroke encompassed in a smaller size, coupled with reduced weight and a lower centre of gravity, The Renisis is sure to be a real winner.
- For a more technical overview of the rotary engine, direct yourself to the following link on Mazda's site: Rotary vs. Piston, Know your enemy - by: Jim Mederer (Racing Beat)