cAlthough very little can...
cAlthough very little can be seen with the engine in the car, the system's simplicity contributes no extra hoses or lines under the hood. The tank in the foreground is a separate tank for precise fuel measurement.
At this point, many of you are probably thinking that this is in total contradiction to everything you've been taught in the past, such as cooling the intake charge for greater density and to suppress detonation. We warned you that some rethinking would be required. Such cooling is necessary to suppress detonation when the fuel is not uniformly vaporized, since some parts of a non-homogenous mixture burn quickly and other parts slowly within the same cylinder, creating turbulence and colliding flame fronts and all traditional internal combustion engines are dealing with non-homogenous, incompletely vaporized mixtures today. It is also true that the heating of the incoming mixture reduces its density and causes it to expand. On a normally aspirated engine, such expansion would just push right back out through the carburetor, but on Smokey's system the expansion is trapped in the induction system because the small turbocharger (homogenizer) serves as a one way check valve. Consequently, with the expansion contained, the induction system becomes pressurized, providing high mixture density and artificially aspirating the engine. At anything above idle, the induction system on Smokey's design has positive pressure, but that pressure comes from heating the mixture, not from the turbocharger (homogenizer).
One of the big advantages of the "expander cycle" engine is that it does not rely on high rpm to generate power. In fact, after being fitted with Smokey's system the Fiero developed the same performance at 1,700 rpm that used to require 2,200 rpm, so a lower numerical gear ratio was installed. Lower engine speeds also equate to less wear and less friction-hence better efficiency.
The beauty of Smokey's system is its simplicity, but simplicity is deceptive. Staged heating of the working liquid (air/fuel mixture), homogenization of the working fluid at the proper point in the heating process, and balanced heat management are the keys. Get one part of it wrong and the whole thing won't work. There's a lot of physics and chemistry involved, and a few of the details contained in the various patents on this design have been intentionally withheld by the Smoke, although the basic principle of operation has been explained here.
Partially visible is the wrapped...
Partially visible is the wrapped exhaust crossover pipe leading to the homogenizer in the foreground. The arm attached to the top of the homogenizer controls maximum manifold pressure. Below the carburetor and homogenizer is the exhaust-enshrouded intake manifold.
Now let's examine some of the numerous benefits offered by this high efficiency design, the most prominent benefits are performance and mileage. The design can be applied to any Otto-cycle engine, as long as the engine doesn't have direct port fuel injection. The fuel must be in the airstream for the preheating vaporization and homogenization to occur. On virtually any engine, whether it's a V-8, V-6, four-cylinder, or whatever, the system will produce roughly 1.8 horsepower per cubic inch. That would equate to 543 hp for a 302, 630 hp for a 350, 720 hp for a 400, and 817 for a 454, and in every case that power would be produced at a reasonable 5,200 rpm. Of course, nobody really needs those big horsepower numbers on the street, but 250 hp from a small, lightweight 151 cubic inch engine, such as in the Fiero, can make for a thrilling ride.
Such a reserve of power adds a margin of safety in passing or merging traffic situations, and it does it without any hint of roughness, bad idle, or poor economy. In fact, Smokey's Fiero was the smoothest four-cylinder we've ever been in.
Essentially what Smokey's "expander cycle" does is give us the means to bring back cars that are comfortable to drive with a feeling of security only a reserve of performance can supply. It has acceleration acceptable to most drivers-something we haven't had since 1972 in most vehicles. Yes Smokey's setup may be too powerful for some of the motoring public but virtually every American car built up to 1972 was that way. Smokey's design is also fuel efficient and if someone doesn't want the power, they don't have to use it. Or for those who insist, an even smaller engine using the same principles could be installed that would be less powerful and even more fuel efficient.