Part of our
X-Prize journey led us to the
PCV system. On the surface, the PCV system is extremely straight forward(right?). When a piston moves upward on the compression or exhaust stoke, crankcase volume increases creating a slight vacuum. When the piston moves downwards on a Power or Intake stroke, volume decreases creating a pressure in the crankcase. Some small engines use this pulsing pressure differential to power a fuel pump.
Let's add to the equation the effects of "blow-by gasses". There is chemistry happening inside the combustion chamber. Extreme combustion chamber pressures are isolated by simple "piston rings". Believe me, they are NOT perfect. When extreme pressures are generated inside the combustion chamber, at least some "stuff" gets past the piston rings. When that happens, where does that pressurized physical matter go?
To try to create a mental image, if you could watch a really old car engine while idling, there would be a "blow-by draft vent tube" attached to a valve cover. The outlet of this tube would most likely discharge a visible "smoke". Similarly, an older small engine would have a vent tube connected to a "valve cover" discharging to atmosphere, from which you could observe visible "smoke". Diesel engines are even more profound with the visibility of "smoke" they discharge from their crankcase ventilation system dump tube.
Since every gasoline powered automobile starting in 1964 (in the US) has had a PCV system, it made sense for us to pay it considerable attention. The US EPA has postulated that the toxicity of the crankcase gasses generate a considerable environmental threat. Recycling those gasses back into the intake charge — where they stand a chance of being burned — will reduce Combustion Efficiency, slightly increasing exhaust emissions, but the
net emissions would be reduced. EPA chose the overall
net benefit. We researched and found that, unless otherwise regulated, NO RACE CAR USES PCV IF THE RULES DO NOT DICTATE IT!!
For the X-Prize competition, we had to comply with EPA standards. Since we had to recirculate crankcase gasses back into the intake charge, we questioned "can we make it better?" We found the
Smart Emissions Reducer chemically could break down heavy HC blow-by contaminants to a point where the combustion process could better burn them. This was proven at FreeCol Labs in western Pennsylvania, where the crankcase gasses going into the SER, and the output gasses coming out were also quantified and qualified. That (expensive) testing showed conclusively that the SER fractionalized and ionized the PCV gasses.
After the competition we continued to use the Sonata for development work. We added a vaporizer we called internally the Stratifier. It’s an aluminum block with a cone-shaped interior, with a coolant jacket to heat the physical block. The PCV gasses leave the valve cover, enter the Stratifier at the base of the cone at the tangent, spiral around the heated walls, and exit the apex. At the center of the base of the cone is a fuel injector. Itspritzes a very minute amount of gasoline into the PCV charge which gets homogenized and vaporized in the cone shaped “tornado”. The outlet then fed into the Smart Emissions Reducer.
The benefits were 2-fold; we added gasoline vapor to the combustion process to improve flame propagation rate, and we catalytically fractured and ionized the PCV gasses making them not only more combustible, but also somewhat of a combustion accelerant in their own right. Adding the fuel vapor upstream of the SER enabled the entire charge to be more molecularly homogenized in size (plus being ionized); meaning the overall charge was significantly more combustible.