More efficiency and power without turbochargers.
With increasing frequency, engines are becoming more fluid with various means of altering performance and operation. Variable valve timing, fuel injection, and cylinder deactivation are all examples of how improvements to the engine have managed to give computers and the driver precise control to ensure that performance and gas mileage are optimal at all times. However, the limit is only at the threshold of an engineer’s imagination, so it’s a good thing that Honda has them in droves.
While part of Honda's team works on other versions of the NSX, the other half of the team has filed a patent for an engine that breaks all the rules. In modern motors, a cylinder has the same displacement as the others. This means that a 2.0-liter four-cylinder engine has 0.5-liters of displacement per cylinder. According to Honda’s newest patent, new cars may stop this practice with engines that have different displacements in each cylinder. Having cylinders that are each different sizes would greatly benefit cylinder deactivation technology. If a four-cylinder engine with this design has a large cylinder, a small cylinder, and two medium sized cylinders, then a computer can chose which cylinders to deactivate in order to optimize power and efficiency.
In the case of even the newest engines from high-tech manufacturers, turning a cylinder on or off meant that there were only two options for power variation, but a design with multiple displacements would let the engine chose which cylinders to shut off and which ones to keep on in order to strike the power/efficiency balance. The cylinders themselves would have equal bore sizes, but a variation in the crank throw radius would provide the difference in displacement. In order to reduce vibration on the crankshaft, the cylinders would need to be arranged with the largest displacement cylinders in the center and the smaller cylinders on the sides. The patent was published in January this year and hopefully a working version of the technology will soon follow.