Government Versus Startup: Innovations On The Engine

Brian Robards

Brian Robards has been a car nut since he did his first cam swap at the age of 13. Currently he spends his days at Daimler Trucks with roles in engineering, operations and special projects. Before his time at Daimler he worked at Garrett Turbochargers and Holset Turbochargers as an engineer, as well as owning a small performance automotive business. Brian has a Mechanical Engineering degree from Cal Poly, an MBA from Washington State and is currently enrolled in University of Wisconsin’s Engine Systems program. On his off time Brian likes to spend his time turning wrenches in his shop or drag racing. Here is best option for you to do bachelors degree in  mechanical engineering which is awarded by the University of West England. 

The original Otto cycle engine was first produced in 1876 and the Diesel engine came just 14 years later. In the past 120+ years there have been several revolutionary changes made to the internal combustion engine, but even so, the best modern engine is only 50% efficient at turning fuel energy to mechanical energy. At the current rate of advancement it could be another 100 years before we find the next 10% in efficiency improvements. However, due to the US Government’s SuperTruck program, there have been recent advancements, and the industry could see an evolutionary leap in efficiency in the next 5 years from several engine Startups.

The SuperTruck program was initiated by the US Department of Energy in 2010, with the aim of increasing engine efficiency by 20% through a public-private partnership with some of the largest companies in commercial trucking including Cummins, Daimler, Navistar and Volvo. Though many engine technologies were investigated as part of this program, the majority of the OEMS settled on Engine Downsizing and Waste Heat Recovery as the primary means to boost engine efficiency. A waste heat recovery system is inserted into the exhaust system of the truck and uses the thermal energy released through the exhaust to boil a fluid. This then drives a turbine that is connected to the crankshaft via a gear train. These technologies hope to improve engine efficiency by 10% compared to the existing commercial vehicle engines.

While most of the SuperTruck technologies are focused on adding devices to the traditional engine to recapture some of the wasted energy, there are several engine startups which are completely rethinking the internal combustion engine, and are promising some very impressive results. The two approaches which are currently being investigated are to use opposed piston engines, or to utilize an over-expansion engine.

The opposed piston engines aim to reduce the amount of heat energy lost to the coolant system by getting rid of the cylinder head and utilizing two pistons per cylinder. The pistons travel toward each other to create a combustion chamber. The primary advantage of the opposed piston engine is that by removing the cylinder head they can significantly reduce the allowable surface area for heat energy to escape the engine which results in improved efficiency. Three companies which have made significant strides in developing opposed piston engines are Ecomotors, Achates Power and Pinnacle Engines, and all are promising over 15% improvements in fuel efficiency with their engine technologies.

With a modern four stroke piston engine, when the piston reaches the end of the power stroke there is high combustion pressures still available in the cylinder. This pressure is allowed to escape when the exhaust valve opens. The over-expansion engine aims to solve this problem by making the engine have two different displacements depending on which stake in the combustion process it is in. The Scuderi Group has developed a split cycle engine where the intake and compression stroke happen in one group of cylinders, then the combustion gases are transferred into another set of cylinders for the expansion/exhaust stroke. By designing the expansion cylinder to be almost twice the displacement as the compression cylinder, the Scuderi design minimizes the energy lost through the exhaust and results in a significant improvement in engine efficiency.

It is an exciting time for the engine industry, there is a renewed interest in improving fuel efficiency and innovative technologies are being developed by companies small and large. We may very well see some evolutionary leaps in the engine industry in the very near future, and the organizations responsible for these changes may be completely unknown today.