He says the engine could be up to about 30 percent more efficient than a standard diesel engine, depending on the engine load and speed. Shedd, working with graduate student Matthew Carlson, developed thermodynamic models demonstrating the engine’s potential and helped design parts that would be exposed to particularly high temperatures.

Shedd and Carlson have worked to ensure the K6 engine could function as advertised. They compare its performance to that of traditional engines. They also have worked with Kashmerick to help him design parts of the engine that will be subject to high temperatures.

Thanks to a U.S. Department of Defense Small Business Innovation Research (SBIR) grant, the team can now create a physical prototype. Shedd says the prototype will allow detailed testing of the engine’s actual capabilities, and bring the technology closer to commercialization.

According to Shedd, what’s unique about the engine is not so much its individual mechanisms, but rather, the combination of the external combustion engine with the six-stroke cycle.

“The K6 engine represents a unique combination of previous concepts,” he says. “In addition, many new engine concepts require some really special parts to function, often so ‘special’ that they can’t be made in reality or can’t be manufactured in mass quantities.”

In contrast, he says, the K6 can be made by modifying existing diesel engines in a way that is both realistic and manufacturable. Furthermore, the K6 wouldn’t require computer control for operation, making an individual engine as much as $100 cheaper, and much simpler to build.

On the down side, the engine requires extra rotations to perform the extra strokes, meaning the process loses more energy to friction and has less power. “Testing of the prototype should demonstrate the engine is still a winning combination for some types of uses,” Shedd says.

“Our modeling results suggest that not only does the engine seem feasible, it is possible its performance and efficiency could rival traditional engines, particularly at part-load operation where many utility engines operate,” Shedd adds.

Among the engine’s potential applications are power washers, electric generators, lawn equipment, welders, marine propulsion and even hybrid vehicle engines, which rarely run at full power.

Shedd says he expects to have a prototype running by late fall or early winter.