New Engine Reformulates Its Own Fuel

Southwest Research Institute has developed a novel 4-cylinder engine that uses one cylinder to create a hydrogen-rich mixture that feeds back to the other three cylinders for enhanced performance.

The San Antonio, Tex.-based institute reports that preliminary test results show its modified 2.0-liter design delivers 10%-15% lower fuel consumption than the original engine. SwRI presented the engine and demonstration vehicle last week at the SAE World Congress in Detroit.

The institute notes that its so-called dedicated exhaust gas recirculation system delivers results without the need for direct injection or variable valve timing. The patented design uses turbocharging and supercharging to enhance low-end torque.

The system allows one cylinder to run with as much as 40% excess fuel. The cylinder contributes power to the crankshaft but directs its exhaust, which is rich in hydrogen and carbon monoxide, back into the intake stream of the other three cylinders.

The returning exhaust gases are cooled and looped into a patented mixer that blends the reformate with fresh air and delivers up to 25% recirculated exhaust gas to the three normally operating cylinders. Developers say the unusual architecture can be integrated with virtually any spark-ignition engine design.

The hydrogen-rich EGR helps stabilize combustion while accelerating flame speed and enhancing knock tolerance in the three normally operating cylinders, according to SwRI. The system also improves cold-start emission by accelerating catalyst light-off.

The institute is pursuing multiple joint development projects. It says an unnamed major engine manufacturer plans to put the technology into production in 2018.