GM Steps Up Ignition Research

General Motors Corp. is teaming up with Robert Bosch GmbH and Stanford University in California under a 3-year, $2.5 million program to perfect Homogeneous Charge Compression Ignition (HCCI), a spark-less combustion technology auto makers have been struggling for 25 years to master.

HCCI engines have the potential to increase fuel efficiency by as much as 20%, GM says, over conventional powerplants.

The technology also could produce near zero particulates and oxides of nitrogen (NOx), enabling fuel-efficient diesel engines to meet the forthcoming stringent U.S. emissions regulations.

HCCI uses a combustion process similar to diesel engines, but at a lower temperature and a different air-to-fuel mixture than conventional ignition technologies.

The lower temperature virtually eliminates NOx emissions and reduces throttling losses, which leads to improved fuel economy.

Rather than using a spark plug to ignite the air-fuel mixture, HCCI technology compresses the blend with the piston until the rising temperature inside the cylinder chamber causes spontaneous combustion.