CVCC

CVCC, short for Compound Vortex Controlled Combustion, is an internal combustion engine technology that Honda Motor Company developed and trademarked to meet the tightening vehicle emissions standards of the 1970s. The name describes its design: compound refers to the use of two combustion chambers, vortex refers to a vortex generated in the main combustion chamber that speeds up combustion, and controlled combustion refers to combustion occurring in a timely, regulated manner. A secondary auxiliary inlet valve fed a richer air-fuel mixture near the spark plug, while the main inlet valve supplied a leaner mixture to the rest of the chamber, and this dual-mixture arrangement let the engine burn more completely and cleanly. Because CVCC met emissions limits through combustion design rather than exhaust treatment, Honda vehicles fitted with it could pass the standards of the era without a catalytic converter, a real advantage while that emissions-control technology was still new and unproven.