onda developed the CVCC engine technology in 1973 in order to reduce car emmissions. The CVCC (Compound Vortex Controlled Combustion) reduced carbon monoxide and hydrocarbon emissions by the creation of an additional auxiliary inlet valve that allowed an engine to run smoothly with a lean air/fuel mixture in the cylinder area and a rich air/fuel mixture a the spark plug (either condition which would normally produce an engine that ran rough or not at all).

The CVCC engine from honda was so successfull at reducing emmissions that it allowed Honda to pass strict US emmissions laws without the use of a catalytic converter. Ward’s Auto Magazine calls the Honda CVCC one of the top 20 engines of the twentieth century!

According to Honda “(the) CVCC engine, delivered clean emissions and excellent fuel economy. The CVCC was based on Honda’s Low-Emission Engine Method, where the engine’s combustion process itself produced lower emissions, eliminating the need for a catalytic converter to treat the exhaust gas.”

After damning research by a Japanese doctor in the mid ’60s that exposed unusually high levels of lead concentration in residents that lived near the roadside and connecting that to car emmisions, Honda assembled a team of 10 R&D engineers and created the Air Pollution Research Group.

Formed in 1965, this research group’s mandate was to develop low emission engine technology in anticipation of the companies future plans to vastly expand it’s export activities. In a radical – and successful – twist, the Japanese research team decided to NOT follow the trends of the other auto manufacturing companies as they believed that it would only put them in the same place and not provide any competitive advantages.

They decided to investigate the development of leaner combustion by using a ‘pre-chamber’ which had been used in diesel technology, but not a standard feature in traditional gasoline engine designs.

That fore-sight to take a different route ended up in the development of the CVCC engine: C (“Compound”) represented the engine mechanism with two combustion chambers: main and auxiliary. V (“Vortex”) represented the vortex, or swirl, generated in the main chamber. Caused by a jet of flame from the prechamber injected via a nozzle, the vortex had the effect of increasing the speed of engine combustion. CC (“Controlled Combustion”) represented the engine’s ability to properly control the speed of combustion (from Honda)

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