Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. CVCC is a trademark by the Honda Motor Company for a device to reduce automotive emissions called Compound Vortex Controlled Combustion. This technology allowed Honda''s cars to meet United States emission standards in the 1970s without a catalytic converter. A type of stratified charge engine, it first appeared on the 1975 ED1 engine. The 1983 Honda Prelude used a CVCC design and a catalytic converter to reduce emissions, called CVCC-II along with 3 separate side-draft carburetors. The following year a standard cylinder head design was used and the center carburetor was dropped.