UltraViolet,
Thanks for mentioning that Honda Civic from the 1070's. (oops 1970's.) That prompted me to search. It jogs my memory and now I remember Honda advertisements of their CVCC engine cars. Here's an article I found.
"In 1970, the U.S. passed the Clean Air Act of 1970, which set the scene for emissions standards and emissions control equipment such as the catalytic converter. In Japan Soichiro Honda of Honda Motor Co. introduced the CVCC stratified-charge engine, which not only met the U.S. emission standards without a catalytic converter but also met the stringent Japanese emission standards."
The rest of the article is here:
http://www.sae.org/automag/bestcar/08.htm
Another article of interest:
" In 1975, Honda introduced its first high-fuel-economy, low-emissions achievement, the Compound Vortex Controlled Combustion (CVCC) Civic. It was the first vehicle to meet the 1970 Clean Air Act standards without using a catalytic converter, while running on regular gasoline. "
http://www.popularmechanics.com/automotive...vic/print.phtml