The EPA does not mandate the automotive manufacture's specification of equipment to meet emission standards. It does regulate the fuel. Air pumps were a stop gap measure by the automotive manufacturers to lower unburn hydrocarbons, HC. Air was injected in the exhaust port to enhance the final burning of the unburned hydrocarbons (fuel). Dilution of the exhaust gases does not lower the emission readings as it is measured on a grams/mile basis. Or as they say in industry:
Dilution is not the solution to pollution.
I am not aware of the automotive certification test required in the late 1960's.
As far as temperatures seen by the exhaust valve being elevated are concerned, I don't understand the direct connection with the catalytic converter, especially with the modern low restriction monolith convertors. The earlier pellet type converters had significant back pressure, which restricted flow. Air was also injected into some 3-way converters. Maybe this increased temperatures at the exhaust valve by reducing exhaust flow. Running very lean air/fuel ratios can extend the burn phase time, maybe also raising exhaust temperatures.
I'm one who's glad that automotive emissions have been reduced 90%. The reduction has been costly and a pain in the butt at times. With modern fuel injection systems, ignition sytems, combustion chamber designs, and the monolithic catalytic converter, engines are more efficient, pollute less, and last longer.
Ever stand behind a 1960's or 70's vehicle for long when it's running, especially one that's been hopped up? It will choke you up in more that one way. Yes, the EPA can be unyielding and draconian at times. So can the automotive manufacturers too. In the last several years a high speed test reaching speeds of 80 mph was added to the emission certification test cycle. The reason was that the prior certification test only called for speeds to 55 mph, and manufactures such as Cadillac had different fuel injection program maps for vehicles speeds above 55 mph that did not meet the intent of the emission standards.
I have worked with air and water emission standards programs in industry, and yes the EPA and state environmental programs can be bureaucratic, misguided, deceptive, naive, and lacking results/dollar value at times. They have made a tremendous impact on our enviroment. Remember when the Ohio River was declared a fire hazard.
You in the "Peoples Republic of California" have addition problems with 1) sensitive environmental conditons due to geographical concerns - winds mountains, valleys, sunlight and 2) being in the "People's Republic of California" where government is "suppose" to solve, and therefore have its hand in so many issues.
Related emissions websites:
http://www.epa.gov/reg5oair/mobile/history.htm http://www.epa.gov/otaq/ld-hwy.htm
