Keith Brown
Active VIP Member
Thank you for the explanation I appreciate it, but I have trouble believing the science behind displacing oxygen in the combustion chamber in a effort to reduce emissions. It is counter intuitive to me. Any fire that I have ever dealt with burns cleaner with more oxygen. A case in point the Big Dogs that are rolling coal every chance they get are simply over fueling. There just is not enough oxygen available to support compete combustion so the un burnt fuel go out the pipe. You can get your gas lawn mower to do the same thing just don't clean the air filter. In any case I brought up the "AIR" pump GM use in the 70s in my first post because I just don't believe some of the sh#t we are fed. It does have me thinking though, that if I am wrong I should do more. Like run a pipe from the exhaust of my lawn mower to the air intake. Thanks again.
The EGR system reduces the NOx or nitrous oxide emissions of the engine, NOx are created because oxygen combines with the nitrogen in the air under high heat and pressure, so by circulating exhaust gas back into the engine there is less oxygen to form NOx as well as less heat involved in the combustion cycle to form the NOx. Now the argument is being made that the EGR system could be removed from new diesels completely because the SCR (DEF) system also removes NOx by injecting urea into the exhaust and passing it over a catalyst to turn the NOx into water and nitrogen.