How Car Engines Work" Have you ever opened the hood of your car and wondered what was going on in there?
A car engine can look like a big confusing jumble of metal, tubes and wires to the uninitiated. You might want to know what's going on simply out of curiosity. Or perhaps you are buying a new car, and you hear things like "3.0 liter V-6" and "dual overhead cams" and "tuned port fuel injection. " What does all of that mean? Exhaust gas recirculation. History[edit] The first EGR systems were crude; some were as simple as an orifice jet between the exhaust and intake tracts which admitted exhaust to the intake tract whenever the engine was running.
Difficult starting, rough idling, and reduced performance and fuel economy resulted.[3] By 1973, an EGR valve controlled by manifold vacuum opened or closed to admit exhaust to the intake tract only under certain conditions. Control systems grew more sophisticated as automakers gained experience; Chrysler's "Coolant Controlled Exhaust Gas Recirculation" system of 1973 exemplified this evolution: a coolant temperature sensor blocked vacuum to the EGR valve until the engine reached normal operating temperature.[3] This prevented driveability problems due to unnecessary exhaust induction; NOx forms under elevated temperature conditions generally not present with a cold engine. EGR in spark-ignited engines[edit] Reduced throttling losses. Catalytic converter. A three-way catalytic converter on a gasoline-powered 1996 Dodge Ram Van A catalytic converter is a vehicle emissions control device that converts toxic pollutants in exhaust gas to less toxic pollutants by catalyzing a redox reaction (oxidation or reduction).
Catalytic converters are used in internal combustion engines fueled by either petrol (gasoline) or diesel—including lean burn engines. The first widespread introduction of catalytic converters was in the United States automobile market. Manufacturers of 1975 model year equipped gasoline-powered vehicles with catalytic converters to comply with the U.S. Device Uses Solar Energy to Convert Carbon Dioxide into Fuel.