Early/late Exhaust Valve Closing
Early and late exhaust valve closing can also reduce emissions. Traditionally, the exhaust valve opens, and exhaust gas is pushed out of the cylinder and into the exhaust manifold by the piston as it travels upward. By manipulating the timing of the exhaust valve, engineers can control how much exhaust gas is left in the cylinder. By holding the exhaust valve open slightly longer, the cylinder is more emptied and ready to be filled with a bigger air/fuel charge on the intake stroke. By closing the valve slightly early, more exhaust gas remains in the cylinder which increases fuel efficiency. This allows for more efficient operation under all conditions.
Read more about this topic: Continuous Variable Valve Timing
Famous quotes containing the words early, late, exhaust and/or closing:
“Well, it’s early yet!”
—Robert Pirosh, U.S. screenwriter, George Seaton, George Oppenheimer, and Sam Wood. Dr. Hugo Z. Hackenbush (Groucho Marx)
“Everyone soon or late comes round by Rome.”
—Robert Browning (1812–1889)
“An entertainment is something which distracts us or diverts us from the routine of daily life. It makes us for the time being forget our cares and worries; it interrupts our conscious thoughts and habits, rests our nerves and minds, though it may incidentally exhaust our bodies. Art, on the other hand, though it may divert us from the normal routine of our existence, causes us in some way or other to become conscious of that existence.”
—Sir Herbert Read (1893–1968)
“Our two eyes do not make our lot better; one serves us to see the good things, the other the evils of life. A lot of people have the bad habit of closing the first, and very few close the second.”
—Voltaire [François Marie Arouet] (1694–1778)