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:
“Humanity has passed through a long history of one-sidedness and of a social condition that has always contained the potential of destruction, despite its creative achievements in technology. The great project of our time must be to open the other eye: to see all-sidedly and wholly, to heal and transcend the cleavage between humanity and nature that came with early wisdom.”
—Murray Bookchin (b. 1941)
“The more the development of late capitalism renders obsolete or at least suspect the real possibilities of self, self- fulfillment and actualization, the more they are emphasized as if they could spring to life through an act of will alone.”
—Richard Dean Rosen (b. 1949)
“Fear can supplant our real problems only to the extent—unwilling either to assimilate or to exhaust it—we perpetuate it within ourselves like a temptation and enthrone it at the very heart of our solitude.”
—E.M. Cioran (b. 1911)
“And if the stage-dark head rehearse
The fifth act of the closing night,
Why, cut it off, piece after piece,
And throw the tough cortex away....”
—Allen Tate (1899–1979)