Figure 3. Intake Port, Exhaust Port and In-cylinder Pressures with Poor Tuning. The timing of the arrival of the negative wave at the back (port) side of the exhaust valve is determined by the engine RPM, the speed of sound in the pipe and the distance from the valve to the relevant change in area.
Fault (geology) In geology, a fault is a planar fracture or discontinuity in a volume of rock, across which there has been significant displacement as a result of rock-mass movement.
anything that fails, that is wanting, or that impairs excellence; a failing; a defect; a blemish. Fault (noun). a moral failing; a defect or dereliction from duty; a deviation from propriety; an offense less serious than a crime.