Freebase(0.00 / 0 votes)Rate this definition: Imagism was a movement in early 20th-century Anglo-American poetry that favored precision of imagery and clear, sharp language. It has been described as the most influential movement in English poetry since the activity of the Pre-Raphaelites.
The Spring Trigger. A spring trigger is actually a small spring with a threaded end that replaces the hard trigger on specially made index-triggered releases. Because it bends when you pull it, the spring is very difficult to punch. Your only recourse is to keep pulling as you continue to aim at the spot you want to hit.
Understanding what the valve spring is exposed to during normal engine operation is the first step in choosing the correct spring for a given application. At the beginning of its cycle, the valve spring must compress as the valve begins to open. It must stop at maximum lift and then quickly return, allowing the valve to close. The motion must be smooth so the lifter can maintain full contact with the camshaft lobe at all times.