valve stem

In this groove is a steel roller upon a pin attached to the bell crank operating the main valve stem.

Valve stem guides and valve stems must be machined very accurately to insure correct action.

The amount of clearance allowed depends entirely upon the design of the engine and length of valve stem.

The stem of the handle has at its lower end a crank bend, which engages with the outer end of the valve stem.

The eccentric usually conveys its force through a connecting rod to the valve stem, which moves the valve.