Question

Technician A says that valve stem height should be checked and the top of the valve ground, if necessary. Technician B says that an incorrect valve stem height may hold the valve open. Which technician is correct

Answer 1

Answer:

Technician A only

Explanation:

The valve stem height is important as the effects of incorrect valve stem height includes;

1) Side thrust

2) Highly recessed valve

3) Effect on the geometry of the combustion chamber

4) Changes in the volume of the combustion chamber

5) The amount of lifter preload

6) The spring height

7) The amount the valve lifts above the valve seat

8) The valve life span

The valve may stay open after the camshaft lobe is moves past the under the lifter when a valve float occurs at high engine speeds

The valve tips can be grinded as recommended by the manufacturer to correct the the valve stem height.