Final answer:
The volume of the space between the bottom of the valve plate and the top of the piston at the top of the stroke is known as the compression volume. It represents the space filled with compressed gas before the piston starts moving downward.
Step-by-step explanation:
The volume of the space between the bottom of the valve plate and the top of the piston at the top of the stroke is known as the compression volume. This volume represents the space that is filled with compressed gas before the piston starts moving downward. It is the volume that is compressed during the compression stroke of the engine cycle.