19. In a cylinder block, the opening that the valve head rests in is called the valve
A. margin. C. stem.
B. seat. D. guide.
seat
a what is a set of fitted parts designed to complet a function
The opening in a cylinder block where the valve head rests is called the valve seat. To arrive at this answer, we can analyze each of the options given:
A. Margin: The margin refers to the edge or border of the valve head, it is not related to the opening in the cylinder block.
B. Seat: The valve seat is the correct answer. This is the surface within the cylinder block where the valve head makes contact.
C. Stem: The stem is the long, slender portion of the valve that connects the head to the mechanism controlling its movement. It is not related to the opening in the cylinder block.
D. Guide: The valve guide is a component that provides guidance and support to the valve stem, ensuring it moves in a straight path. It is not related to the opening in the cylinder block.
Therefore, the correct answer is B. Seat— the opening that the valve head rests in is called the valve seat.