Which element keeps the upper valve spring retainer attached to the top of the valve stem?

• A. Valve spring keepers
• B. Valve spring retainer
• C. Valve Seat Insert
• D. Valve guide

Answer: (A)

Locking the valve spring assembly to the valve stem is done by the valve spring keepers. These small locking pieces fit into grooves on the valve stem and engage with the edges of the valve spring retainer, securing the retainer to the stem so the spring and retainer move with the valve as it oscillates. Without the keepers, the retainer could lift off the stem during operation. The other parts have different roles: the valve spring retainer provides the seat for the spring, the valve seat insert is the sealing surface in the head, and the valve guide keeps the valve aligned as it moves.