Tool for attaching valve keys to the valve of the engine

A method of fitting valve keys between a spring retainer and a valve stem of an inlet or exhaust valve on a cylinder head of an internal combustion engine using a tool wherein the holder with internally disposed core is fed axially to the valve, the tool comprising:

• an elongate holder with a longitudinal axis an inner cavity and an end opening through which the upper end of the valve stem can be introduced into a hollow cavity in a holder;
• an elongate core arranged in the hollow cavity in the holder coaxially with the longitudinal axis and having an end region accessible through the end opening;
• and
• at least one transport passage extending in a direction of the longitudinal axis externally on the core and to before the end region of the core for feeding valve keys to a valve,
• wherein the at least one transport passage is laterally delimited at least partially by a guide jaw arranged moveably relative to the holder and at least partially by the elongate core which is fixed immovably in the hollow space in the holder, and
• wherein an elongate recess is provided in the end region of the core coaxially with the longitudinal axis for receiving a substantial upper portion of the valve stem, wherein the recess of the core opens into the end opening and is of a depth greater than or at least equal to an axial spacing between the end and the annular groove of the valve stem so that the end region, upon reception of the upper portion of a valve stem, at least partially covers over the at least one annular groove so that the valve keys can be fed beneath the at least one annular groove to a peripheral surface of a valve stem,
• the method comprising:
• centering the spring retainer around the end opening of the holder by a centering portion and a spring of the valve being compressed;
• axially introducing the upper portion of a valve stem into the recess in the core to such a depth that the core covers over the at least one annular groove;
• and
• feeding, while the at least one annular groove is covered, two valve keys to the peripheral surface of the valve stem through the transport passage below the at least one annular groove.