Electromagnetic valve actuator and valve guide having reduced temperature sensitivity

A valve actuation system for a multiple cylinder internal combustion engine, the system comprising:

• an electromagnetic valve actuator having an armature disposed between upper and lower electromagnets with an armature stem extending through only the lower electromagnet;
• a bushing disposed within the lower electromagnet with the armature stem passing therethrough, the bushing having a first clearance relative to the armature stem near at least each end of the bushing and a second, larger clearance relative to the armature stem in at least a middle portion of the bushing;
• and
• a valve guide for guiding an engine valve stem actuated by the armature stem, the valve guide having a lower guide with a stepped outer diameter that cooperates with a counter-bored hole in a cylinder head to provide a positive stop during installation, and an upper guide having one end in contact with a contacting end of the lower guide, the upper and lower guides each having a first clearance relative to the valve stem at one end, and a second, larger clearance relative to the valve stem at each contacting end.