Originally Posted by RobS74
Zetec motors are INTERNALLY ZERO balanced, meaning the factory pulley IS NOT a harmonic dampener of any kind. This means swapping the crank pulley will have NO adverse effects on engine longevity.
I have covered this before.
There are 3 types of pulleys in automotive use, a pulley, a dampener and a balancer. Each has a specific purpose.
A pulley is simply there for a belt to ride on and rotate.
A balancer is used to help balance some component. It offsets torsional flex in an internal shaft generally.
A dampener is used to absorb, limit or isolate harmonic vibration from one component to another.
The zetec has a harmonic dampener.