what is the life span of camshats,what sort mileage are they worn?

 

How long is a piece of string ?
It varies enormously depending on so many factors, oil used, engine type, was it run in correctly, etc etc my cossie still has 90,000 mile old cams still perfect condition despite previous owners abuse of the car.
tabetha

 

twice as long in the middle than it is at the ends