camshaft replacement schedule

[flapjack]

How often is the camshaft replaced? I figure with the exhaust load put on it, and the drive of the fuel pump, magnetos and oil pump, it gets replaced frequently, though not as often as a crankshaft.

 

[glofria]

Cams should never have to be replaced unless they go flat. And that usually happen within the first 20 minutes of running.

Cranks take a pounding though due to the internal combustion.