When you open the config file you will find something like this:
# Killcam Config File
# How long the killcam will be active (In ticks)
# 20 ticks = 1 second
# Example: 100 ticks = 5 seconds
When you edit TimeInTicks, the killcam will be active for however long you made TimeInTicks.
Please remember, TimeInTicks is the number of ticks you want the killcam to wait before it
turns off. For most servers, 20 Ticks will equal 1 second.