multiple NAV engines in my Library folder

Norton 360 for Mac
1

I have multiple NAV engines in my Library/Application Support folder. Is that necessary?

 

I am running Norton AntiVirus Version 11.1.2 (17). My computer is a Mac G4 with the old PPC processor. My system is OS 10.5.8.

 

When I look in Library/Application Support/Symantec/AntiVirus, I see three engines, each taking up over 400 MBs of space.

One engine is simply titled "Engine". Another engine is titled "Engine20130308" and another engine is titled "Engine20130312".

 

What can I do to free up some of that space? Can I simply delete the older engines, or is it more complicated than that?

 

 

Thanks for your advice      -John