Advice on knocking sound with video clip

[crazyone64]

Hi,
Could i get your opinion on what this knocking sound might be.
2003 Mach1, v8 dohc, around 85000km / 52000 miles.
It's most present at 10-13 seconds in the video.


View: https://youtu.be/1F8YI8fY47U

 

[Deleted member 38176]

Does it only occur on start-up? Does it increase with revs? Are you able to decipher exactly where the sound is coming from (left side, right side, upper, lower)?