So after listening to the engine knock sound from here:http://www.youtube.com/watch?v=GGJZ6...eature=related

I am fairly certain that this is what is happening with my engine... This is a ls-v that was tuned... But under load, ie when i accelerate, i hear this marble-going-down-a-metallic-tube or rattling sound from my motor. When idling or just cruising, nothing... runs smooth.
I run 93 or 91 when that's the only available gas... oil is good...

I guess this video explains it more: http://www.youtube.com/watch?v=GoK4A...eature=related

So What are the consequences of this on the motor? can I damage anything permanently? I've had this noise since January of this year and have drove from FL to ME to MA...
Just trying to fix the problem and keep my motor running as long as possible...

Sorry if newbie question...
thanks

 

Is the ignition timing set to spec?

 

yes the timing is set to spec as in the cams where set to spec... i have not touched the dizzy at all, but cams and timing is good...