What is this knock...

[DslBnz]

Mysterious knock...prompted me to...
Replace all lifters (5 were gone), determine it was not vacuum pump...Noise seems to come from intake runner #2. Other than this, the car runs great! This noise came in and out over a period of two weeks. And now it's terrible. So, what could it be? Cranking the injector lines off on each cylinder makes no difference at all.

Guys, I've checked the timing; it's perfect...There is no excessive blowby...The engine has very strong compression....It just has a terrible knocking noise that is consistent at all rpms.

I will rev the engine in future video clips. So, if it isn't fuel related, it isn't the pump, it isn't the injectors, what could it be?

http://youtube.com/watch?v=JPFZIiT9bdk

I'm generally an optimist. I don't want to even think it's a bottom-end issue. The car does not burn any oil. It runs super. It definitely sounds like it's coming from up top, but the valve-train is super tight, now.