The noise was likely coming from that nasty tensioner wheel. Honda still sells them: get theirs if you can. While at it, maybe also get their roller arm unit as well...the pivot pin and bushing in some aftermarket versions of these (sold from 2006 thru 2010) had nasty burrs on them that prevented the arm from swinging easily to follow the cam chain during high-RPM excursions. This made the chain go into a 'standing wave' pattern that then battered the lower roller, tearing chunks out of it prematurely. Not everyone who bought these parts back then noticed that the arm was not swinging freely during installation, so many of them failed in less than 5000 miles, sometimes because of poor tensioner setting. They ended up being 'recalled' by the many aftermarket vendors, and Honda stepped back up to make the properly-machined versions again. If installing one of those aftermarket ones, just make sure to sand off the burrs in the punch-steel roller arm so the pivot moves freely when installed.
There is a lot in this paragraph. "standing wave" of timing chain make sense giving the damage in the cam chain valley and head. I figured it had to to with the tensioner wheel that is clearly compromised but I wan't sure how it could wavier off course that much. Do the aftermarket wheels, like CYCLEX's which seems like a design improvement, create more chain noise thus continuing to recommend OEM Honda?
I haven't had a chance to try Ken's fancy cam chain tensioner, but I am glad there are some options out there nowadays. For a while there was someone in Europe making nylon tensioner wheels for both parts. For racing apps, I am sure this is a good idea, as it damps the tendency for the chain to form standing waves at certain RPMs, and prevents the chain from chunking away the rubber when it makes these odd vibes at high RPM. For touring though, I'm not yet sold on it. Even touring at 80 MPH is midrange RPM in this engine (and on mine with the 19T countersprocket Ken makes, it is just 4400 RPM!).
