Post
by Snakeoil » Sat Mar 17, 2012 8:12 pm
I tend to think it is just lash from wear. Probably an internal chain. If you call it a tap and not a knock then I don't think it is worn bearings or piston slap. Piston slap and worn bearings tend to be more of a knock than a tap in my experience.
I had an engine I got for free that has such a loose oil filter chain that it jumped off the sprocket and chewed up a few things. So you may want to take a look at that chain. You can follow the adjustment procedure for the cam chain.
I think it was LM who said that the primary tensioner is really more of a follower and does not really act like your typical primary tensioner. When I took the side cover off my engine, I could see where the primary had at one time been slapping against the top of the case. I measured the slack in my primary and it was beyond the recommended limit. I got lucky and found a NOS chain. Not many of those around.
Not sure if you would gain anything if you put a stronger spring on the tensioner. LM might have some input on that. I realize that a stretched primary has also had it's pitch changed a bit. But if you cannot get a new one, keeping the one you have from chewing up the cases is probably a decent compromise.
regards,
Rob
