Hey guys, I just rebuilt my 355 and its running great except for a rocker knock on the right side. I've re-adjusted it probably ten times and know exactly where the knock is coming from but I always adjust it until its quiet, then put the valve cover back on and then it starts knocking again a few minutes later. Do I just need to tighten it down a little more after it stops knocking or is something wrong? Thanks for the help.

Ed

I assume its hydraulic, in which case, turn it down till it stops clacking, then another 1/2 turn. Should solve your problem :)

some lifters will not stay pumped due to some trash inside them. Sometimes it will work itself out , but not always.

ok, so i'll tighten them down a little more than it was and keep running it and hopefully that will solve my problem. i really don't want to go pulling things apart again.

bad lobe?

Had problems like this on my 70 over the years. With the original aluminum valve covers a rocker will hit on the inside of the cover, check for a wear spot if you have these covers. Also have had problems with the top of the valve wearing a bit on one side, the rocker runs a little crooked and this creates clearance, valve will tap on that one rocker. Pull the rocker and check the tip of the valve, the rocker stud for a groove, and the rocker pivot ball for unusual wear. Otherwise, probably a bad lifter.

bad lobe?
+2 may be everytime you tighten it down, its just knocking that much more off the lobe. Been there..

Nut backing off? Or cam going flat.

If something is going bad i'd think I would have noticed it before the rebuild, but maybe you're right. I'll give it a few days and really tighten it down and see what happens. If its a bad lobe what am I looking at for parts $ and labor time?

Possibly the stud pulling out?
Take a look at all the studs/rocker nuts next time you have the valve cover off. Do you have about the same engagement on all of them? Are they all even? If not, then you will have a better idea where to look. If they are all even then most likely it's the nut backing off. Did you use new ones, or reuse the old ones?

If something is going bad i'd think I would have noticed it before the rebuild, but maybe you're right. I'll give it a few days and really tighten it down and see what happens. If its a bad lobe what am I looking at for parts $ and labor time?

You'll need a new cam. Farm it out? Prob cost you $750 or so.