Tappet clearance question

[westcoastkevin]

Yes I have replaced the head just a few weeks ago.. I was chasing this loud Tappet when I discovered the old head had a crack in it..
I did roll each pushrods on a glass surface, and all of them were straight.
I dont think there is a hairline crack because I replaced the noisy pushrods with a brand new one, and no change. I then swapped the old one back in.
I suspect that this might be caused by two things. A bit of slop in the rocker arm bushings, coupled with slightly worn rocker arm surfaces where they meet the valve, and finally, the fact that I've been leaving them a bit wide. I've actually been adjusting them so I can just fit a .012" feeler in there, but it's a bit tight, so I think I just am going to buy the whole rocker arm assembly from turner, and readjust everything to the proper .010" if that doesn't help, then I'm living with it as is.

It seems a little excessive to buy a whole rocker assy. If the noise goes away at 0.009"/0010" when hot. set it like that and forget about it for six months and check it again.

[Alk-3]

It seems a little excessive to buy a whole rocker assy. If the noise goes away at 0.009"/0010" when hot. set it like that and forget about it for six months and check it again.

Yes, I will check the settings once again, and tighten them up a bit before I buy a new rocker assembly, but at this point I'm not expecting any real miracles. I don't mind spending a bit of money for the ease of the job rather than having the old one reconditioned. I have to have the truck on the road, as it's my only mode of transport, so sending the rocker assembly off for reconditioning is not worth the $150 for a new one..

[Alk-3]

Oops. Double post.

[Billy5]

Good morning, not to add confusion to the mix but..lol. The advice I have been given for adjusting the valves is to adjust them so .09 slips through easily, .10 slips through firmly and .11 will not go through at all. Also, I have read that the screws holding the info plate on the valve cover can sometimes make the noise too. I have a tick as well, but my thinking is .10 hot or cold, seems like they wanted some play in there.

[Alk-3]

Okay, I've adjusted everything about four hundred times now, with no luck. I got a whole new rocker shaft and rocker arms from turner, and assembled it carefully, and reinstalled everything.. Still the same tapping.. Uhhg.
So here is what I'm now thinking: the tapping is intermittent, and comes on every couple of seconds, and lasts a couple of seconds. I'm starting to wonder if my number four valve has a slightly out of round cam follower. I've played with things while the engine is running, and slipping feeler gauges under the rocker arm quiets things down completely, but it seems if I try to do this durring the noisy few seconds, it's a bit looser than when it sounds normal. I've replaced the whole head, so new vales, guides etc.. I've now also replaced the whole rocker arm assembly, and I have swapped in a new pushrod, all with no effect on the tapping noise.
For arguments sake, couldn't I just adjust it down to a few thousandths or untill it stops making the noise and leave it at that? Is the specified clearance just an arbitrary number that will allow the valve to fully seat, so really any amount of clearance is sufficient, or does the clearance effectively determin the duration the valve is seated? I'm trying to learn just how this stuff actually is designed to work, and why, in order to determine the safe limitations in actual practice.
On the other hand, does it hurt to have to rocker set for slightly too much clearance.. Say, .013" or .014"?

[TeriAnn]

The little adjustment spec plate on the valve cover is held on by 2 screws. At least one of the screws is directly over a rocker arm and with a slightly thin valve cover gasket, rocker arms have been known to contact the end of the screw.

Try removing the screws and seeing if the tapping goes away. If that's the case the cure is to put the screws back on then grind off a little from the bottom end of the screws.