The 1/4-1/2”I'd add that counting and documenting the number of turns when loosening til clacking and tightening to quiet and everything in between was immensely useful in helping me "see" mentally exactly what was going on in the big picture. I'd just turn 1/8 turn, still no clacking, another
Appreciate Everything mentionedOP
Your motor does Not have poly locks --- yours has plain-jane, common OE interferance nuts --- and No, they are Not something found at a local hardware store.
here is a poly lock image
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as someone else has already advised, OE chevy sbc & BBC PRs are indeed hollow --- their formed ends are usually rather thin and Do wear --- they can get very Hot, especially Hot when abused and become weakened, --- Their Ends can & Do fracture and ends can & Do collapse in onto themselves --- inspection of this is SOP.
Same goes for the PR "pocket" that's stamped into OE rocker arms --- that pocket can & does get Hot and weakened and can & Do fracture and then break out.
Everything has already been addressed and observed
Another words Looked over for them failure points . The pr’s are not collapsed in they are all flowing oil right thru the rods and flowing over the rocker arms at idle with valve covers off - not bent - the rockers pockets all look good.
The poly lock statement is my bad , I now know the difference between the two types , And yea I got a set of 8 interface nuts for 99c each at AutoZone they have a slightly crimped end.
I’ve updated ‘my new findings observations and fixes so far prior to your reply here . I believe it is an intermittent lifter issue topped with improper lash and pre- load. I am going to take care of that adjustment today and put some miles on it and see if all stays good . I think all of this kind of happened after I did the “Oil cooler) and line delete which I always do on my 350s with the melling MFA350 part which is a good thing and preventative maintenance for the common failing leaky lines , but the oil change at that time seemed to trigger the issue if it is indeed a sticky / failing lifter . The lifters or the one or two might be working and sticking collapsing at that point mimicking a loose rocker arm hence the chatter ‘ ~ if I am guessing right. And then when they wanna Unstick it could be causing
Too much preload seeing as I have been re- adjusting lash on a sticky lifter . Seems to be a tug of war fix and failure thing going on.
I might need to run some type of cleaner or treatment maybe change oil again . It was black as night when I bought the truck .When the first noise started I immediately noticed on idle start up the oil psi went from 45-50 idle too 20-30 at idle
Might I add that the truck has 176k it was an old farmers truck / may have had conventional in it for the last 30 years , some folks stick by it. I did add Mobil 1 full syn This truck had and still has 60psi on cold start and 45-55 at normal speeds . So I dunno seems like a lifter thing to me / I hope just sticking from sludge. I put a good 100-200 miles on the truck before the noise happen , maybe the syn detergents loosened grime
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