Rocker arms loosening 93 5.7 tbi

[A97obs]

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

The 1/4-1/2”

OP
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

You must be registered for see images attach

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.

Appreciate Everything mentioned
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

 

[scott2093]

The 1/4-1/2”

What I was getting at is , for example, I was surprised to see it took 1.5 turns to get to just past zero lash on some lifters (clacking), but 1 turn on others.

After I blindly did my first running adjustment, when I returned with the mindset to document everything, they were all over the place in the amount it took to get to just past zero lash. My theory is that I rushed through initially it and some weren't actually at zero lash because they would actually get quiet if I waited 10 seconds.

Anyway, after getting used to documenting everything, I saw that my lifters originally had over 1.5 turns past zero lash. Why? I'm not sure. I was a crate motor and I don't know what lifters were installed.
Basically, when you do another adjustment, you should see that it takes exactly whatever you set your preload to (1/4-1/2 turn) plus a hair, to get them to clack....
Again, my surprise was when that didn't happen after my first running adjustment.
I had everything set for 1/2 turn past zero lash but, when I went to loosen them again, it took way more turns on some to get them to start talking....

 

[A97obs]

What I was getting at is , for example, I was surprised to see it took 1.5 turns to get to just past zero lash on some lifters (clacking), but 1 turn on others.

After I blindly did my first running adjustment, when I returned with the mindset to document everything, they were all over the place in the amount it took to get to just past zero lash. My theory is that I rushed through initially it and some weren't actually at zero lash because they would actually get quiet if I waited 10 seconds.

Anyway, after getting used to documenting everything, I saw that my lifters originally had over 1.5 turns past zero lash. Why? I'm not sure. I was a crate motor and I don't know what lifters were installed.
Basically, when you do another adjustment, you should see that it takes exactly whatever you set your preload to (1/4-1/2 turn) plus a hair, to get them to clack....
Again, my surprise was when that didn't happen after my first running adjustment.
I had everything set for 1/2 turn past zero lash but, when I went to loosen them again, it took way more turns on some to get them to start talking....

I just wanna know one thing’
Visually on a 3/8 ratchet handle once I get to zero lash ( No clatter)
1/4-1/2 turn is taking the ratchet handle end setting it up at 12noon and tighten to 3pm that is technically 1/4” turn ?

Or 12pm to 6pm that’s 1/2” turn
that is the “EXTRA” preload only after you get the chatter to go away

 

[Road Trip]

I just wanna know one thing’
Visually on a 3/8 ratchet handle once I get to zero lash ( No clatter)
1/4-1/2 turn is taking the ratchet handle end setting it up at 12noon and tighten to 3pm that is technically 1/4” turn ?

Or 12pm to 6pm that’s 1/2” turn
that is the “EXTRA” preload only after you get the chatter to go away

You got it right.

I do the noon to 3 o'clock twice on each self-locking nut and call
the preload setting good.

By going through this process methodically you will have set your
adjustable valvetrain SBC preload more precisely than 99% of the ones
that have been ever worked on. Take pride in your precision. :0)

 

[scott2093]

Count the wratchet clicks...lol

 

[A97obs]

Count the wratchet clicks...lol

lol what’s the magic number

 

[A97obs]

do the noon to 3 o'clock twice on each self-locking nut and call
the preload setting good.

Learning curve here .. def understanding more and more .

Does the 12-3 preload get done with the engine running at idle as you would’ do to resolve the clatter .
Or… once the clatter is gone do you prefer to turn the engine off and run that pre load on that very rocker arm

 

[A97obs]

Seems like once the chatter is gone, it would be easier to kill the engine right then in there and then do the preload with no mechanical movement?

Ease of hot oil over flowing on exhaust , more of an accurate preload that’s why I asked because I assume that part is done with the engine off. Once chatter is gone from the initial zero lash
Or will the lifters bleed down some and throw everything off if you do the pre load with engine off

 

[A97obs]

It might sound ignorant, but it just occurred to me. Preload has to do with keeping the lash in place for lifter bleed down essentially a dry startup?

 

[A97obs]

You got it right.

I do the noon to 3 o'clock twice on each self-locking nut and call
the preload setting good.

By going through this process methodically you will have set your
adjustable SBC preload more precisely than 99% of the ones that
have been ever worked on. Take pride in your precision. :0)

I have one more question it just makes sense to ask. Do you want to set the preload on all eight rockers in line at once or do you want to do the preload on each cylinder with the one cylinder time or one valve at a time .
Meaning if I get the zero lash on the last cylinder exhaust side do I find the zero lash on the intake side of that cylinder( then shut the truck off) and run the pre load 1/2 turn on that cylinder only !
Then repeat on next cylinder ?
I just wanted to make sure setting preload on a cylinder and then running the vehicle to check the lash on the remaining cylinders doesn’t throw everything off having preload on some and not on others while the engines running