From what I just read, all of your lifters/valves are 1/4 turn open. You squished them down past their hydraulic lift and they are now solid lifters.
Open them all back up and adjust properly without the engine running.
I respectfully disagree, because if all the valves were cracked off the seat this would
prevent the engine from starting up, much less a smooth idle.
When adjusting a hydraulic lifter, when you first adjust for no clacking,
you are now at the *top* of the hydraulic adjustment travel that the
inner plunger has to work with. And on the GM engine assembly line
(using factory lifters featuring factory machining & tolerances) they are
supposedly set at 1 full turn, putting the plunger
midway in the travel.
(ie: OEM lifters have 2 full turns worth of adjustment available.)
The problem that I and others have run into is that aftermarket hydraulic lifters
will sometimes bottom out with only 3/4 of a turn preload. This is one of those
times when I deviate from the FSM because things have changed with what
gets delivered to the doorstep for me to use while trying to keep these engines
running in the 24+ years since the General originally put ink to paper.
So that's the short version of why I recommend that all 16 lifters are set to just quiet,
and then afterwards a 1/4-1/2 turn of preload is added to the 'just quiet' adjustment point.
I've done this for years & years, and it's the only way I've found that puts a long
term fix on a SBC hydraulic lifter adjustment.
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For what's it worth, I used to set the hydraulic lifter preload cold,
twirling the pushrods feeling for resistance while at the same time watching
for the lifter internals to just come off the lock ring. After making sure
that the lifters were pumped up prior to placing them in the bores.
And when you used to get all 16 lifters with the same leakdown rates,
they would all act the same and even I could get it pretty close to right
using the prescribed method.
But now when you purchase 16 hydraulic lifters and pump them all up,
then most of them will act the same, but in some the plunger can be
depressed much easier than the others, (due to looser internal mfg clearances)
...and this is why it's so hard for me to do these by feel anymore.
Given all this, my #1 preference is setting the lash on solid lifters. So
much simpler, so many less variables.
My #2 preference is to set the hydraulic lifters with a running preload
adjustment after a best-effort cold adjustment during assembly.
And the rest of the methods? Well, I just don't do it anymore. Instead, I
just excuse myself and resume my spot on the bench. But if asked I'll
jump back in later if the engine is clattery (too loose) and/or exhibits a
rough idle. (Too tight.)
This is just one more data point to add to the mix. No doubt that there are others
who can deliver the same/even better hydraulic valvetrain adjustment using the
cold preload method. Maybe if they can share their process then I can do it too.
No doubt less messy to boot. :0)
Cheers --
PS: Here's a good article from Chevyhardcore about lifter state of the art. Will cure insomnia: (
Detailed Lifter Tour de Force)
