hydraulic lifters acting weird

[Marx3]

Hi, I need people's opinion on something...
I just rebuilt a 1978 L78 Pontiac 400. Put in a new cam ( crower 60240 ) and new lifters.
I just re-adjusted all the lifters after cam break-in.
Adjusted to 1/2 turn past zero lash. When the lifters were off the cam lobe I tried pushing on the rockers with a big screwdriver. Each rocker would press into the lifter without any effort. I could make the pushrod go down into the lifter without even laying any weight on the screwdriver... I am thinking these lifters can't possibly transfer the movement of the cam lobes, can they? I am doing this right after the engine is  turned off...
On top of this 3 of the lifters felt solid. I could not make the pushrod on these 3 go down into the lifter at all. Like they were jammed.
Lifters are Clevite, dont remember the exact model, but I got them cheap on Rockauto.com.

If I tell you that the engine is a dog, would you say these lifters could be to blame?

[73ss]

Kinda normal, especially with low buck lifters. I had the same thing on my 454 chevy some years ago. You could press the lifter plunger down with little effort as you describe. It would make some valvetrain noise from time to time on start-up. As soon as the engine fires they should pump up.

I swapped out that cam & lifters and went with the comp "Hi-rev" lifters. They have a snap ring instead of the wire clip. I noticed they were difficult to push down when setting lash. Anyway I have had zero start up valvetrain noise with these. Even after sitting for months at a time.

[Marx3]

I guess this is normal with cheap lifters then...?
I shouldn't have bought the ones at 1.5$ each, but the ones at 5$ each instead...

[Jeff K]

Did you take each lifter apart and clean and inspect before installation? I also pitch the cheap hair pins and install circle-clips....

On some lifters, the plunger will go right in without oil pressure and an open check valve, it's a different story when the motor is running and the check valves are opening and closing...

That's a nice cam for that combo, a local has that cam in a lo comp 400 and it's nice....

[Cliff Ruggles]

One full turn past zero lash will put the plunger in the middle of it's travel.  1/2 past zero can result in some noise depending on which lifters you have, at least from what I've seen here.....Cliff

[KJMason]

What adjustment have you found best for original Rhoads lifter adjustment Cliff?

[Marx3]

woops, hadn't seen these new replies!

A guy I know who have rebuilt many engines over the years suggested the lifters weren't getting suficient oil pressure.
I then realised I had NOT cleaned out the darn feed channels for the lifters.
The rest of the block and the crank was cleaned out very thouroughly, and I found lots of thick old oil and such. I am 99% certain the problem is related to these channels not being clean.
I am pulling the engine in the next couple of weeks and taking it apart to clean it out properly.
I will put them at 1 full turn past zero then...

Can't wait to see this cam's potential! I had it suggested by a certain Pontiac-guru I know... ;-) ;-) ;-)