Hope someone here can give me some good advice.My problem is this:
Several of the 822-16 Comp Cams hydraulic lifters installed in a 440 engine with a 0.525 lift camshaft and double valve springs are very noisy and loose pressure even by hand rotating the engine.
After few turns there is a lot of free play just with a light pressing on rocker arms. The lifters under the pressure of opened valves are almost collapsing overnight.
All this takes to startup with terrible noise ( like a poor diesel Fiat) and I the noise doesn’t disappear until engine very warm, oil pressure is around 80PS with Valvoline 20W 50 VR1 oil.
Thank you in advance
Roberto

20w50 oil is real thick when cold, add in lifters bleeding down and it doesn't surprise me that it takes a while for the noise to go away.

What oil filter are you running? It is a known issue with certain filters that have bad anti-drainback valves for this very issue to occur.

I would do an oil change to a lighter weight oil, 10w30 VR1 would be fine, and a good filter, Wix 51515 is my preferred choice.

Being in Italy though, I do not know what your choices are.

sounds like you may have some of the old Stanadyne tappets. how old is the cam and lifters?

Did you pump the lifters up before install? I know Comp says not to...

They all say not to, for good reason.

What reason is that?

Because it's not needed, it's a good way to bend a pushrod when torquing rockers down, especially in a net lash setup such as the stock rocker setup in most of our cars.

A simple prefill PREOILING before initial fire up is more than adequate to fill the lifters without any issues.

What is a simple prefill?

Preoil the engine where you pull the distributor, put a length of 5/16" hex stock down to the oil pump and turn it CCW for a big block, or CW for a smallblock.

^^ that^^. takes care of the lifters & fills each particular one to the cup height it is at in the firing order & preoils the rest of the eng & you want minimal turning with a new cam breakin. get the dampener slit at TDC #6 compression & preoil then hand turn crank 3/4 turn back CCW & preoil the other bank & cut a strip of paper 17.082" for a ruler (BB). For a SB get it to 90 deg BTDC #1 compression & preoil & alot of of SB's have partial slits at 90 deg or if not then cut a strip of paper 5.694" then continue on around to 20 deg ATDC #6 compression & use the timing tab as a ruler to go from 15 to 20 deg & preoil the other bank. On the lifters, check preload and do Hughes' lifter body clearance check, the "thunk" test

Gotcha, I don't think Comp says anything about that in the instructions though.

That's normal engine building procedures, not necessarily cam swap procedures. If I am just swapping a cam in an already running and broke in engine I don't preoil it at all. I just fire it up.

I see now the comments, thank you. actually i did the break-in of the cam ( XE275XL Comp Cam) as instuctions ( of course I primered with electric drill before 1st startup) and yes it took a little while for the engine to get quite maybe even because of thick 20W-50 oil. The problem was starting the engine the day after, I got a diesel sound again because of 2-3 lifters totally bleeded . Then all this week I've been experienced the same problem and not with the same lifter position, I've been checking and trying more or minus preload until the decision ( a bad one) to install a new set of the same high energy CC lifters (named 822-16). I dont know why but this set of lifters behaved far worse. The noise was louder infact several were almost collapsed or with a big free play under the pressure of a finger.
I wonder if double valve springs ( 924-16 Comp Cams) are the problem or the high lift cam or geometry of valvetrain ( I have pushrod a bit shorter than they should be in order to get a centered line on valve stem)
Sorry I this post is long and boring, problem is where I live, nobody is a specialist ofthese engines and parts eat a lot of time-money.. Thanks anyway

Sorry but just a simple question to whom have far more experience of me:
after engine running, hydraulic lifter are pumped up in the position they are supposed to stay, and this is clear I guess. My question , is it normal under hand rotating of crankshaft that they are bleeding down, even if double or triple valve spring are installed? I've ever thought hydraulic lifters when pumped are like solid ones. Maybe I was wrong..?

Exactly, most people aren't going to do that for a cam swap. A buddy of mine swapped cams, followed comp instructions, and had noisy lifters. We told him to take them out and soak them in oil. He bought another set, followed their instructions, and again had noisy/bleeding down lifters. He took them back out and soaked them and presto no more noise.

OP those 924 valve springs are only about as stiff as most performance singles, and actually weaker than Comp's own 911 single spring (more goofyness from Comp cams). I would advise you to do the same as my buddy, remove the lifters and soak them in oil. You want to make sure that they go back on the same lobes though.

Also, when you install new lifters, you should follow normal new cam break in procedure.

Back to prefilling, again, not recommended for any reason.

To the OP, what brand oil filter are your running?

Well the comp cams method didn't work for the OP twice now, so maybe he wants to try something new (that people have done since the invention of the hydraulic lifter). For what its worth I've never heard of someone bending a pushrod because their lifters were pumped up. Just offering another opinion for the OP.

I have the same problem with the same cam and lifters in a 440
everything you said is happening to me exactly
I am going to put the pro magnums, in

the lifters are JUNK had 2 sets and the same issue go with solid lifters and never look back

hi Roberto, I am going to ask a QUESTION, What is the history on the motor, specifically who installed the camshaft and lifters, and WHEN ?
I have had a few experiences where REPUTABLE builders installed/ substituted Cheap lifters to save a few bucks on the "build" We have had ZERO issues with comp cams lifters PERIOD!! So, a bit of history may help identify the root cause.