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Hydraulic lifter install question

Started by Mrbill426, August 26, 2021, 06:44:19 PM

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Mrbill426

I have a  question about (new) flat tappet hydraulic lifter installs, with a new cam and stock non-adjustable arms....  In the past I have just lubed them up externally, put them, and and ran them.  I have also pre-pumped them up (full) with oil to avoid that initial clatter.
Now I am reading about pre-load specs but they all seem to be with adjustable rockers.  Does it really matter either way with non-adjustables?  Not a high lift cam @ under .50" .
It is a 340 if it matters.

:wrenching:

Chryco Psycho

It depends on the machine work & is worth checking for sure , you need to measure the distance the piston inside the lifter is depressed when the rocker gear is tighten up , the only adjustment is the pushrod length .

Mrbill426

@Chryco Psycho...  So with the lifters dry then it would be checked with the lifter on the heel of the cam since any other position would of course depress the plunger to the bottom because the valve springs certainly won't compress.... Right?  Then how much preload (or play) should there be?
Thanks


Quote from: Chryco Psycho on August 26, 2021, 08:41:59 PM
It depends on the machine work & is worth checking for sure , you need to measure the distance the piston inside the lifter is depressed when the rocker gear is tighten up , the only adjustment is the pushrod length .


Chryco Psycho

Correct you need to be on the low point on the lobe to check , less depression is better too limit pump up , I believe the lifter travel is about .060 , best to be in the .020 - .030 range , there should never be play !

Mrbill426

@Chryco Psycho ok I will try that.  By "play" I meant how far down the barrel the plunger should be, or the distance from the clip to the plunger with the lifter on the heel.  Right, the pushrod should have no play up and down.
What you mean?




Quote from: Chryco Psycho on August 26, 2021, 09:03:41 PM
Correct you need to be on the low point on the lobe to check , less depression is better too limit pump up , I believe the lifter travel is about .060 , best to be in the .020 - .030 range , there should never be play !

Chryco Psycho

You have it right .020 below the clip , preloaded , no play

Mrbill426

@Chryco Psycho  this afternoon I put a dial indicator above the the rod pocket (a bit quirky) of the rocker arm, and with lifter on the base circle I torque down the shaft and got a reading that says the plunger is going down about .045" into the bore.... From that point I can push the rocker sending the plunger an additional .100+"... More like .140" actually, meaning I came up with around .200" total plunger (to the bottom) travel.




Quote from: Chryco Psycho on August 27, 2021, 10:42:28 PM
You have it right .020 below the clip , preloaded , no play


Filthy Filbert

Sounds about right.   Take a lifter apart and you'll see how much travel is available.   1/4" sounds about right on brand new empty lifters. 

Once you have oil pressure, that cavity will fill up and make the lifter act 'solid'

chargerdon

Just an FYI... 

My Lunati camshaft came with instructions for measuring the pre-load.   

It states to lay a flat edge on the valve cover surface of the head and to scribe a line on the pushrods.   Then to remove the rocker assembly BUT NOT the pushrods and that they will rise as the assembly is removed due to the oil pressure in the pushrod being relieved,  and scribe a second line.   The difference between the two marks on each pushrod is the amount of the preload.   They say preload of .020 to .060 is recommended. 




Mrbill426

@chargerdon  I will try that method today.  I don't have one of those push rod checkers and that sounds more accurate than a dial indicator on a somewhat wobbly rocker arm. 

Thanks


Quote from: chargerdon on August 28, 2021, 07:24:31 AM
Just an FYI... 

My Lunati camshaft came with instructions for measuring the pre-load.   

It states to lay a flat edge on the valve cover surface of the head and to scribe a line on the pushrods.   Then to remove the rocker assembly BUT NOT the pushrods and that they will rise as the assembly is removed due to the oil pressure in the pushrod being relieved,  and scribe a second line.   The difference between the two marks on each pushrod is the amount of the preload.   They say preload of .020 to .060 is recommended.

Chryco Psycho



Mrbill426

@Chryco Psycho good I am going to go with it...

Tell me, or someone tell me... if I pre-lube this engine with a drill and pre-lube shaft should the empty lifters fill up a bit?  Otherwise it will be spinning over with valves barely opening

Thanks!

Quote from: Chryco Psycho on August 28, 2021, 08:01:21 PM
At .045 sounds right on .

Chryco Psycho

Preoiling will get some oil into the lifters but the valve will still open & the engine will run for the 10 -15 seconds or so it takes to get oil there .

Filthy Filbert

pre-lubing with a drill will fill voids with oil, but not create any real oil pressure.    The drill might make 5-10 psi of oil pressure (I've never put a mechanical gauge on during pre-lube. I just spin it till I see oil flowing out the rocker shafts.)  the real oil pressure will come from the oil pump when the engine is at 1000 rpm or better.