Hydraulic cam followers

[rah rah 986]

Actually, I have done much research and reading prior to posting my questions here, up to and including you tube videos that show disassembly and cleaning of lifters. (For what it's worth). What I have not found until now (sort of) are answers to some of the questions that I have posed here, which are really a matter of trying to judge whether a lifter is functioning normally, or needs replaced. After sitting for many months, I have lifters that are completely rigid, and lifters that have the ability to be pumped. Nowhere have I found an explanation as to whether one of these conditions, or both are ok. I have tried not to burden this forum with meaningless questions, or questions that have already been answered elsewhere. But, in much of my reading, readers have been forewarned of problematic lifters and the high percentage of these cars that have malfunctioning lifters. So, while I am not a seasoned mechanic, I am a hobbiest with more than average mechanical skills and aptitude who is learning as he goes, and is in the process of reassembling my engine after having had a valve job performed. I am trying to be clear on this lifter issue so that I don't overlook the importance of reassembling this engine with properly working parts. Thanks

[spendy]

rah rah,
I went thru a similar situation. I had some heads rebuilt that were from a working engine that had been out of the car for about a year. When testing the lifters, I found that -all- of the intake lifters felt a bit spongy. Most of the exhaust valves were firm. I know the engine did not have any apparent lifter problems before storage. A possible explanation of this is the orientation of the lifters in the engine. The cup of the intake lifters is tilted downward, while the exhaust lifters are tilted upward. This might explain why the intake lifters leaked down more than the exhaust.

hth

[JFP in PA]

Originally Posted by rah rah 986

Does it then mean that, if a lifter that has been out of a car for an extended period of time and remains rigid, there is a problem with that lifter since it did not drain down and become compressible again?

Yes. Two things will keep these units rigid: They are mechanically jammed and therefore useless; or the oil ports a plugged with debris and are hydraulically jammed.

Some years ago, Jake posted a procedure for "cooking" stuck cam followers in Marvel Mystery Oil to free them up (if they can be), or determine which ones need to get tossed and replaced.

[Gilles]

Originally Posted by JFP in PA

Yes. Two things will keep these units rigid: They are mechanically jammed and therefore useless; or the oil ports a plugged with debris and are hydraulically jammed.

Some years ago, Jake posted a procedure for "cooking" stuck cam followers in Marvel Mystery Oil to free them up (if they can be), or determine which ones need to get tossed and replaced.

JFP,
I also remember seeing a picture posted by BYProdriver where he is 'cooking' the lifters submerged in oil but cannot remember if you are supposed to push them several times while they are submerged in hot oil to 'prime them' and fill them with oil before being installed.

[JFP in PA]

Originally Posted by Gilles

JFP,
I also remember seeing a picture posted by BYProdriver where he is 'cooking' the lifters submerged in oil but cannot remember if you are supposed to push them several times while they are submerged in hot oil to 'prime them' and fill them with oil before being installed.

When being "cooked", the object is to pump them to clean them out. When done this way, the heated oil often comes out completely black and full of crud.

[Gelbster]

So, if they are solid - they need to be replaced IMHO.
*I now believe this may be partially wrong based on dismantling many old M96 lifters. Sometimes the tappet assembly is solid in the bucket because the tappet and the bucket is full of oil.
Proof = Dismantle all the Lifter parts,and carefully reassemble with no oil - the two halves of the tappet move freely. Install the tappet in the bucket WITHOUT the retaining ring - everything still moves freely. Install the retaining ring - ditto. Fill the tappet and the bucket with oil and reassemble completely - Rock Solid to finger pressure.
But remeber ,the lifter will only stay "rock solid"to any degree if the engine oil pressure is sufficient.If the Lifter carrier bores or cam bearings are worn -not so much ? *

[BYprodriver]

Originally Posted by Gilles

JFP,
I also remember seeing a picture posted by BYProdriver where he is 'cooking' the lifters submerged in oil but cannot remember if you are supposed to push them several times while they are submerged in hot oil to 'prime them' and fill them with oil before being installed.

Yes once they are purged of old oil, pump them up in fresh oil prior to install.

[Gelbster]

"Cooking the NEW Lifters"
Now that new Lifters are only $17 instead of $60+++,why clean old ,suspect Lifters?
Some commentators(You Tube) now claim cooking/priming is potentially damaging/unnecessary for new Lifters. I am confused because new lifters come oil-filled and the package is often soaked in leaking oil.So why not replace the lost oil by soaking & cooking?
Is it possible the over-fill the tappet so the dome is so high it causes valve lift/seating problems?
Or would the excess just bleed out harmlessly on start up ? New/old Lifters are different in this respect?
Bleeding Lifters
There are vids showing INA style lifters(ignore the Harley & GM) being vacuum-bled .The author shows the stream of air bubbles rising from the small orifice in the side of the Lifter bucket. But that is just air from the bucket(?) ,not air from the Tappet.The Tappet has a check valve that would prevent any trapped air from escaping? If it did not, the ball/seat would be dirty/defective and it would never hold a full charge of oil in use.It would go soft quickly.So what is the point of bleeding NEW Lifters ? INA does not give an Instruction to do so.
Does 'cooking' bleed air from just the bucket ?How could cooking get air out of a soft Tappet ?
This is a previous version of our INA Lifter to help clarify :
https://www.youtube.com/watch?v=ZCucAyf56Ik
Evaluating new and used lifters
There are credible reports of defective new INA & Porsche Genuine Lifters.see link below
There are references/videos to test rigs that identify defective(leaky) Lifters- new or old.
https://www.youtube.com/watch?v=XvEQ9vIjgy8
The critical leak point is the ball/check valve not the overflow/fill hole in the side of the bucket
https://rennlist.com/forums/996-forum/975059-rebuilding-valve-lifters-can-it-be-done-well.html
INA installation/pumping/priming Instructions
INA do not show any cooking,or priming or filling. The video link below shows a version of the INA procedure.Go to 1.50.
https://www.youtube.com/watch?v=XwTfFesA-yo
To evaluate NEW Lifters I am experimenting with simple rig that others may find helpful.
Use a 12 pt., 1/4 drive, 9mm(11/32") socket plus a 1/4" drive x hex extension. Fit in a drill press.Use a weight on the Press arm to apply a specific amount of pressure on a "solid"(but not jammed) Tappet in a Lifter for several minutes.Measure the Tappet height before/after.
See Post 61 here for a better version:
https://rennlist.com/forums/996-forum/975059-rebuilding-valve-lifters-can-it-be-done-well-4.html
To test your rig - first dismantle an old Lifter and clean(if necessary) leave the Retaining Ring off the Tappet for the test just to make it easier to remove after the test is complete.
Any Tappet that compresses more/much more quickly than the best of your sample is suspect.
Yes it is a crude ,comparative test but it is easy to replicate on many Lifters if you are methodical.
To test the rig further , select a 'soft ' Tappet. Dismantle, clean, refill both the Tappet and bucket with oil.Reassemble. Omit the little spring wire Retaining Ring. It will probably be a leaker and compress too much ,too quickly. Measure the Tappet height before/after to confirm.The amount of oil dribbling out of the fill/weep hole is unimportant.The bucket is just that - a reservoir.
Failure to pump up
One of the most likely failure points of either a New or Used Lifter is the ball seat for the check valve.If you identify this before the engine is reassembled - just clean to remove dirt/swarf.Then retest on your test rig for leakdown.Despite what you read from experts ,the INA Lifter contains 2 springs ,not 1.The spring often shown is inside the tappet and helps it expand.There is also a tiny spring under the ball seat, retained bu a cage.That is where (I think) the problem lies.There are some tight tolerances/clearances there.The slightest defect will cause leakdown.
A 'good' Lifter may fail if it can’t keep it's reservoir(the Bucket of the Lifter) full. If oil pressure is generally low or if oil supply to that part of the Lifter Carrier is obstructed.The Tappet of the oil-starved Lifter may have tested 'good' on the test rig but will tick after a few hours(?) of running.The oil will have been squeezed out of the Tappet into the partially empty reservoir(bucket). The tappet will get air in it and be soft. Until the oil pressure/supply problem is fixed, every Lifter in that location will fail .#4 is particularly vulnerable because of it's position in the oil circulation system(according to credible sources). There are claims that using a (Band-Aid?)10W-50 may help if the problem is slight Lifter Carrier bore wear or similar issues.
The same problem(with the same Lifters) affects BMW also - see M52 and M54 engines.Lots on You Tube
Lifter failure often causes Misfire codes that are misdiagnosed and lead to ineffective parts replacement. The engine cylinder corresponding to the collapsed Lifter(s) may accumulate liquid (un-burnt) gas because of low compression.This liquid gasoline may get purged into the header ?You will then see gas leakage on the header gasket
An unusually loud(but O.K.?) fuel Injector may be confused with lifter tick(see BMW vids). Confirm by interchanging with quieter injector from another location.Much easier than Camshaft removal to chase ticking Lifters!
________________________________________

[Gilles]

Originally Posted by BYprodriver

Yes once they are purged of old oil, pump them up in fresh oil prior to install.

Hello Bill,

When you purge them again in clean oil, does the oil has to be hot well?

Thanks!