Hydraulic cam followers

[rah rah 986]

Originally Posted by whitecliffs

Is there anyway to test the hydraulic cam followers once there out of the engine, ive got two sets, one set came from a running engine which was nice and quiet, and another set is untested.

Both set are all solid with no movement, is that the way they should be or should there be some spring movement

I'm hoping some one could respond to the op's question and give some clarity. It does seem that lifters removed from a fresh tear down vary in their movement. some have a fair amount of spring travel, and some are completely ridged with oil pressure. Which is correct? And if reassembling the engine, should the lifters be installed without being pre-pumped with oil-allowing full spring travel, or, should they be pre-pumped with oil making them ridged upon reinstalling?

[JFP in PA]

Originally Posted by rah rah 986

I'm hoping some one could respond to the op's question and give some clarity. It does seem that lifters removed from a fresh tear down vary in their movement. some have a fair amount of spring travel, and some are completely ridged with oil pressure. Which is correct? And if reassembling the engine, should the lifters be installed without being pre-pumped with oil-allowing full spring travel, or, should they be pre-pumped with oil making them ridged upon reinstalling?

Where to begin..........these lifters/cam followers have a "dead end" oil passage design, meaning that once oil gets in, it often cannot get out again, leading to degradation in place, not to mention becoming a receptacle for any debris that is in the oil galley. This results in some lifters becoming solid objects that won't pump.

But now to get to your question, and that of the poster you quoted; you should not be mixing lifter/cam follower locations when using used parts from one engine, or taking them out of one engine and putting them in another. These units take a wear pattern to match that of the cam lobe they have been riding on, moving them to another lobe means they need to re-wear to their new location, which is not a good idea. Both Jake and I commented above on the criticality of the "crown" of the lifter, which promotes proper rotation and reduces wear on both the follower and the cam itself; wearing in the lobes and followers a second time can be very bad news to both.

When disassembling one of these systems, you should be keeping the followers in the correct order to put them back where they came from, or tossing the old units and using all new. In either case, I prefer to hand pump them before installation, and always coat the wear surfaces on the followers and the cam lobes with a good quality flat tappet break in grease to limit excessive wear on start up and break in. Every cam company sells this stuff, so it is easy to find.

Scrounging up used pieces from multiple engines to make one good one is never a good idea, that is how Frankenstein got started, and we know how that worked out.

[rah rah 986]

So is it accurate to say that a properly functioning lifter can be pumped by hand, allowing oil to pass in and out?

Is it normal for the lifter to pump to a state of being solid once it has filled with oil?

And, if after being out of an engine for several months would a healthy lifter be solid, or would it be soft, enabling it to be pumped by hand?

I read posts that refer to lifters "draining down". I interpret that to me that in an idle state, the lifter drains of the oil that had filled it while in operation....the engine running. Is it normal for the lifter to drain down, or should it retain the oil, keeping it rigid?

Sorry about all the questions...I know some seem redundant. But, with my engine apart and ready to reassemble, I am concerned about understanding how to to best evaluate the condition of my lifters. I have picked up bits and pieces of information, but, nothing that really summarizes just what to be looking for in the behavior of a healthy lifter....or, an unhealthy lifter.

Thanks

[JFP in PA]

Originally Posted by rah rah 986

So is it accurate to say that a properly functioning lifter can be pumped by hand, allowing oil to pass in and out?

Is it normal for the lifter to pump to a state of being solid once it has filled with oil?

And, if after being out of an engine for several months would a healthy lifter be solid, or would it be soft, enabling it to be pumped by hand?

I read posts that refer to lifters "draining down". I interpret that to me that in an idle state, the lifter drains of the oil that had filled it while in operation....the engine running. Is it normal for the lifter to drain down, or should it retain the oil, keeping it rigid?

Sorry about all the questions...I know some seem redundant. But, with my engine apart and ready to reassemble, I am concerned about understanding how to to best evaluate the condition of my lifters. I have picked up bits and pieces of information, but, nothing that really summarizes just what to be looking for in the behavior of a healthy lifter....or, an unhealthy lifter.

Thanks

When you pump them up by hand, as they become full, they feel solid, because the oil is not compressible, but this may bleed off over time if left to sit as the oil drains off. Because of their design, the oil has to go in and out thru the same opening.

A healthy unit should pump up a appear to hold pressure by feeling rigid. I never like to put any engine parts in "dry", so giving them a pump up will help on start up.

How are you planning to pre oil the engine before start up?

[Gilles]

Originally Posted by JFP in PA

How are you planning to pre oil the engine before start up?

Hello JFP,

What is the most prsctical way to pre-oil the boxter engine after reassembly?
Do you crank it without the fuse for the oil pump?

Thank you!

[JFP in PA]

Originally Posted by Gilles

Hello JFP,

What is the most prsctical way to pre-oil the boxter engine after reassembly?
Do you crank it without the fuse for the oil pump?

Thank you!

No. We use a small pressure tank (air over oil) filled with break in oil to pressurize the entire engine without having to spin it, sort of like an over sized accusump set up. Once wet, light it off.

[Gilles]

Originally Posted by JFP in PA

No. We use a small pressure tank (air over oil) filled with break in oil to pressurize the entire engine without having to spin it, sort of like an over sized accusump set up. Once wet, light it off.

Cool, so you connect the hose from the pressurized tank to the oil filter housing?

[rah rah 986]

Originally Posted by JFP in PA

When you pump them up by hand, as they become full, they feel solid, because the oil is not compressible, but this may bleed off over time if left to sit as the oil drains off. Because of their design, the oil has to go in and out thru the same opening.

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?

[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.