Aspire HLAs vs valve lift

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I'm trying to rebuild a couple hlas for my car, I'd like to get a whole fresh set in there. I've got 10-15 hlas here in front of me, and I've messed with 7 so far. I can't get any of them to hold solid fully extended, 5 of them will push in halfway and no more, two are completely collapsable...this is after pushing the check valve in, collapsing the lifter to squeeze out old oil, then holding them in a cup of 40wt and collapsing them over and over and over until they build pressure and no more old oil comes out.


I'm assuming that they are supposed to be able to collapse halfway to keep the oil flowing through, but I'm not sure. These things sit right on top of the valve stem and are directly resposible for the valve opening fully, so I need to know if I'm right in assuming this is how they work, or if these are all junk? They have anywhere from 98k-175k miles on them. Most were stuck solid between halfway and fully extended, a couple were completely collapsed and wouldn't open at all without some carb cleaner, but those ones are the ones that hold the furthest open now.

[nitrofarm]

Zoom I recently purchased new ones for a top end rebuild. And I thought I would be "smart" and pre load them with oil. Well long story short you have to be very carefull other wise you can "cock" the spring that is inside of them. And its a bugger to try to get it straight. Finally after @ 1 hr of putzin around I got them all preloaded and solid. But I still have my doubts on one. If when I start my engine & hear it ticking at least I'll now why & where to look.So with that being said it is my observation that they should all be rock hard & stay that way. If not,my guess would be the o ring isnt sealing or the spring that is suppossed to sit under the check ball is weak or even worse "cocked". Hope this helps-

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Is that with the hlas in the rocker or out?

I can't find a way to separate the hla, is it possible to do that? It would have to be if they have a spring and ball inside..

[nitrofarm]

Thats with them on the bench. Are they servicable? I didnt really look that close to see if you can open them up. My guess is they are pressed together with the internals properly installed????

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Ah, yea..I just took one apart Haha, they aren't meant to be though! I ended up having to break off the top shell. It's pressed onto a lip. I'll see if I can get a pic uploaded later. There's 2 springs inside!

These have to be able to compress as the valve opens, otherwise they wouldn't be built to pump oil.

My main question was wether actual valve lift is measured with the lifter collapsed, or uncompressed, but I did a bad job of conveying it in the original post.

[nitrofarm]

Ah, yea..I just took one apart Haha, they aren't meant to be though! I ended up having to break off the top shell. It's pressed onto a lip. I'll see if I can get a pic uploaded later. There's 2 springs inside!

These have to be able to compress as the valve opens, otherwise they wouldn't be built to pump oil.

My main question was wether actual valve lift is measured with the lifter collapsed, or uncompressed, but I did a bad job of conveying it in the original post.

Oh thats easy valve lift is always measured with the lifter solid....

[blkfordsedan]

Valve lift depends on the height of the cam lobe and the rocker ratio. The HLA'S have no effect, as long as they're solid and don't compress (like Nitro said) and they take up the lash. They are fed pressurized oil through the check ball, so once they see oil pressure, they should fill up with just enough oil to take up the lash when the cam is on the base circle. That way, as soon as the rocker arm starts up the ramp of the cam lobe the valve begins to open. If the HLA'S or lifter is spongy or springy then the lift and duration at the valve is reduced. You should bleed the oil out of the HLAs when you install them and let the oil pressure pump them up to the exact height required to just remove the lash from the system. If you install them already pumped up, they may already have too much oil in them and not allow the valve to completely close. If they are functioning correctly, they will not bleed of the excess oil.

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They compress halfway out of the rocker, there is a ring/seal external that should hold back oil inside the rocker arm, and compressing halfway will happen no.matter what if they aren't installed in a rocker arm, because of the hole on the side that let's oil out. After the piston/lifter thing compresses enough to cover the hole on the inside it stops dead. The compression holds them out.

I don't know if this link will work.. its a pic of a lifter fully disassembled. They aren't supposed to be taken apart though!

http://aspire.b1.jcink.com/uploads/aspire//IMAG0918.jpg

I'm thinking these are made to pump oil, and spin in the bore to avoid wear on the tip. Poor oil change habits and gunk leads to them sticking. There is nothing that can really fail aside from the external seal on the lifter case...maybe weak springs but if it moves it should pump...as long as it isn't fully collapsable, meaning the check valve ball or seal is dirty.

[nitrofarm]

Oh so there isnt a internal o ring? Its just on the outside correct?

[blkfordsedan]

I don't think they spin in the rocker arm bore. All I've ever seen were a pretty tight fit and Orings aren't really designed to be a dynamic seal. I can't see anything that would induce rotation either. Once the internal spring pushes the button out and takes out the lash, the pressurized oil should fill the cavity and make them solid(if the check ball is working).

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I think the riflings on the outside of the lifter casing and the oil pressure going through it might cause it to rotate. I have one that was still in the rocker, didn't take it apart at all, dunked the rocker arm and all inside a bowl of oil and squeezed it hard with a pair of channel locks, it really looks to me like there is some movement in the hla in the bore of the rocker arm, multiply that by how many times that cam spins and I bet it would do full circles.

[nitrofarm]

I don't think they rotate either,look at the wear pattern on them. Plus its not necessary like lifters that are riding on a cam. But that just my opinion & you know what they say about opinions.

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I think they do. And they're supposed to spin. They are made to pump oil, the only thing holding them open is the clearance between the piston and bore(internal in the hla)... And of course that stupid check valve, of all of these that I have cleaned, now only one won't hold a seal at the check valve...and that's the one I tried to drive a nail all the way through when I started this. The oil is forced out of the side and forces the hla to want to come out of the rocker arm, but the valve stem keeps it from doing that.

What I am seeing failing is just the check valve, and that's only from gunk. once I spray carb cleaner in that hole even stuck lifters pop out easy and stay out pretty firmly, until the oil escapes (from the side) and it looses pressure.