'springy' valve rocker

TrollFromDownBelow · Post by **TrollFromDownBelow** » Sun Nov 16, 2008 9:36 am

Yesterday i replaced the o rings on the pushrod tubes on the 1/2 bank. When I finished, started to adjust the valves, and noticed that the exhaust rocker on number 2 felt 'springy' when i pulled back on it. It was like the mecahnism had some 'give' to it. Thinking I may have assembled the valve train incorrectly (pushrod not fully seated, etc), I pulled it apart, pulled the pushrod's out, and reassembled everything...still felt springy. Not knowing what else to do, and needing to move the bus, I adjusted the valve by pulling on the rocker to remove any slack caused by the "spring" (about .006 worth of slop due to give) and then adjusting to .006. Fired it up, seemed to run fine....no funky valve train noises (btw .... 1st tried setting clearance without removing slack, and the valves sounded noisy/loose), what would cause this? There was quite a bit of sludge/saw dust (long story) in this bank .... cleaned all the components thoroughly before reassembling...was wondering maybe the rocker might be worn...cleaned out some sludge that was taking up the slack?

Post by **Amskeptic** » Sun Nov 16, 2008 7:29 pm

TrollFromDownBelow wrote: number 2 felt 'springy' when i pulled back on it.

That thar is a hydraulic lifter. We knew this, no?
Colin

TrollFromDownBelow · Post by **TrollFromDownBelow** » Sun Nov 16, 2008 7:52 pm

So I have 7 solid lifters, and one hydraulic? I don't recall this from our visit...anything else that could cause this...ie I reinstalled something incorrectly?

Post by **Amskeptic** » Mon Nov 17, 2008 3:14 pm

TrollFromDownBelow wrote:So I have 7 solid lifters, and one hydraulic? I don't recall this from our visit...anything else that could cause this...ie I reinstalled something incorrectly?

Color me mystified.

When you pushed/pulled the rocker in question, did it pull from the valve side and push down the pushrod? That's a hydraulic. As for the others, are they just beautifully pumped up? Seems I remember us adjusting them to .006". If it is a hydraulic engine, I am retiring TODAY if we set them all at .006" Usually you have two tip-offs to a hydraulic engine. One is no spring between rocker arms on each set, just a solid spacer. The other is steel pushrods instead of the aluminum (fatter cross section).

Man. . . what do you have in there?
ColinBatedBreath

TrollFromDownBelow · Post by **TrollFromDownBelow** » Mon Nov 17, 2008 9:59 pm

I'm starting think...not sure if it is the power of suggestion, but vaguely remember you saying something about one of the lifters being hydraulic. Nothing in your notes (I actually have them from all three visits...which is good...beginning of my to do list

To answer your question, yes, when I push down on the pushrod, it gives. It did have a spring between (if you meant the wire spring) between the sets of rockers. I can assure you, that none of the other rockers have any give...at all. Pushrods 'felt' like they were made out of aluminum...all were the same girth.

Me thinks this may have been a remnant hippy fix....not sure if you recall, but the engine has a helicoil in it ... in the same cylinder as the one hydraulic valve. Coinkydink? I think not.

Things that make you go hmmm.

whaddya think? engine seems relatively happy .... accelaration test (at least the 50-60) doesn't seem to be too far off the BobD....other than it's oil consumption...just drive it?

Post by **Amskeptic** » Mon Nov 17, 2008 11:57 pm

TrollFromDownBelow wrote: whaddya think? engine seems relatively happy .... accelaration test (at least the 50-60) doesn't seem to be too far off the BobD....other than it's oil consumption...just drive it?

Just drive it, but we need to come up with a solution for that lifter. It should not be run with clearance if it is hydraulic, the circlip will get beaten to death. Dang, this is a new one in the lore. . . . a three legged cheetah with an artificial hip or sumpin'

vdubyah73 · Post by **vdubyah73** » Tue Nov 18, 2008 5:41 am

You can look down the pushrod tube with out removing the rockers and see the wire clip on hydros. It takes a bright lite and some contortions but it can be seen. Or just remove that set of rockers and pushrods and verify with certainty.

TrollFromDownBelow · Post by **TrollFromDownBelow** » Wed Apr 08, 2009 3:23 pm

Just as a follow-up... Did the rear brakes last weekend, and noticed my valve cover gaskets were leaking. Started to second guess myself; checked the lifter again and felt hardly any give, so set the clearance back to .006. Now she sounds noisy again... gonna have to pull off the rocker assembly and check for sure.

If I do have a hydraulic lifter, can it be replaced without removing the head?

vwlover77 · Post by **vwlover77** » Wed Apr 08, 2009 3:53 pm

Yes. Just the pushrod tube needs to be removed. I use a piece of picture hanger wire with a very small 90 degree bend at the end as a hook to reach in and grab it by the center hole or at the edge of the lifter body to pull it out - slowly. Be ready to catch it when it comes out!

Post by **Amskeptic** » Wed Apr 08, 2009 7:12 pm

TrollFromDownBelow wrote:Just as a follow-up... Did the rear brakes last weekend, and noticed my valve cover gaskets were leaking. Started to second guess myself; checked the lifter again and felt hardly any give, so set the clearance back to .006. Now she sounds noisy again... gonna have to pull off the rocker assembly and check for sure.

If I do have a hydraulic lifter, can it be replaced without removing the head?

As per Don, and as per me please adjust that lifter to 1 1/2 turns IN from loss of clearance. If you were to accidentally do the 1 1/2 turns in on a solid lifter, you would know it pretty quickly as the engine would run poorly. If you are certain that this is the mystery hydraulic, do the 1 1/2 turns from no clearance where clearance is established by a light (read: gentle) clicky clearance. Do not be muscling the rocker arm back and forth, just enough to get a little light clicky like a solid lifter, and turn the screw with your fingers only if you can, until the light clicky goes away . . . add 1 1/2 turns in, yer done. The engine should run flawlessly and quietly once more. If you want to slap a solid lifter in there, please check the bottom of the lifter you pulled first. Is it smooth? Is it flat to almost convex across the contact face? If it is pitted or obviously concave, please put it back in and deal with one hydraulic lifter + 7 solids. A badly worn lifter has likely "married" the camshaft lobe. If you stick a new lifter on a worn cam lobe, you might find that you destroy the lobe due to insufficient contact area with a new properly convex lifter.
Colin

TrollFromDownBelow · Post by **TrollFromDownBelow** » Thu Apr 16, 2009 7:40 pm

Okay. Did as recommended...turned in screw until zero clearance, no click with just a slight pull back. turned in screw 1.5 turns, fired it up, and ran like ... well ran like it has a solid lifter set 1.5 turns in. Turned it off (only ran for abt 30 seconds) readjusted .006 out and cranked the two 11 mm nuts down a half turn on the rocker assembly thinking that this may have caused the 'slack' I was feeling. Fired it up, sounded good. Drove it 50 miles to my GF's house, and she ran like a top.

Gonna change my sig.

TrollFromDownBelow · Post by **TrollFromDownBelow** » Mon May 11, 2009 5:36 am

changed my mind ... I DO have a hydraulic lifter.... readjusted (again, for the umpteenth time) and all is well.

vwlover77 · Post by **vwlover77** » Mon May 11, 2009 9:15 am

Yep. The hydraulic lifter takes time to respond to its adjustment. If it's all pumped up and you crank it in 1.5 turns and immediately start the engine, it will not let the valve close until it bleeds off some of its internal pressure.

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'springy' valve rocker

'springy' valve rocker

Re: 'springy' valve rocker