clemsondave

Finishing up my DD rebuild of a 6.0L and the valvetrain is killing me. I have a ticking noise, but the bigger issue is the lifters are bleeding down within 10 seconds. We have measured for the correct pushrods - no change. We put various length rods in it to get preload from .030 to .080 - no change.

6.0L iron block
317 heads
mild Comp Cams cam (210/216 114/112 intake-.555; exh-.561)
new LS7 lifters
new LS6 springs

oil pressure is fine at 60#. Oil is making its way through the pushrods.

Tried the following rods. 7.400, 7.350, 7.330. Zero lash with a comp cams length checker is 7.275.

Anyone seen this before? ideas?

elias_799

iTrader: (8)

what oil do you use ? try thicker oil, it will prevent lifters bleeding out to quickly. good luck

clemsondave

thanks for the thought. We used 20/50 to break it in, plus it had some assembly lube in it. It was pretty thick. Now has 5/30 in it. No difference.

Description of what we are seeing:
manually crank motor until the springs are compressed.
within 10 seconds or so, the springs open up - pushing the lifters down. Or, the lifters are falling down allowing the springs to open.

what we are trying to figure out:
are the lifters giving out? or,
are the springs too heavy and pushing the lifters down?

Our best guess right now is that the new lifters are bad.

Would bad plastic lifter trays have anything to do with it?

Anyone else using yellow LS6 springs with LS7 lifters? I assume that combination is ok.....

elias_799

iTrader: (8)

ls7 lifters would work without a problem.

clemsondave

Can anyone think of another explanation other than bad lifters? Are their any tests to prove that the lifters are faulty?

500hpZ06

iTrader: (11)

So you have had the engine running? If so, for how long?

clemsondave

Yes, 300-400 miles. It runs great. Just the sewing machine tapping noise. The only time it went away was when we did 2 WOT passes for tuning. The ticking completely went away until the motor cooled.

DaddySS

Not a lifter expert but the oil filter has an anti bleed down valve in it to keep the oil in passages. Could a bad filter be letting the pressure bleed down?

clemsondave

thanks for the thought. Changed the filter when I did the oil change (Bosch then K&N). No difference.

DaddySS

In which - the tapping or the bleeding down? How many turns did get on the rocker bolts when you tightened them down?

clemsondave

Changing the oil and oil filters did not change the ticking noise (while running) or the lifters collapsing as we watched them with the motor off.

We tried 3 different pushrods from .030-.080 preload. No change with any of them as far as the lifters collapsing. We did not swap all of them out to see if the ticking would go away. Trying to solve the lifter issue first.

500hpZ06

iTrader: (11)

I don't know... maybe an internal passage/leakage problem? The front oil passage plug (underneath the timing cover), rear plastic 'barbell' plug (installed backwards?), or maybe an issue with the front or rear cam/galley plates?

clemsondave

Interesting thoughts. I replaced those with new parts. I'll ask the guy helping me to see if he specifically remembers anything special about those.

Question: if one of them falls, would that cause the pressure to go away and the others would fall? Maybe just one is bad.

500hpZ06

iTrader: (11)

Yeah, not sure if it is a longshot, since you seem to have good oil pressure. I just wonder... if the front plug was missing/pushed out... but the timing cover/gasket would hold enough pressure, yet be constantly bleeding off oil, you might still get 'full' lifters at higher RPM/pump speeds... ?
...same possible scenario if that rear 'barbell' plug was backwards???