Ahhh... One of the previous suggestions was to get the oil "clips" and adjust
the engine while it is running. This might be the easiest way to proceed.
The "clips" go on each rocker to keep the oil from splashing in your face
while the engine is running.
To do the procedure, you remove one valve cover (if I remember it's a V6
- or was it a V8...) Next step is to attach the clips to each rocker such
that it blocks the oil from spraying all over the place (and in you face).
Then with the engine running, you simply go to each rocker, one at a time,
and back off the adjuster until it starts "ticking". That's the point that
positive lash (a gap, "slop" ) in the valve train. Slowly tighten the
valve until the ticking stops - that's the zero lash point. Then turn the
adjuster the 1.5 turns. This puts the lifter somewhere in the middle of
it's range, so the 1.5 turn doesn't have to be exactly perfect, just
close. You repeat this process for each valve on the one side.
Then install the valve cover. Then start over and do it again on the other
side.
It's been years since I've had to do this to an engine (a small block Ford
the last time), but it works very well. It can be messy depending on the
engine and how much of a "lip" the bottom edge of the head has (where the
valve cover seats). Sometimes, some of the oil will "spill" over the sides
of the head and down the engine. Lots of rags help. People that have to
do this often have even been known to get an extra valve cover and drill
the proper size holes in the top so that the socket can be inserted to
adjuster the rockers. It tends to keep the oil in the engine better that
way...
By the way, the above procedure was actually the factory recommended
method for many cars....
It really does sound like a better way than starting the engine between
each valve adjustment. Besides, the valve lifters will expand with oil
pressure. Once you shut off the engine, there is no more pressure, and
backing off the adjuster will not allow the lifter to expand any more than
it will just simply be backing off all the lifters at once.
-----Original Message-----
From: Bruce Wolfe (wolfe) [mailto:wolfe@cisco.com]
Sent: Tuesday, January 14, 2003 3:10 PM
To: Mullen, Tim; shop-talk@autox.team.net
Subject: RE: Slightly OT - Adjusting Hydraulic Valves
Tim, I think you are mostly right, but I didn't THINK (realize) I was
pushing them down.
For anyone who cares, I think my problem may have been that I had a
pre-load on all the valves and it took me to long to finally adjust
them. By the time I did, and with various rotations of the crank, all
the oil had been forced from the lifter and they had all collapsed. What
follows is the logic that lead me to that conclusion. Along with my
current plan to proceed.
**********************************************************
Bruce,
Disregard my previous advice. See below. I misunderstood what was
happening.
There IS a spring in the lifter but it is pretty weak, not nearly enough
to push a valve open. The lifter relies upon trapped oil in it to
maintain it's proper length. I don't know exactly what the 1.5 turns
that you originally mentioned is for. Sounds like the lash is set too
tight & the lifters are bottomed out & holding the valves open.
The pre-filling that I mentioned would only work if the valve
adjustments & parts had not been changed.
A better way would be to set each cylinder to TDC, adjust the valves to
just start to push the valve open, this will collapse the lifter,
squeeze any oil out, & then back off the adjustment (several turns,
maybe one & one half) until a .040" feeler gage will fit in the valve
stem gap. The object is to make sure that the lifter is fully collapsed
& then to set the valve clearance to .040". The .040" gap will close up
when the lifters are pressurized & pumped up. DON'T try to fill the
lifters before doing this.
Let me know if this is clear & how it goes.
Dave
**********************************************************
Dave,
I think you're dead on here. Question: How much travel would a typical
lifter have from being fully compressed to fully expanded? Based on your
input, I would assume ~0.080". I think the 1.5 turns _assumes_ that the
lifter is fully expanded and that you are centering the lifter in the
middle of it's adjustment range. If that is true, then adjusting the
valve till it _bottoms_, then backing off 1.5 turns should also
(approximately) center the lifter in the middle of it's range.
Last night, I did back off the valve compression, threw the fuel
injection and all the associated sensors back on and it fired right up!
So here's my latest plan (since I still need to get the darn things
ADJUSTED): Fire up the engine, let it run for a minute or two to fill
the lifters. Shut it off and quickly turn it to #1 TDC and adjust all
the intake and exhaust valves I can. I'll be careful to just take up the
slack (and not compress the valve till all the oil is out of it). Then
add my 1.5 turns. Fire it up again, let the lifters refill, then turn it
to #4 TDC and adjust all the remaining intake and exhaust valves. The
manual makes it clear which intake and exhaust to adjust, i.e. those
that are not being compressed.
I think my problem may have been that I had a pre-load on all the valves
and it took me to long to finally adjust them. By the time I did, all
the oil had been forced from the lifter and they had all collapsed.
**********************************************************
Bruce,
Right on -- all of the way, all items. Good plan.
I am guessing, but I would expect the lifters to have .080" to .100" of
range. It isn't terribly critical to have them centered as long as they
don't run out of travel in either direction. Running out of travel in
the compressed direction would hold a valve open, & would be obvious.
Running out of travel in the extended direction would cause a noisy
valve. Also fairly obvious.
I guess that you could use feeler gages to find out how far 1.5 turns
moves things & assume that 1.5 turns is one half of the travel.
Depending upon oil viscosity & lifter clearances, it could take anywhere
from 8 seconds to 4 minutes for a lifter to bleed down. Most likely on
the minutes end of the scale.
Regards,
Dave
> Bruce Wolfe (wolfe) [mailto:wolfe@cisco.com] wrote"
> >
> > It said to adjust the valves to zero lash (compression stroke) then
> > ADD 1.5 turns to preload the lifter. <...>
> >
> > The car is acting more like it has solid lifters than hydraulic
> > (possible, it is pre-owned, but not likely). Could the springs on
> > every lifter be broken an the lifters all collapsed?? I'd
> prefer NOT
> > to take the intake manifold off, but if I have to to check the
> > lifters, I will.
>
> Assuming that by setting it to zero lash you kept "rocking"
> the rockers,
> as you adjusted them closed, with a light touch and stopped when any
> clearance disappeared. This would allow the spring in the lifters to
> "uncollapse" the lifter. Then the additional 1.5 turns would
> compress
> the lifter to part way between the collapsed and the fully
> "open" positions.
>
> If you were pushing the lifters "down" while adjusting to
> zero lash, then you were manually collapsing the lifters.
> The additional 1.5 turns would
> then keep the valves from closing. If this is not the case,
> then you either have solid lifters, or they are all
> collapsed. In either case, you may need
> to get a look at the lifters...
>
> Tim Mullen
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