Date: Thu, 28 Jun 2007 08:54:47 -0600
Reply-To: vanagonvw <vanagonvw@GMAIL.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: vanagonvw <vanagonvw@GMAIL.COM>
Subject: Re: Hydraulic Lifter Adjustments
In-Reply-To: <2cb866ef0706280655o7e57e41cpab04bb69d5f27829@mail.gmail.com>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
>
> Date: Wed, 27 Jun 2007 21:49:34 -0600
>> From: vanagonvw <vanagonvw@GMAIL.COM>
>> Subject: Hydraulic Lifter Adjustments
>>
>> 81, air cooled. Hydraulic lifters
>>
>> Damn, it is really hot here in Northern Utah... Sweating like a madman
>> in the garage, and under the van.
>>
>> I am thinking this topic gets bandied about almost as much as tires :-)
>> I have read the archives, and other forums. Still want to better
>> understand some things tho....
>>
>> To get started, I took the easy way, and went with number one. Used the
>> timing marks, and only needed a few tries to get the piston to stay up,
>> and do the test. It failed, with 90psi in, and about 50psi reading, or
>> 45% leakage. In order to see what was going on with the valves, I took
>> off the cover, and noted that with the piston certainly at TDC, the
>> intake valve had a small amount of 'play' or 'lash' between the rocker
>> arm, and the stem.... The exhaust valve, however was leaking a lot,
>> based on what was coming out the tailpipe, relative to the intake, and
>> it had no play or lash at the stem. So, I backed the adjuster screw out,
>> eventually two full turns, resulting in a small amount of play, and
>> apparently this allowed the valve to close completely, and the leakage
>> went down to just 20%, which is not all that bad for an engine with 200K
>> miles on it. I would take that if they were all at 20%.
>>
>> What did I learn, and how come I am supposed to set zero lash, at TDC,
>> and then one to two turns down, depending on which article I read? I
>> don't understand the notion of adjusting that rocker arm, so that it
>> actually opens the valve at a point when it is supposed to be
>> closed..... When the lifter pumps up, won't that make it even worse? Is
>> that indicative of a bad lifter? Weak springs? Wrong interpretation of
>> the procedure <g>
>>
>> I would really like to understand how to set it up properly.
>>
>> (section two)
>>
>> It may be a totally moot point however, as number two, after an hour of
>> trying to find TDC that would not push the piston down, I found almost a
>> 50% leakage, mostly exhaust if I am any judge, and both valves had a
>> small amout of clearance. They were not open at all, based on the
>> ability to pull the rocker arm back off the stem, on both of them. Not a
>> lot, but enough to know, I have a problem....
>>
>> My only choice is to get the remaining cyls tested, adjust the valves as
>> best as I can, and park the van, indefinitely, but I need it as a spare
>> set of wheels. My Ford Taurus trans went out today, so without the Van,
>> I have nothing to drive, and I at least need something in case of an
>> emergency for my kids, or hell, even me :-) No intention of driving it,
>> unless I absolutely have to, as that could make things ugly if its a
>> seat that has dropped a bit, but I cannot afford a new trans for the
>> Ford, let alone a new set of heads for the van, so I want to set the
>> valves up as best as I can. Plus, good practice, in case I ever get to
>> be able to fix this.
>>
>> Anyway, I hope things maybe look somewhere in the future, but for now,
>> I want to do the best I can with what I have, so any education from the
>> resident experts, would be appreciated. Kind of two issues here, but I
>> want to learn what it is, that I am seeing on both cylinders...
>>
>
> I'll try to keep it brief because you will likely hear exactly what
> you need
> to know from some of the list experts.
I am happy to hear from anyone who has been here. I am very confused as
to how to proceed :-)
>
> Currently I am
> running 0 turns on my a.c. vanagon as it yielded the highest compression
> (big difference from even 1/2 turn in on a few valves).
I tend to agree with your assessment. The thing that I am not able to
understand at the moment, is, I have the cylinder at TDC. If I set zero
lash, all is well and the leakage is acceptable If I go a full turn, it
opens the valve, and the leakage gets worse, obviously. How do I explain
to myself, that it is correct to tighten the rocker arm, so that the
valve never closes?
The engine is certainly cold. I am not adverse to finishing the testing,
and then running it up to temp, and adjusting them again, but I am
stumped right now, as to why I would want to adjust a rocker arm, so
that the valve never closes all the way....
> I hope that helps
It sure helps a lot, and I appreciate it. Being so dang hot, I tend to
work a bit, and then take long breaks, which maybe gives me too much
time to think about what is going on :-)
I appreciate the point on pulling the head, with the engine in the
van... I am not sure if I will pull it, or park the van. It makes me sad
to think I won't be able to use it anymore, but sometimes, reality has
to be faced.... :-(
Gonna study on how to drop the engine..... I tend to overthink these
things...
Very much obliged.
John
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