Date: Wed, 30 Apr 2008 13:06:01 -0700
Reply-To: Jake Beaulieu <jake_beaulieu@YAHOO.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Jake Beaulieu <jake_beaulieu@YAHOO.COM>
Subject: Re: Lifter adjustment VOODOO
In-Reply-To: <4818B258.9000704@cox.net>
Content-Type: text/plain; charset=iso-8859-1
Yeah, this topic is giving me a headache. I have an 82 AC Westy. If I set the lifters to 0 clearance it runs "OK", but put it one or two turns in and it barely runs. A couple weeks ago I measured the compression at 0 clearance, then set the lifters to +1 turn and let it sit for TWO weeks. When the van first started after sitting for two weeks it ran great until the oil pressure came up (5-10 seconds), then it just barely chugged along. A compression test revealed that the compression had dropped from about 170 psi to 120 psi on all cylinders (I don't have the numbers in front of me). Backed the lifters out to 0 clearance again and compression jumped back up to 170 and it ran "ok".
Since the van ran great at +1 turn until the oil pressure came up, I am wondering if the valve springs are weak. It is as if the oil pressure is high enough to fill the lifters, then continue to pump up the lifters to the point that they are compressing the valve springs and forcing the valves open. I don't know how one would go about measuring the strength of the valve springs?
jake
Mark Drillock <mdrillock@COX.NET> wrote:
The problem is that lots of times the engine won't run right if at all
when first set to either 1-1/2 or 2 turns. It can take time for full
lifters to bleed down a little. Turning in the screw on a lifter that is
fully expanded and filled with oil just opens the valve and then
compression can be low or even zero. Wait some hours or days and the
constant pressure from the valve spring will force some oil to escape
from the lifter and eventually things will be ok. This problem is why
over the years this topic has been so controversial here. A fully bled
lifter is too long at first because it has too much oil in it. Put that
lifter under tension from the adjuster screw and the oil won't compress
but the valve spring will and the valve will open. Left that way for a
while the constant pressure from the valve spring will eventually
squeeze some oil out, which is what is needed. Then when the engine is
started the lifters will pump back up but only to the right length.
Mark
David Kao wrote:
> Officially it is supposed to be 2 turns. I have tried 1-1/2 and 2.
> All worked fine. The lifter self-adjusts. there is really no difference
> between 1-1/2 and 2.
>
> David
>
>
> --- Jake de Villiers wrote:
>
>> One of those guys has made his living rebuilding VW engines for a long time
>> now.
>>
>> I'd go with his recommendation.
>>
>> On Wed, Apr 30, 2008 at 7:54 AM, Mike S wrote:
>>
>>> At 10:27 AM 4/30/2008, Chris S wrote...
>>>
>>> Although I'm getting ZERO messages from Gerry again, I'm hoping
>>>> knowledgeable folks will reply to me directly.
>>>>
>>>> I'm confused about proper lifter adjustment. According to Bob Boston
>>>> I
>>>> should do 1.5 turns past contact. According to Ken Wilfy I should
>>>> just
>>>> leave the lifters set at first contact.
>>>>
>>>> Sooo... what is it? And why?
>>>>
>>> 1 1/2 turns in from a fully expanded lifter. Because it allows the
>>> lifter to adjust itself in either direction. If you set it at "first
>>> contact," the lifter can't expand to adjust for a valvetrain which is
>>> getting looser.
>>>
>>
>>
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