Date: Wed, 30 Apr 2008 14:55:25 -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: <BAY125-F36926EBAAFD41EA8CB23C9A0D80@phx.gbl>
Content-Type: text/plain; charset=iso-8859-1
I have a VDO oil pressure gauge installed and the pressure usually jumps up to 50 psi at cold idle and drops down to about 17 psi at warm idle. So I don't think too much oil pressure is the problem.
Although something goofy could be going on with the heads, I don't think so. This is a low milleage Boston Bob rebuild and I doubt he would have gotten this wrong. In addition, the van ran pretty well for the first year or so that the motor was installed.
I also think it is unlikely that I overheated the heads. I have had a VDO oil temp gauge installed since the first time the motor was started and my oil temp has never climbed above 210. I don't have a cylinder head temp gauge, so it is possible that the heads overheated while the oil stayed cool. However, this seems unlikely since all the cooling tin is clean and in place.
I don't know what the problem is, but it has been around for several years and I can't figure it out. I am very frustrated. I wish Benny would open up a shop in Cincinnati so I could have him look it over. My Buses by the Beach buddies are also stumped on this one.
Dennis Haynes <d23haynes57@HOTMAIL.COM> wrote:
Maybe you need to check your oil pressure on the engine when cold. A jammed
relief valve can cause the presure to go high enough to force the lifters
open. The pressure should never go much above 60 psi. Weak vlave springs or
missing inner springs can also be a problem. If the heads were rebuilt and
the seats were cut, the springs need to be shimmed to compensate for what
was cut off the seats or the valve faces if they were machined. Spring
tension is critical. Being an air cooled engine it is also possiblle that an
over heat condition also ruined the springs.
Dennis
>From: Jake Beaulieu
>Reply-To: Jake Beaulieu
>To: vanagon@GERRY.VANAGON.COM
>Subject: Re: Lifter adjustment VOODOO
>Date: Wed, 30 Apr 2008 13:06:01 -0700
>
>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 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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