Date:         Mon, 17 Apr 1995 17:00:47 -0500 (CDT)
Sender:       Vanagon Mailing List <vanagon@vanagon.com>
From:         Gerald Skerbitz <gsker@lenti>
Subject:      Re: HELP: '67 Deluxe Saga - Vaporlocking? (fwd)

=========================================================================
Date:         
Sender:       Vanagon Mailing List <vanagon@vanagon.com>
From:         
Subject:      Re: HELP: '67 Deluxe Saga - Vaporlocking?

>The oil pressure is 20 psi @ 2000 RPM.   He says this is about 1/2 
>what it should be.  I have no knowledge of oil pressure/RPM.
>
>Would this be low enough that the oil would not be circulating 
>through the oil cooler properly?
>
>The mechanic guy suggests that we replace the oil pump, sighting that 
>the pump might not be working fully.  Does an oil pump work 
>half/way or is it a work/no work part?  
>
>| - Mike White                    |  
>| <mike.white@.law.utah.edu>      |  
>| <mwhite@eng.utah.edu>           |
> 

OK, I'll bite,

Low oil pressure is the classic VW 1600 air-cooled case/bearing problem.
The crank bangs out the saddle of the #2 center main bearing, and others too
if it's bad.  This causes oil to pass between the bearing and the case
rather than get to the journals.  Most engines last a quite a while even
with this leakage, it's the rod journals that will likely overheat from oil
starvation.  There could be nothing at all wrong with the oil pump.
However, putting a new, larger (30mm) pump in should bring the pressure up,
but may cause blow-outs when cold.  An oil pump cannot work "halfway", it
could, if installed badly or extremely old, have poor tolerances that could
cause it to be weak.  It is simply two gears running together, one driven by
the camshaft, the other running free in bushings.  

Does your oil light stay on a long time when first starting?  If so, maybe
the engine would last longer with better pressure.  Does the engine run hot?
Either the carb/timing/compression is off and/or the case is sad and can't
hold it's bearings tight.  If you do rebuild, don't use that case, get a new
AS21 case.  

In any case, I don't think it has anything whatsoever to do with your
vaporlock problem and would investigate other problems.  20 psi @ 2000 is
low but shouldn't cause vaporlock.  Haynes says 42 psi @ 2500 rpm, 28 as a
minimum.  Try going to a straight 40W and see if it helps.

I think the fuel pump has a cracked diaphragm and holds pressure
intermittently...?

Eugene
'71