Date:         Fri, 21 Jun 96 09:53:44 EDT
Sender:       Vanagon Mailing List <vanagon@vanagon.com>
From:         dcarment@ccs.carleton.ca (David Carment)
Subject:      oil cooler and misc

Hi all: I have been on digest mode as of late. There is a discussion to
which I might be able to provide some advice/insight re: oil cooling. I also
have a couple of questions.

First to the questions:

a) Can anyone on the list explain the protocol on buying used parts over the
internet? I have had good luck in the past buying a gas heater from Bill
Kennedy, an exhaust manifold from Mike Catlin, the listserv tshirt and vent
cap from Steve Johnson. My understanding is that it is normal for the
purchaser to  receive the used product prior to payment. Is this correct? 

b) Recently the Vanagon has been having an off and on hot start problem. It
is not starter related. To start the engine when either hot or warm it is
necessary to press the accelerator to the floor (this is FI). Would this
indicate a lean mixture? A faulty O2 sensor? In the past when this has
happened, Joel and others have suggested cleaning all grounds and contacts
shiny clean which seems to work. Any other ideas would be appreciated.

c) On oil cooling: Last weekend I pulled out the secondary oil cooler. The
cooler was situated above the tranny had a fan on top of it, connected to a
thermo switch and a remote located filter. I also installed two flexible
tubes (the kind for dryers) slung under the body but not low enough to get
in harms way. These vented directly to the cooler. In theory this was to
provide additional cooling. At one point I even installed scoops to create a
ram effect. Originally the cooler was bolted to the side of the van just
below the left rear intake and seemed to do well there but was also in harms
way. The cooler was a standard Empi tube type with fins. I used automatic
transmission cooler hose which is double walled and seemingly impervious to
heat and pressure. It had been installed since the spring of 1994 when we
drove back from California.

My experience with the second cooler was as follows:

a) operating temperatures ranged between 180 and 210 in the summer. Only
once did the oil temp reach 230 and this was last summer in 100 degree heat
at the top of a hill somewhere in Ohio. Winter temps were substantially
lower rarely exceeding 190 and sometimes staying as low as 150. This result
led me to believe that the thermostat may not have been functioning as well
as it could. To reduce the detrimental effects of possible premature wear I
have been using synthetic switching between Canadian Tire 15W50 and Syntec
5W50, noting little difference between the two and really having no idea if
they help except to note that all parts (rocker valves etc) are very clean.

b) The time that it took the oil temps to reach operating temperatures was
greatly extended. On a cool day it could take sometimes an hour before temps
reached 195.

c) oil pressure- since oil pressure was directly related to  oil temps it
makes sense that overall pressure would be higher on average. There is some
truth to this - but because of the extra length of hose and somewhat
convoluted path that oil must take startup pressures were about 10 psi lower
(ie 60psi in the summer as opposed to 70psi without). The use of synthetic
also seems to drop the pressure slightly (difficult to verify). A higher
weight oil also helps.

d)After startup and with the engine at normal operating temps, oil pressure
varied with rpm - 45psi at 180 for example and so on. However, once oil temp
reaches a certain point specifically 210 - an increase in rpm does not lead
to  higher pressure. My experience has been much like that of other members
- the pressure drops to between 30 and 35 psi once this and higher temps
have been reached. I should note this engine has 21 K on it and is
aircooled.  The oil light has never come on but once and this was last week
when I overzealously overfilled the oil (to compensate for leaking valve
covers-since remedied. I can confirm what others have said - overfilling
causes the engine to overheat very rapidly with oil temps climbing quickly).

e) Without the cooler - startup pressure around town is higher and overall
temps have not changed much in town. However we have yet to take the Vanagon
on a road trip. I have since bought a plate cooler  and proper filter mount-
the former will go in the engine compartment. A thermostat is a must in my
opinion for variable climates. The fan in my experience remains an option.
With a switch designed to go on at 185 (Bergmann's setup) you will find that
the fan runs continuously. I found that it had a negligible effect on
overall temperatures. I installed a light in the dash to monitor its operation.

f) So here is what I conclude from all this: keep the engine clean, well
tuned, run synthetic (if you think it helps) and if you plan extensive road
trips think about a second  cooler but only if you can route the tubing in
the shortest possible fashion in combination with maximum cooling effect AND
call on the second cooler only when it is necessary.

We need some hard data to actually compare across cases with and without.

Points to consider: 

- what is the effect of cooler than average oil in combination with heads at
normal or higher temps?

- what effect does adding extra oil have on cooling capacity (in the sense
that there is more volume with a second cooler)?

- what might the alternatives be? - better pump? dry sump? bigger sump?
synthetic?

- would installing the cooler in the engine compartment really have an
impact on engine heat?

Cheers - DC