Re: [T2] Re: Oil cooler lines

[Robert Taylor <rtaylor@xxxxxxxxxxxxx>]

> Did you use a stock oil cooler or go to the tube type?

Neither. It's a plate type cooler. Made by EMPI? I'm a little fuzzy on
details at the moment, 7 years after install (and the bus is parked a long
way away). As I recall there were two possible standard hose sizes and I
used the larger of the two. I think it was 3/8" vs. 1/2" internal
diameter? As I recall there were two sizes of plate coolers and I went
with the smaller of the two (14 slots vs. 17 or 19?). I attached an
adaptor to the place where the stock oil filer goes, with two darted hose
bibs, one out and one in.  Outbound hose goes forward, through an oil
filter on a separate mount, then through the auxiliary oil cooler, then
back to the in point. If I were to really do it right, I would install a
thermostat oil bipass valve near the engine. These ran about $50 back in
'94 and were supposed to always run at least 10% of oil through the cooler
system, but shunt the remaining 90% directly back to the engine when temp
was cool and run the full 100% out to the cooler when temp was hot. I live
in a very temperate climate (then San Diego, now Santa Barbara, CA), so
the thermostat seemed like an optional piece of hardware for my tight
budget. And my main objective was to make my bus hardy enough for heavily
laden runs into deepest, sunniest Baja CA, where too cold is never an
issue.

I've always had a bit of a problem with minor oil dripping from the bib
connectors at the engine. I've used a combination of Permatex gasket
compound and hose clamps on those bibs. Some have warned me against using
much (or any) Permatex, because if any bit of it got loose inside the oil
system it could easily plug up some small oil galley and starve a bearing
for oil, with direct and expensive adverse results. Easy to imagine. I
used the low end, black rubber oil hosing. It might leak less if I went
for the higher grade red or other oil hose. Or had different hose bibs. Or
something.

Bob Hoover (as in, Sermons of...) has described doing an auxilliary oil
cooler with stainless steel woven hose and airplane hardware type
connectors. No leaks. Beautiful. Immaculate. Costs a lot more than what I
did.

The general word I hear on the type2 list is that plate type coolers cool
better than tube type ones. OTOH, I think they're mostly talking about the
low end ones and not the Volvo part you are describing.  You might be able
to model which is better, if you're an engineer with nothing better to do.
It's all about airflow and surface area for cooling. And I've never seen
any real data about which works better, though those with opinions hold
them pretty strongly, probably based on a fair amount of experience.

The bottom line I gleaned from looong type2 discussions about synethetic
vs. non-synth engine oil seems to be that synth oil can take higher
temperatures, but has lower heat conductance, so it functions less
efficiently as an engine coolant. I've never seen a definitive line of
evidence and reasoning leading to choice of one type (or grade of oil) for
the bus. For temperate climates, 40 wt vs. 5-40 (10-40?) vs. 20-50 still
seems like a point up for grabs.

And you can always expect to hear from the "stock only" guys who will tell
you that the stock system is enough cooling by definition, if your engine
is built just right. If think you need extra non-stock cooling, then you
are obviously doing something else wrong, by definition.  And you are
addressing the symptom, not the cause, if you go for non-stock cooling
instead of identifying and correcting whatever other problems you may
have. See Dr. Tim's recent post for an example of this viewpoint. I'd like
to believe this. I'd love to see what one of those guys would say of my
engine if he could actually inspect it and tell me what appears to be
missing from my apparently perfectly intact, properly built, properly
adjusted stock engine (exc. for the oil cooler). Maybe they'd call
bullshit on my my VDO oil temp gauge or sensor? Not to diss those guys-
they're probably very good mechanics with a lot of experience behind their
opinions. But my experience with my one engine does not match their
opinions with their many engines.

I spent a lot of time tracking down all the seals, adjusting timing just
right, even playing with different octanes of gas, and ultimately I
decided to install auxilliary cooling on my '78 Westy for the same reason
you want to: I had an apparently complete, properly functioning engine
with all the seals, well adjusted, recently rebuilt, what else could I be
missing, and my operating oil temp nevertheless hovered at 250F and a
little above. I thought it was supposed to stay below 210F (So say John
Muir and others, in discussions of oil and when it starts to break down),
but straight talk on this simple point (how hot is OK?) is pretty hard to
come by.

With my aux oil cooler, my bus has gone lots of places aircooled buses
aren't supposed to go. Like across Arizona at high noon in July, with temp
staying below 250F. I think maybe the all-stock guys would counsel not
driving at all under those conditions.

Good luck,
Surfer Bob
1978 Westfalia, the surf/luvbus