"Airstream," he said.

Like crawling up a desert grade in 1st gear (AT) at 20 mph in 100 degree
F weather.

On Wed, 2011-07-20 at 10:13 -0700, Jake de Villiers wrote:

> There's some almost information in your post Mike.
>
> The oil pump moves the oil at a fixed rate whether cold or hot. Just
> like your water pump, it increases the rate with RPMs.
>
> The sump, whether your finned aluminium VW one or my black painted
> steel Subaru one is hanging down in the airstream for a reason.  The
> cooling air pulls heat from the metal surface, allowing the heat from
> the oil to take its place.
>
> And yeah, the volume of coolant vs the volume of oil makes the temp
> gauge cycles very different from one another.
>
> Happy motoring!
>
>
>
>
>
> On Wed, Jul 20, 2011 at 9:10 AM, Rocket J Squirrel
> <camping.elliott@gmail.com> wrote:
>
>         On Wed, 2011-07-20 at 08:47 -0500, Dave Mcneely wrote:
>
>         >  Bottom line, I think the oil has a major heat source, and
>         only if an
>         >  external cooler has been added does it have a real
>         functional way to
>         >  dissipate heat other than to the coolant through metals
>         that both
>         >  contact and through such things as the sump.  The sump is
>         like a
>         >  reservoir of liquid, it cools slowly compared to a
>         radiator.   The
>         >  coolant has a large heat sink, and thus has a temperature
>         gradient.
>         >  That gradient includes the oil.
>
>
>
>         So what we're saying is that the oil is in contact with some
>         really hot
>         bits, and because there is high thermal resistance between the
>         oil and
>         the coolant, the oil can climb to much higher temperatures
>         than the
>         coolant.
>
>         It doesn't help matters that the hot oil drains down to the
>         sump which
>         isn't cooled by anything except the hot pavement under the
>         engine!
>
>         Others have also explained that while the water pump can move
>         a lot of
>         coolant up to the heat sink in the front, the little oil pump
>         just chugs
>         along pushing the oil more slowly and in lower volume so that
>         even if
>         there was an external oil cooler the size of the radiator, the
>         stuff
>         ain't moving fast enough or in enough volume to cool the
>         really hot bits
>         it's in contact with like the coolant can for the hot bits it
>         is in
>         contact with.
>
>         I think I've arrived at point where I have a better
>         understanding of why
>         the oil temp gauge shows higher peak temps during high engine
>         demand
>         than the coolant gauge shows -- which is the answer to my
>         original
>         question! Many thanks to all who have taken the time to
>         respond to my
>         inquiry!
>
>         -- RJS
>
>
>
>
> --
> Jake
>
> 1984 Vanagon GL 1.9 WBX - 'The Grey Van'
> 1986 Westy Weekender/2.5 SOHC Subie - 'Dixie'
>
> Crescent Beach, BC
>
> www.thebassspa.com
> www.crescentbeachguitar.com
> http://subyjake.googlepages.com/mydixiedarlin%27
>