Re: [T3] Engine Oil & Cooling

["Toby Erkson" <air_cooled_nut@pobox.com>]

À? Kind of confusing...

In order for oil to cool the engine the heat it absorbs needs to be released.
It is part of the cooling system i.e. it directly cools the engine.  I would
venture to say if an oil cooler was simply to keep the oil from breaking down
then those of us with bigger engines (producing more heat) wouldn't be running
with extra oil coolers ;-)

Heat isn't the only thing that 'damages' oil.  When the oil gets squeezed,
like in the bearings and gears, it goes through sheer damage and that breaks
down oil as well.  An oil cooler wouldn't do squat to help save it in that
instance (and that instance happens a LOT in an engine).

I'm not sure I agree with the 1/3 theory -- maybe somebody with a more solid
knowledge of physics <cough>Jim<cough> could help out here.  During the power
cycle, if 1/3 of the power is lost in the cylinder walls and the other 1/3 is
for the actual power of the cycle, how can another 1/3 escape to the exhaust?
If it's through the valves then the intake as well as the exhaust would become
heated -- not good...but that doesn't happen anyway.  Now, during the exhaust
cycle then yes, heat goes that direction but then it's no longer in the power
phase.

     Toby Erkson  --  air_cooled_nut@pobox.com
     '72 VW Squareback, '95 VW Jetta, '81 Gold Wing
     http://www.icbm.org/
     Portland, Oregon

----- Original Message -----
> >From another list is this gem that might help
> in any discussions about engine cooling. Note
> that there is nothing mentioned about oil. I
> think that the cooling of the oil is to prevent
> it's breakdown and provide lubrication, and not
> to directly cool the engine, but I could be wrong.
> I'm many digests behind. What is the heat path
> to the oil?
>
> "In small engine repair it states 1/3 heat is
> conducted through cylinder walls, 1/3 for power
> in the cylinder, 1/3 escapes in exhaust."
>
> Jeff - cross posting to T2 & T3 lists

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