Re: oil cooler

[yaron sadot <sodot@domain.elided>]

still water is colder then oil

i come from tuning zone so i know some on this

yaron

Greg Hermann wrote:

> At 8:56 PM 1/4/00, yaron sadot wrote:
> >water cools the oil
> >
> >thats why the hose is there
>
> It also can warm it, as when the coolant warms up much faster than =
the oil
> from a cold start.
>
> Actually--the ideal coolant temp is about 195=B0 F, at its maximum =
(going to
> the radiator), ideal oil temp is about 180=B0 F. at its minimum (go=
ing to the
> galleries). With normal flow rates for each, the minimum temperatur=
e
> (leaving the radiator) for the coolant is about 20=B0 F lower than =
its
> maximum (at maximum engine power output), and the maximum oil tempe=
rature
> is 210=B0 or 220=B0 F., leaving the bearings, also at maximum engin=
e power
> output level.
>
> Heavy trucks even use a "shutter" on the air intake to the radiator=
. The
> shutter closes at light engine loads or in cold weather so as to no=
t let
> coolant exit the radiator at anything less than about 175=B0 F. Thi=
s avoids
> any tendency to "shock" (thermally distort or stress) the engine bl=
ock or
> heads with too cold coolant coming back from the radiator.
>
> It is wise to minimize the amount of time the oil spends at a tempe=
rature
> less than 180=B0 F, as keeping it warm helps to keep it dry (otherw=
ise, it
> will accumulate water, which is one of the natural products of the
> combustion process).
>
> A coolant to oil heat exchanger is an excellent way to warm the oil=
 up more
> quickly from a cold start, and a properly designed one can also rem=
ove
> about 1/2 or 2/3 of the accumulating heat from the oil in a fully l=
oaded
> engine. An oil to air cooler (smaller than what would be required w=
ith no
> oil to coolant heat exchanger) is still necessary in order to cool =
the oil
> down to 180=B0 F. after the coolant HX , but before it is fed to th=
e
> galleries in the engine. Use of an oil thermostat to bypass the oil=
 to air
> cooler so as not to cool the oil below 180=B0 F. at light engine lo=
ads or in
> cold weather is also a prudent move.
>
> It always takes more detail and more $$$ to do things RIGHT!
>
> Regards, Greg
>
> >yaron

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