Re: Oil Coolers

[QSHIPQ@aol.com]

In a message dated 97-10-18 08:35:11 EDT, you write:

> 100C IS TOO cold...... should be at least 230-250C and those are
> conservative figures....
> Avi
> 
<< > >
 	230 to 250c is 446f to 482f way too warm oil starts to break down about
 300f. Remember 100c = 212f.
 turbo
  >>
Agree with turbo here.  Avi, the common rule of thumb these days is to keep
cars at 100c, then open every port cooling thermostat to leave it there.
 Audi is no exception, in fact one of the first to design that parameter.
 All audi applications with oil coolers use a 100c OIL thermo.  since 212
boils water, you have eliminated the moisture in the oil.  I'm sure Avi just
has his C and F backwards above, but 120c is considered max high, and by 140C
(250f) you should get home and change the oil.  I would argue, by 300f you
prolly already inherited another problem, adding lots of oil does mean
changing it I suppose:)

Running a cooler thermo in oil on an audi can actually cause blowby, since
the block isn't getting warm enough to round out the cylinders bores, btdt,
especially in winter.  The better system is to keep the 100c thermo, and go
BIG on the cooler.  Pegging the oil at that temp keeps moisture out, and the
motor at what audi considers optimal temps.  I have ridden in several audis
that have this mod, and amazingly, the temp pegs 100C and stays there always,
regardless of boost and hi ambient temps.  

BTW, those with 44 bodied cars can vent the stock oil cooler to a convenient
low pressure zone (at a cost of about 3bux) and get more effective airflow
thru the stock unit = increasing its efficiency.

Scott
'87 5ktqwRS2
'87 5ktq
'86 5ktqw
'84 Urq