DeTomaso Mailing List: June 2001, Message #87

Pedro Martini <martinirace@yahoo.com> wrote:

> Jack, 
> 
<snip>
> 
> I still can't aford to buy that taller ring gear so
> perhaps 300F oil temp at 6500 Rpm's for 35 minuts
> isn't that bad after all :~)
> Kidding, 

> Pete "The Kid" Martini

I think Pete may have hit the nail on the head: maybe the 300+ oil is
not a 
problem, especially if you're using a good synthetic.

I tried to find some info on the high temp capabilities of
synthetic oil. I found this rather long article in an MR2 archive. Lots
of info.

http://www.mr2.com/TEXT/synth_oil.txt

Among other things it lists Amsoil's effective lubrication range as -65 to
+400F (vs 300 for conventional oil). Also mentioned is the Olds III-D
Test which is a standard test in a 350 in Olds V8 where the oil is run
for 64 hrs at 300 deg. The test is how much viscosity increase there is
due to evaporation and breakdown of the oil. To pass the test an SF oil
can rise no more than 375%. Typical synthetics rise about 10%. Mobil did
a double long test with their Mobile 1 and got 20%. One of the
conventional oils went 96 hrs before it turned SOLID! The article also
talks about the oil temp reductions of up to 50 deg. If Larry, MD, Jr,
etc. were all running synthetics, this has been accounted for in their
results, unless the diesters (e.g. AmsOil) are better in this area. It
also mentions that the oil can provide up to 30% of an engine's cooling.
No wonder there's a problem!

Anyway, I'd say that with a quality racing synthetic, oil temps of up to
350 deg should be reasonably safe. I'll also check with another 4.6L
convertee Neil Rugsegger. Dr. Neil has a PhD in Tribology (Lubrication)
and works for Chevron Labs in Richmond. He should know the answers!

As for submerging a heat exhanger in the oil pan, I'm with Jack on this.
I don't see how you could get enough oil flow through the exchanger. A
heat exchanger requires fluid motion on both side of the equation. Remember
the discussion last week about increasing the water flow in the radiator?

Richard

-- 
Sincerely,
Richard Barkley

To Ski or not to Ski, that is the question!

Richard Barkley
(310) 373-6695 (home), 813-2432 (work)
E-mail: richard.barkley@trw.com (work), rbarkley@earthlink.net (home)
Mammoth Condo 2BR+loft/3Bath - Horizons 4 #186 (760) 934-6758
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