Date:         Fri, 9 Feb 96 10:27:35 PST
Sender:       Vanagon Mailing List <vanagon@vanagon.com>
From:         Dave Kautz <dkautz@hpsidms1.sid.hp.com>
Subject:      Max Oil Temps. - a reference!

 During the 15 months or so that I've been following vanagon@lenti the
 question of what is a maximum safe oil temp has come several times, with
 anecdotal and speculative suggestions as to what it might be.

 I've been reading a book a a co-worker loaned me called "The Sports Car - 
 It's Design and Performance" by Colin Campbell. There are several pages
 devoted to the discussion of lubrication from which a couple of remarks may
 be of interest: Bearing failure is "anticpated" when oil temperature at 
 the bearing reaches 340 degrees F. However, the oil temperature at the
 bearing is higher than what is measured in the distribution gallery by
 as much as 85 degrees F.!

 Subtracting 85 from 340 gives us a maximum gallery temp. of 255 degrees F.  
 HOLY SHIT!!, you say, I've taken my engine higher than that!

 But there's a catch for most of us, we don't know what the oil temp in the
 gallery is - most folks have mounted their temp sensors in the sump and
 are measuring the temperature of the oil BEFORE it has gone through the
 cooler. Does anyone know what the temperature drop is across the cooler?

 Eugene Palmer had a setup on his full-tilt-boogie engine which had a sensor
 IN a cooler, I think. Are you out there somewhere, Eugene??

 One other caveat. This book was published in 1978, oils supposedly have 
 gotten a bit better since then in their resistance to temperature. Perhaps
 we have picked up some margin. I'll repeat what the Pennzoil
 technical rep. said for those of you who haven't heard it before: 230F
 is the "correct" oil temp and oil should be changed if it has taken 
 excursions in excess of 300F.



 Still gaugeless -  "ignorance is bliss",

 Dave