Date:         Fri, 25 Sep 2015 19:21:57 -0700
Reply-To:     Stuart MacMillan <stuartmacm@GMAIL.COM>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         Stuart MacMillan <stuartmacm@GMAIL.COM>
Subject:      Re: Oil Temperature??
In-Reply-To:  <6327A58F-14D6-4465-A246-CF1FDC02F76D@comcast.net>
Content-Type: text/plain; charset="us-ascii"

Well, the base stock is physically thicker at any temp, but it's pretty
minimal in raising pressure at idle when hot.  I just feel better with an
extra psi or two on my worn engine.  A good cooler increases viscosity.

It's all about kinetic and dynamic viscosity.  For more than you likely care
to know, see http://www.machinerylubrication.com/Read/411/oil-viscosity

I was a chemist in a previous life, and tribologists were once clients of
mine.  Fun stuff.

Did you know that the best natural lubricant ever discovered is whale oil,
and tribologists have been trying to synthesize something that has its
properties for decades?

Stuart

-----Original Message-----
From: OlRivrRat [mailto:OlRivrRat@comcast.net]
Sent: Friday, September 25, 2015 6:41 PM
To: Stuart MacMillan
Cc: vanagon@GERRY.VANAGON.COM
Subject: Re: Oil Temperature??

        20w50 is only Thicker than 15w50 when they are Cold which is when
they Need to be Thinner ~

When they are Hot they are both 50s ~

                                                        ORR ~ DeanB


On 25 Sep , 2015, at 6:13 PM, Stuart MacMillan wrote:

> Try Red Line 20w-50 synthetic oil.  It gives me a 1-2 psi boost at all
> rpm over 15w 50 because it is physically thicker.  I'd love to see 30
> @ 4000, I'm closer to 25 when hot.
>
> It's the idle pressure that really tells you what's going on with the
> bearings.  Below 8 when hot means it's time to plan for a rebuild or
> conversion.
>
> Stuart
>
> -----Original Message-----
> From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On
> Behalf Of Robert Clemmer
> Sent: Friday, September 25, 2015 1:17 PM
> To: vanagon@GERRY.VANAGON.COM
> Subject: Oil Temperature??
>
> I have a 91 2.1 WBX that just turned 300K miles on this past trip to FL.
> The oil pressure is fine until the oil temperatures start to go on the
> north side of 220 then it starts dropping proportionately with oil
temperature.
> Oil temperature starts climbing proportionately with outside air
> temperature when the temperatures are above 85.  When it is 95 or
> higher outside my oil temps can go 240-250 and pressure will drop to 30
psi at 4000 rpm.
>
>
>
> Those of you have that have installed external oil coolers, how
> effective have they been?  What kind of temperature drop can I
> reasonably expect if I decide to install an external cooler when I
> pull this engine to "freshen it up"?
>
>
>
> Thanks for your comments, BobC