Date:         Wed, 2 Oct 2002 19:30:11 -0400
Reply-To:     "G.M.Bulley" <gmbulley@BULLEY-HEWLETT.COM>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         "G.M.Bulley" <gmbulley@BULLEY-HEWLETT.COM>
Organization: Bulley-Hewlett
Subject:      Re: Some Clarifications and Additional Cooling System Comments
In-Reply-To:  <Pine.SUN.3.96.1021002183911.18014A-100000@grex.cyberspace.org>
Content-Type: text/plain; charset="us-ascii"

Head temps in an air-cooled are typically 325-350 (F). 375 is hot. 400
is reason to pull over and high-idle. >400 means dropped valve seats.

Head temp can rise and fall far faster (matter of seconds) than oil
temp. In winter on our 1976 you could climb a big hill and see 380
degrees, reach the peak and start down the other side and see 150
degrees within a minute or so of closed-throttle decent.

Oil doesn't cool the heads in any measurable sense in an air cooled, in
fact it is the only region of the motor that doesn't really shed heat to
the oil, almost exclusively to the air. Oil temps of 180-220 are normal.
240 is a bit toasty, ease off at 250. Hit 275 F and I'd pull over to
cool. Hit 300 and you better change the oil once the thing cools down.

Bringing your ideas to life,

G. Matthew Bulley
Bulley-Hewlett
Business: www.bulley-hewlett.com
AIM = IExplain4u
Phone: +1.919.658.1278


-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@GERRY.VANAGON.COM] On Behalf
Of David Brodbeck
Sent: Wednesday, October 02, 2002 6:45 PM
To: vanagon@GERRY.VANAGON.COM
Subject: Re: Some Clarifications and Additional Cooling System Comments

On Wed, 2 Oct 2002, westydriver wrote:

> my air  cooled will put the oil temp needle all the way over on the
> high passes.  30 in second in my poor little 82westy.  in the spring i
> am redoing the oil cooler with a blower fan and possibly a mister.  a
> little thing that a lot of WC people dont think about is that their
oil
> is going way up in temps as  well.

Hmm...The oil and the water are both going through the hottest part of
the
engine at some point (the head), and there's an oil-to-water oil cooler.
I'd expect the oil temperature to stay pretty close to the water
temperature.  I'm well aware that conventional wisdom can be wrong in
these sorts of situations, though -- anyone instrumented both and have
some answers?

             _ _
  __ _ _   _| | |  | David M. Brodbeck (N8SRE)              Ypsilanti,
MI
 / _` | | | | | |
+-----------------------------------------------------
| (_| | |_| | | | @ cyberspace.org
 \__, |\__,_|_|_| "There is something ironic when the developers name
 |___/             housing development after what they bulldozed to
build
                   it, but I think you have to allow some latitude in
                   naming, so that not every street is called "Suburban
                   Drive." -- Jan Wolter