Date:         Wed, 20 Mar 1996 11:06:11 -0800 (PST)
Sender:       Vanagon Mailing List <vanagon@vanagon.com>
From:         David Schwarze <des@teleport.com>
Subject:      Re: Overheating symptoms?

Rick Gordon writes:
> 
> I'm going to argue these numbers a little bit - my opinion only, nothing
> personal. The advice is sound though - you'll learn a lot more about the
> engine
> under load with gauges installed.
> 
> With these stats you'll never get over any mtn passes, at least not in the
> summer. The heads are going to get hotter than 350F, hell that's their
> normal operating temperature! If you're climbing a mtn with it, start
> worrying over 550F. Oil temperature can arguably get hotter - water doesn't
> boil out until 210F. Oil pressure will get lower as the oil temp rises.
> Also the head temp sender *will* mount in the spark plug hole in a 1980
> engine, and its pretty much the same as the 78-83. The head temp gauges are
> kind of pricey - if you only get one, put it on #3 cylinder.

I appreciate your response, Rick.  I agree that the heads get hotter
than 350 - that figure was based on having the sender installed in the
stock sensor location, which is tapped into the side of the head.  My
engine indicates around 250 under light load, and goes up to ~325 going
up long hills.  Listmembers have reported much higher temps at the spark
plug, and I believe it.  What is important though is being able to see
the temp increase over "normal", which works no matter where you locate
the sender.

As for the sender, I am using the VDO sender and there is no way it will
fit.  The spark plug is recessed and there is maybe .050" clearance
around the plug.  You can mash the sender in there but there is no way
it will lay flat.  This is for stock heads and Bosch plugs.  If one were
to have the spark plug hole flycut a little it may fit, or it may fit if
you use a different sender, or different plugs.  But why mess with it?
There is a nice place to mount the sender already tapped into the head
which won't interfere with the spark plug.

I should elaborate a little more on oil temp too, I guess.  I mentioned
not driving the bus hard if the temp goes over 230.  I didn't necessarily
mean to pull over and let it cool at that temp.  My opinion is that if your
gauge is reading 230 the oil is probably more like 280 at the bearings,
and under an extreme load I wouldn't want to count on the oil protecting
the engine at that temp.  If you're using synthetic oil, maybe higher
temps are permissable.  My engine only hits 210 degrees going up the
grapevine (a 4,000 ft 6% grade).  If you are seeing temps of 250+, it is
my humble opinion that your engine is overheating.  :)

-David

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David Schwarze                   '73 VW Safare Custom Camper       (Da Boat)
San Diego, California, USA       '73 Capri GT 2800                (Da Beast)
e-mail: des@teleport.com         '87 Mustang Lx 5.0          (13.986@100.81)
http://www.teleport.com/~des     '93 Weber WG-50                  (Da Piano)
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