[Healeys] Fw: Thermostats

BJ8 Healeys sbyers at ec.rr.com
Thu Aug 26 15:30:29 MDT 2010


That's exactly what I did today, Dick.

Around noon, I cranked up the BJ8 and let it idle in preparation for a
40-mile roundtrip for lunch with some Healey friends.  The ambient temp was
86 deg. F.  when we pulled out of the driveway, the gauge was showing just a
hair above 190.  By the time we drove a mile, the gauge said 212.  It held
constant at this temperature for 10 miles of driving without stopping until
we got to the ferry.  After a 20-minute ferry ride, we drove another 10
miles with the gauge back at 212.  During the trip home with slightly cooler
ambient temp, the gauge made it to 212 by the time we got to the ferry and
was at 212 when we got home.
I pulled the sleeved thermostat out of the car and drove without a
thermostat another 10-mile round trip with 5-miles out at 55 mph without
stopping, at which point I had to stop for a light and make a U-turn.  The
gauge registered a bit over 190 during the outbound trip, but climbed to 212
at the light and stayed there for the 5-mile trip back home.  At this time,
the ambient temperature was 79 deg. F.
To me, this proves at least that running without a thermostat does not by
itself make the car run hotter.  On the contrary, I am sure that if a
thermostat had been in place for the second trip, the car would have reached
212 much sooner than it did.  Until I got to the light, I was sure that the
gauge would stay at around 200.
At home, I tested the sleeved thermostat in a pot of water on the kitchen
stove, and monitored it as the water heated up.  The thermostat is rated at
86 deg. C (186.7 deg. F).  It began to open at 86 C and was fully open by 98
C as measured by a candy thermometer in the water, and measuring the
physical dimensions as the bellows expanded and the blanking sleeve rose.
It was a bit difficult to measure accurately because the thermostat visibly
closed very quickly when it came out of the water.

Anyone have a plain blanking plate they want to test?

The next step will be to test the gauge for accuracy, as soon as I have time
to pull it out.

Steve Byers
HBJ8L/36666	
BJ8 Registry
Havelock, NC  USA

-----Original Message-----
From: healeys-bounces at autox.team.net [mailto:healeys-bounces at autox.team.net]
On Behalf Of Dick Matson
Sent: Thursday, August 26, 2010 3:42 PM
To: AustinHealey List
Subject: [Healeys] Fw: Thermostats

So .  .  .  regarding your heating situation Steve the experiment to
temporarily remove the thermostat and road test the car could tell you
something about the roll your thermostat might be playing - or not playing.
Perhaps you've done that - long ago already.


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