[Healeys] Engine Temperature Info ??

[BJ8 Healeys]

Al, your radiator shop may know a lot about repairing radiators, but they
obviously don't know much about thermodynamics of heat flow.  Increasing the
coolant flow rate through the radiator will increase the heat transfer rate
between the coolant and the radiator, not reduce it.  There are other
considerations that limit how quickly the coolant should flow through the
radiator, but in general increased coolant flow equals increased heat
transfer.  It's similar to the air flow rate through the radiator.  The
faster the air flow, the more heat transfer takes place between the radiator
and air.  You get better cooling while underway than you do sitting still,
yes?

Everyone knows that I know BJ8s and not much else, but I assume the tricarb
originally used the same sleeved thermostat and basic head design as the
BJ8s.  The sleeve was intended to rise and block the coolant bypass in the
head as the thermostat opened with increasing coolant temperature.  The
bypass is there to allow the coolant to flow back through the head instead
of to the radiator for faster engine warmup.  Running without a thermostat
would allow this bypass channel to function all the time.  The factory parts
manual identifies a "blanking sleeve" to be used instead of the thermostat
for hot countries because in the absence of the thermostat the blanking
sleeve closes off the bypass. 

As long as the gauge is accurate, 190 deg. at cruise on a warm day is
normal.  Using a lower temp thermostat can cause the engine to run too cold
in winter.  I believe 160 degrees is too cold. 

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 Al Malin
Sent: Friday, August 03, 2012 3:15 PM
To: Healey List
Subject: Re: [Healeys] Engine Temperature Info ??

I was told by a radiator shop that a cooling system needs the restriction
provided by an open thermostat. They say, without the restriction the flow
though the radiator is too fast for effective heat transfer.