RE:How hot is too hot?

[Hirsch <Catenary@xxxxxxxxxxxxxx>]

John Christensen wrote:
 =

>> I recently installed an electric cooling fan kit from Alfa
Heaven in my '69 GTV(w/2.0L engine). The fan is a 12" unit
rated at 1429cfm and comes with an adjustable temperature
switch that I have set to come on at ~185 deg. The highest
temperature I ever recorded with the engine-driven fan was
~195 deg and the car typically was ~185 deg in normal traffic
situations -- including 90 deg days. <<
 =

>> This morning I was stuck in stop and go traffic for nearly
1/2 an hour in very cool weather (about 40 deg). After approx
20 minutes of this Seattle gridlock, the temperature gauge
shot up to around 210 deg. The fan was working at the time, but
I'm not sure this is an acceptable figure particularly given
how cool it was outside. I plan to rebleed the cooling system
to make sure I didn't screw that up, but I would appreciate any
opinions on what is acceptable in this situation and when I
should begin to worry. BTW the car has a new radiator, water
pump and fresh coolant (50/50 mix).<<

This is too hot. I can think of a couple things to check:

1) Make sure air is bled out of the system via the bleed
screw near the thermostat.

2) Is the correct thermostat fitted? That is, the one with
the bottom plate that closes off the bypass hose when the
car is warm.

3) When does the elect fan turn on? Did it turn on at 205
deg F? If so, you may want to reposition the fan thermostat
so it's more sensitive to the rad temp and/or turn down the
setpoint. Alfas with factory elect fans have the fan
thermostats set to come on at 185 deg F, but this is with
the thermostat in direct contact with the coolant. If your
fan thermostat is just contacting the rad metal skin, you
may need to set it lower. Also, you didn't mention where
the fan thermostat is mounted, but it should really be near
the bottom of the rad, since you want the fan on ONLY if
normal air flow thru the rad is insufficient to cool the
coolant. (The gauge temp sensor is at the top of the engine,
at the engine outlet, as it should be.)

4) I assume you're using a pusher-type fan fitted in front
of the rad. Is the polarity of the fan correct? Is the fan
mounted close enough to the rad so the air is forced thru
the rad?

BTW on the subject of installing an elect fan in an older
car, there is an article on this at the website:

   http://www.catenary.com/victor/isaluti

To find the article select "Feature stories," "Cooling," and =

"Installing an Electric Cooling Fan in a Spider."

Good luck,

Rich Hirsch
'87 Milano
'78 Spider
'67 Duetto
'66 Sprint GTV <- Catdaddy
Editor, i Saluti, St Louis AROC
Website: http://www.catenary.com/victor/isaluti

------------------------------