[alfa] Re: 115 spider cooling system saga

[C2slayman@xxxxxxx]

Chris,
    I have close to the same setup on my '89 Spider - upgraded 3 row radiator 
core, electric fan (actually the Bosch unit used to cool the AC condensor 
without the condensor in front of the radiator), stock 190C thermostat and the 
flow restrictor.  This setup stays at 190C without any problems.  On a really 
hot day, it will creep above 190C by a little, but I attribute that to the 
inadequacy of the Bosch fan.  It's intended to be a "helper" and not carry the 
entire cooling load (I've removed my water pump driven fan).  So next summer, I 
will probably install a "real" electric fan.  But it has been more than adequate 
for the past year in the Bay Area.
    I never tried the setup without the flow restrictor.  So I can't say what 
the performance of my system is with and without.  So your problem might be 
related to the missing flow restrictor.  (If you get hit by a bolt of 
lightening, you know it's from Fred up in heaven saying "Put the damn flow restrictor 
in!")  But the thermostat is 190C, so I'm not sure what you are observing is 
all that bad.  It might not overheat under hotter ambient conditions.  You might 
actually be observing the performance of your cooling system in a "thermostat 
restricted" (ie the thermostat is not fully opened) mode.  If the ambient 
temperature were to increase and the coolant temperature rises slightly, that 
might open the thermostat all the way.
    Rich Hirsch's excellent article at 
http://www.geocities.com/motorcity/downs/3837/bypassco.html is good reading if you haven't already seen it.  The 
only thing I'm muddy about is the fact that the thermostat is acutally a "dual 
mode" design that is supposed to BLOCK the bypass hose in the fully open 
position (that's why generic thermostats from Grand Auto or Kragen don't really work 
on Alfas).  So it seems like the function of the restrictor is a little 
redundant - it regulates the circulation when the thermostat is closed (but who 
cares since the radiator is not in the loop) and flow to the restrictor is blocked 
by the thermostat when the thermostat is open.  So I am actually puzzled - 
unless Alfa designed the flow restrictor before they developed the dual action 
thermostat and the restrictor was left in as a "prehensile tail".  But I never 
took mine out for fear of what Fred might do to me if he ever found out!  ;->
    Hope this helps somewhat.
Cheers,
Charlie 


Date: Thu, 13 Nov 2003 15:39:50 -0500
From: "Christopher Keen" <ckeen74@domain.elided>
Subject: [alfa] 115 spider cooling system saga

Hi all,

So I've done some more work on the cooling system in my spider to solve the 
hot-running problem:

- - recored the radiator with a 3-row core
- - new radiator cap (.7 bar)
- - tested thermostat, it's working correctly

The car is still running hot under heavy load - about 195 degrees, but since 
its only 65 degrees outside today, I imagine that on a hot day the car would 
get up to 212ish like it did before. I checked, and the car is missing the 
bypass restrictor. Do other people with electric fans find the restrictor is 
necessary to help keep temps down?

For those of you who weren't there from the beginning, I installed an 
electric fan, and ever since then the car's been running hot under load or 
on hot days (used to hold a steady 180). The gauge has been tested to be 
roughly accurate, and the coolant level is full.

Thanks in advance

Chris Keen
'77 spider
Los Altos, CA
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