Conference napalm::musclecars

Well, I finally got the exhaust system installed on the Vega and had a chance
to put some miles on it this weekend.  As with project like this, there are a 
few "bugs" to be worked out, the worst of which is cooling problems.

This sucker runs hot!   It is basically undrivable in traffic and even gets hot
(230 deg.) when no stopping for traffic is required.  I need to start looking
at what to do to to cool this thing.  Right now it has a flex gan on it with no
fan shroud.  Adding a shroud and/or electric fans may help in low speed 
operation.  Adding a lower temp. thermostat (160 deg. now) or a high efficiency
water pump will only help if the coolant is getting cooled enough in the 
radiator.  The radiator is a 4 row in which the core measures 12x21.  Ther is 
not any room to run a wider or higher radiator and it only clears the fan by
1 inch.

Do you folks have any ideas on what I should try?

Thanks,
Mark

    
        A recent article in Hot Rod or Popular Hot Rodding had exactly just
    what you are talking about. the only modification they made was to add
    a fan shroud....it dropped the hot side temperature by 25 degrees, with
    NOTHING else done except the added shroud. Look into this before you
    blow money on something that might not work. I would bet a bone yard
    has what you need. good luck!
    
    -john

    Hi,,,
    
    Also if you are running with the radiator's internal tranny cooler
    add an external one... That dropped my car's temp by 10-15 degrees...
    
    
    			Brian...

I read the article in Hot Rod and realize that a shroud will make a difference
at lower speeds.  They also used a Brassworks water pump on it which helped out.
The Vega shroud is a 2 piece unit and I only have half of it right now and have
not been able to find the other half at the bone yard.  

The trans cooler is an external unit.  There isn't one in the radiator.

    
      Mark,
    
    I agree with John, get the shroud on it first...  From my experience,
    it will not only help the low speed cooling, it will help at all 
    speeds.  You will probably have to remove the flex fan, and
    install a fixed blade fan.  From memory, I think you may not have enough
    room to install a clutch fan.  I have had nothing but problems with flex
    fans.  Both heating, and breakage.  I haven't personally tried the
    electric fans, so I can't offer any opinion on them.
    
    Tom
    

      When I bought my Grand Prix I had a ton of cooling system problems.
    What finally solved the problem was a bunch of things that helped
    a little at a time.  Here is what I did.
    
    Took out 195 degree thermostat and put in 160. (This made the car stay
    cooler a little longer, but it would still heat up in traffic.)
    Replaced factory clutch fan with cheap flex fan.( this made little or
    no difference)
    Fixed bottom of radiator shroud where it had come apart.
    Put in a brand new 4 core radiator. (lowered temp about 10 degrees)
    Added electric fan in addition to flex fan. (lowered a couple more
    deg.)
    Replaced cheap flex fan with a good quality flex fan.  (much better
    than the cheap one.  If you go for a flex fan spend the money).
    Made sure cooling system has no air pockets. (for some reason I had
    this problem)
    
    All these changes I did over time and the car went from 225-230 degrees in
    traffic to about 190.  Interestingly enough it never boiled over.
    
    Rich
    

    One thing perhaps overlooked: you mentioned your car ran hot even when
    driving at normal speeds. At that time there should be more than
    sufficient air flow to cool that engine so:
    		A: the timing is to Retarded or advanced. If it starts
    		   by turning freely without a fight(even hot) then it
    	           is likely too retarded. Adding a few degrees to your
    		   mechanical advance and let it run in the driveway, see
    		   what happens!
    
    

Most GM engines run with manifold vacuum to the distributor.  If you apply 
ported vacuum to the distributor on a car that wants manifold vacuum it'll 
overheat at the slightest provocation.

If the tune-up procedure states to remove the vacuum advance hose you can be 
fairly certain that the motor wants manifold vacuum.

Manifold vacuum should cause the motor to increase in speed dramatically when 
the hose is re-connected.  Ported vacuum will have no effect on idle speed as 
there's no vacuum present.

Manifold vacuum activated advance units that are improperly connected will 
almost always result in severe overheating at idle.

Check the spec sheet

The vacuum advance is connected to ported vacuum.  This is the way that this
distributor is supposed to set up.  It is a non computer HEI that I am using.

I am running 13 deg mechanical advance, 8 degrees vacuum advance, and 13
degrees initial advance.  I have the correct balancer and timing tab for the 
year of the engine and I checked the accuracy of it when the cam was degreed.

I think that the timing is ok.

The engine fires right up when hot.  No matter how hot (unless it has the
vapor lock blues).  I am however not running a stock starter.  In anticipation
of hot start problems, I decided to use one of the high torque mini-starters.

Thanks for taking the time to make suggestions.

When the improved version of the Vega emerges from the garage in the spring,
I am considering having a 5 row radiator built for it and using pusher electric
fans.  I really need to run a core larger than 13"x20"x4row but, there's no
room in there.  In talking to several people with v8 Vegas, this is normal.  
They all seem to have this problem.

Mark

    Has anyone yanked there mechanically driven cooling fans in exchange
    for electric ones?  Aftermarket ones go for around $100 that I've seen.
    Has anyone used electric ones yanked off of a late model car from a
    junkyard?  Any experiences you'd care to relate?
    thanks,
    Matt

    Matt, the aftermarket ones are easier to install since they're
    designed for 'universal' applications. The factory ones usually have
    every mounting point on a different plane which makes them very
    difficult to install on another car. 
    
    They're also very difficult to find in one piece at a junkyard. If the
    nose isn't hit, the yard won't sell to fans from it. They get
    lots-o-bucks for a complete nose. If the nose is hit hard enough to
    render the car a total loss, the fans are probably part of the water
    pump. :-(
    
    Summit Racing lists them in their catalog at a decent price.
    
    Harry
    

re: .10

I installed one when the viscous clutch went bad on my Mazda.  The fan went
in just fine. However, the thermostatic control bulb required that you
route the capillary tubing into the upper hose, bending it around to come
out of the neck thru a rubber thingy that sealed it all up.

Needless to say, I was skeptical, but it did seal. I'd have preferred
a more permanent installation, but that's all I could get at that time.

Operation was fan-tastic [ ;-) ]  I got caught in stopped traffic one summer
on Rt 287 in NY near the Tappan Zee and switched on the fan (override).

The temp gauge dropped almost immediately to the range it used to cruise
at and never faltered.  Most of the ride from there on was getting
around all the other cars that had overheated.

Chris

Depending upon how what you are trying to cool, there are better fans available
that what Summit or the local speed shops sell.  I looked into electric fans as
a possible solution to the cooling problems with my Vega.

There are some companies out there that make fans that will really move some air.
The fans that I was looking at running (a pair of 10") would move something like
2500 cfm for the pair.  The ones that you get from most suppliers, in that size,
are only capable of moving about half that amount.  This company (can't remember
the name) also has larger size fans if you need them.  The only drawback is that 
they need a good charging system to run them.  The 2 10" fans will draw something 
like 24 amps.

Mark

    
    
    	I've got a Flex-a-lite Black Magic M150 electric fan for sale 
    in case you're interested. It is the one as seen in Summit. It is like
    new; I used to have it on my Landcruiser.
    
    	I'll give you a better deal than Summit will! Send me a mail
    message if interested.
    
    	Dave

    re: 10.
    
    i have tried a 16" aftermarket electric in my '67  427 vette.  the
    thing would overheat in less than 5 minutes just sitting in the garage. 
    i went to the stock system of a clutch with 7 blade fan and it rarely
    goes over 190 degrees now.  i can even do desert runs in 110 degrees
    without any problems.  i have this fan for sale if anyone is
    interested.   made by DERALE= $75.00 still new.
    
    steve 

I swapped in a flex fan in place on my thermostatically controlled clutch fan
and lost one whole mph in the quarter mile boogy.  My hope was to free up power
and increase low-rpm cooling.  The cooling part worked, but the cost in power
was unexceptable to me.  I double checked my dragstrip findings with my
Vericom and found that back to back runs - flex fan then stock clutch fan - 
yielded 5% faster 35-55mph tests with the clutch fan.  

This was a flex-a-lite #1518 semi-flex reverse-rotation fan.  Perhaps a more
flexable model would work; this jobber was rated to 10,000 rpm and was pretty 
stiff.

Eric

    Eric,
    
         I remember a fan shootout in one of the rags a while back
    and their findings coincide with yours. The most power was observed
    without a fan (running an electric I would assume) and second place
    was with a thermo clutch fan. My vague memory says that the flex fan
    might have come in third only to leave the stock style five blade
    in last.
    
            Dean

    I've still got that article someplace.  The thermostatically clutched
    fans showed almost no loss over no fan.
    
    The tests were all done on a dyno as I rememeber.  I'll see if I can
    find it.
    
    /tb/