Keep Your Cool
Cooling has been an ongoing issue for our classic and custom automobiles ever since weíve been playing in that arena. The issues can be resolved with high dollar radiators, super pumps, shrouds, and any number of snake oil deals.
are several things that need to be done to insure proper cooling of your
coolant in it. Yep.
Plain water cools better than a 50/50 mix of antifreeze
and water. Debug your cooling system
on plain water (fixing leaks, trying different thermostats, etc.) and then, when
itís all working properly, switch to half water and half coolant for
protection from freezing OR to 25% antifreeze if you want your engine to run
cooler and still maintain some anti corrosion properties in the system.
Remember though that 25% antifreeze protects down to 10 degrees above freezing.
33% antifreeze protects down to 0 degrees. Some drain the coolant from
their cars in the fall before storage. If you live in an area where it's not
that cold in the winter then you'll be fine. Use your head.
Remember though that 25% antifreeze protects down to 10 degrees above freezing. 33% antifreeze protects down to 0 degrees. Some drain the coolant from their cars in the fall before storage. If you live in an area where it's not that cold in the winter then you'll be fine. Use your head.
COOLING SYSTEM. All of it!
The whole deal! Get a cooling system flush
product and follow the directions on the bottle.
A dirty cooling system, and that includes the block, wonít cool as well
as a clean one. Thatís a fact.
to DETERMINE if the water pump is WORKING! Donít
assume anything. Water pumps have a
problem with their impellers deteriorating.
You wonít know youíre missing an impeller or have a problem until
itís too late. Hereís a simple
test. Remove the thermostat.
Bolt everything back together. Start
the car with the radiator cap off. You
should SEE water rushing past the radiator cap opening.
If you donít then something is going on that needs correcting.
that most cars really like a shroud of some sort that directs the flow of air
OUT of the radiator. That is, since
the fan PULLS air through the radiator youíll be MUCH better off using a
shroud. Youíll want the fan about
2/3 of the way BACK into the shroud from the backside of the radiator.
This isnít always possible but itís good to get it as close as you
can to the 2/3 distance. Sealing the area AROUND the radiator helps a
GREAT deal. This forces the air to flow through the radiator. If air is
going around the radiator then it's not extracting heat from the radiator.
Sealing the area AROUND the radiator helps a GREAT deal. This forces the air to flow through the radiator. If air is going around the radiator then it's not extracting heat from the radiator.
caps are important. Yep, they are!
Coolant at 16 pounds of pressure has a higher boiling point than coolant
at 2 pounds of pressure. Laws of
physics apply here. Itís not just
a good idea, itís the LAW. Youíll
run cooler at pressure than you will with no pressure.
Remember to get the correct cap for your application.
Youíll not want to run a 16 pound cap on a system designed to run at 8
your engine without a thermostat (with the exception of our test in #2) is
fallacy. An engine will run cooler initially without a thermostat.
After that IT WILL NOT! Why
you ask? Again,
physics. An engine running
without the restriction of the thermostat in the system (remember, even when
itís wide open thereís still some restriction in the system caused by the
thermostatís small opening) will not keep the coolant in the radiator long
enough for the radiator to Ďradiateí the heat.
That is, the coolant must
stay in the radiator for a certain amount of time to dissipate some of the heat
it has absorbed from being in the engine block.
The coolant is in the block. Itís
hot. It moves to the radiator and
gets rid of some of the heat. If it
moves through the radiator too FAST, without the restriction of the thermostat
body, it wonít get rid of as much heat.
Thermodynamics R Us.
the temperature Ďsettingí or rating of the thermostat the better?
Perhaps. Itís easier to
keep an engine cool than it is to cool it after itís hot.
If we can get our engine to run along at 180 degrees (82 degrees C)
then weíre happy as clams. The
reality is that we will want the engine to run there as an average.
Itís going to run warmer in traffic, stop and go, than on the highway.
Seeing 190 in traffic is fine. Seeing
180 on the road is peachy. Running
at 150 is too cool. Generally,
prefer 180 or so. Arguably 180 is
about nominal. Newer engines run
around 200 to 220 or so but thatís not where we want our street rod (unless itís an
L1 crate engine or the like) to run. Our
TR6 is very happy at 170-180. The
Spitfire will like running around the same temperature.
Your small block Chebby or RB 440 Mopar will be joyus if you set it up to
run around 180 degrees.
degree thermostat is probably a good place to begin.
That is, the thermostat will open when the coolant temperature reaches
160 degrees (71 degrees C). This
allows the coolant that is ďtrappedĒ in the engine block to start to FLOW
through the radiator and have itís heat removed.
If you watch your temp gauge carefully youíll see, just as you reach
160 degrees, the temp will DROP 5-10 degrees or so.
That sudden rush of cooler liquid thatís been sitting in the radiator
will drop the temp a bit. Of course
it will go back up as things run along but thatís normal.
If you wish, you can test your new (NEW) thermostat by putting it in
water on the stove. Use the candy
thermometer to see at which point the thermostat actually opens.
A new, 160 degree thermostat will open within 5 degrees of itís rated
temperature (usually right on the number).
Oil, or making water more wetter than it comes from the factory. Does this stuff
work? Depends on who you talk to.
Some people claim thereís nothing to it.
Some people claim itís the beeís knees.
Iíve never used the stuff and, therefore, have no basis for comparison.
Try it if you like, donít
if you donít. A properly
functioning cooling system wonít need miracle chemicals to make it work.
If itís broke youíre not going to fix it with different chemicals.
The key to water's ability to extract heat is it's 'surface tension'. The
better it adheres to the walls of the cooling passages the better it will pull
that heat out and carry it to the radiator.
The key to water's ability to extract heat is it's 'surface tension'. The better it adheres to the walls of the cooling passages the better it will pull that heat out and carry it to the radiator.