COOLING

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From: monzamiler_REMOVE_174522_THIS_@yahoo.com


Here are a few things I have learned over the
years on cooling systems. Though most of it pertains to
early Ferrari's, I have successfully applied these
techniques to Vega V8 Conversions as well. One of the first
things to do is clean the cooling passages in the
cylinder block. I have received many of them back from 2
trips through a hot-tank that were still loaded with
sediment. The pressure washer at the local car wash is a
great tool for this. Run a drill bit through the
cooling passages around the spark plug holes. These are
often clogged with rust, gasket material or casting
flash. It is also a good idea to clean up all the
cooling passages in the head while you are in there. I
take the cover plate off the back of the water pump
and cut out a steel disc that covers the vanes on the
impeller then pop-rivet it into place. This is similar to
many of the high-volume water pumps now available on
the market but costs much less. Next is the biggest
cause for overheating: Too Much Coolant. 50% should
ONLY be used where your climate dictates it. The
preferred ratio is 30% to 40% and I keep mine around 30%
year round here in California. I have seen as much as
a 30 degree increase in engine temperature by
raising the coolant concentration just 20%. You should be
running at least a 15 pound pressure cap and an
overflow-recovery system. Mix the coolant with a Hydrometer in
separate containers using distilled water. Minerals in the
water in many parts of the country can cause high
concentrations of scale and erosion of the head gasket material.
Generally speaking, 1 gallon of Prestone should yield 4
gallons of coolant when mixed properly. However, be sure
to have adequate low-temperature protection for your
winter climate! It never gets below zero here and 12
degrees above zero is the worst freeze we ever
encountered. With summer driving, you will need to adjust this
concentration. Timing should be advanced as much as possible, at
least 10 BTDC on most small block Chevrolets and I
often run 20 BTDC @ Idle on many of my engines with
long duration camshafts. Total timing should be held
to 34 to 38 degress total. Check your spark plugs
for any signs of a lean mixture and jet accordingly
keeping in mind the heat range of the plug, which should
be close to OEM recommendations or colder. I always
use a 7 Blade Cadillac Fan with a 454 Chevrolet
Thermostatic Clutch and a properly fitted shroud. The fan
should be very noticeable on start up and then quiet
down, but should become very noisy again as the
temperature heats up. I only buy them new from GM. None of
the "Chain Store" variants seem to work properly or
last very long either. I use a full sized electric fan
on the front of the radiator with a Honda Thermostat
in the lower tank set to activate the fan at a
temperature of around 220 to 230 degrees Fahrenheit. With the
vehicle prepared in this respect, I am yet to have any
overheating woes with one of my conversions. I hope this
information is helpful...Robert


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