No discussion on coolants would be complete without a mention of our old
enemy cavitation. The radiator normally gets the worst damage from the
crud buildup and the Gano works well at controlling this problem in
conjunction with proper coolant chemistry. The typical damage to the
aluminum front cover is a combination of the galvanic activity between it
and the steel bolts and cast iron, and the cavitation produced by water
pumps operating above their design limits. The more RPM the pump runs, the
more you need to pay attention to the design of the pump impeller. The
cheap sheet metal impellers are typically the worst offenders but the
straight blade cast iron impellers aren't much better. A pump with poor
high speed flow characteristics will result in significant wear to the pump
and aluminum cover as a result of the abrasive nature of the cavitation
bubbles. Performance engines should always be fitted with a reverse blade
impeller to minimize this problem.
Tom
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