Then Zink thingies are called "sacrifical anodes" They are on every outboard engine. The idea is the zink sacrifices itself instead of the aluminum. Seems to work on all my outboards so far.
I'm not so sure one would work in your case. Maybe a zink screen in front of a radiator would help.
Big Jim <img src="/forums/images/graemlins/pfft.gif" alt="" />

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