Hi Folks. In changing the intake on my Ardun the other day I looked
into the water jackets and was pleased to see that there was no sign of
corrosion whatsoever in these 50 year old heads. It would have
gladdened Zora's heart.
I had previously noted, however, that there was a little nibble of
corrosion around the water holes where the head meets the block, and I
am told this is a sort of galvanic electrical corrosion caused by the
proximity of the two dissimilar metals. It is always found wherever you
have aluminum heads sitting on iron blocks. An article in the
newspaper's automotive section recently stated that by 150 to 200K miles
of road service, the aluminum heads used on so many iron blocks today
will be destroyed by this corrosion. The anti-corrosion properties of
the coolant have nothing to do with it.
I'm sure many on the List are perfectly familiar with this type of
corrosion. For our purposes it is not usually significant. But one of
my seasoned Ardun friends recently sent me a couple of plugs with rods
of magnesium pressed in, telling me that it these are put in the water
pumps it will stop the above corrosion. The magnesium will be a
'sacrificial' metal which will corrode to protect the head aluminum.
I have seem confirmation for this from other sources, Anybody on the
List who is an expert on this?? Seems like everybody with aluminum
heads on iron blocks should be doing this.
Regards from ArdunBill in the Great Dismal Swamp, Chesapeake, VA
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