"Electrolysis is not a problem unless you are using a conductive fluid like salt water. With distilled water and ethylene glycol, there is no electrolysis."
If electrolysis (galvanic corrosion") is not problem when you use anti-freeze, why is this topic being discussed?
"Plus, anything aluminum would disappear before iron or brass."
Why would aluminum disappear if there is no electrolysis (galvanic corrosion)?
There is no question that aluminum would corrode faster than iron and that iron would corrode faster than brass (as long as they are all inter-connected to each other and in the presence of an electrolyte).
The link above shows:
Less Nobel (more reactive in the presence of an electrolyte)
magnesium,
zinc,
aluminum,
mild steel,
cast iron,
stainless steel (type 410, active),
lead,
Monel,
Muntzmetal,
manganese bronze,
naval brass,
yellow brass,
aluminum bronze,
copper,
silicon bronze,
nickel, and
stainless steel (types 304, 316, and 410, passive)
More Nobel (less reactive in the presence of an electrolyte)
The 1954 235 engine that I am now working on has copper/brass block-casting plugs (they actually are not freeze plugs or expansion plugs) and they look OK. After looking up a little information related to this topic, I now feel more comfortable leaving these plugs in place.
