The web site information on this stuff is AMAZING! Definitely not inexpensive, but it sounds like THE material for preserving ANY metal that you desire to have a natural, waterproof finish on.
Lower viscosity than water, penetrates gaps as small as one micron... GooD GrieF!
Apparently available in a bottle at an earlier time. I wish it still was. -I've had too many aerosol cans go dead on me.
Sounds like it would be good for an aluminum intake and some cast iron pieces I can think of.
THANKS, Stuey!
NoShortcuts
a.k.a. Charlie Brown
near Syracuse, New York