Originally Posted by OneMoreTime
Magnaflux is used on iron heads the dye penetrate on aluminum heads though the dye penetrate will work on both..Some heads have a pipe plug instead of freeze plugs..in any case clean the coolant passages as I am convinced the coolant passages can be plugged in some cases leading to overheat issues..Your methods should work fine..
ahhh.. okay I was wondering since you cant magnetize aluminum. Should I switch to a small steel shot for my blast cabinet or would a glass bead or silica media continue to work? The 20/40 seems to eat away pretty good which I don't mind except for the gasket surfaces.