Remove rust from used cylinder heads

[qbeanie]

I purchased a set of cast iron heads that were supposedly rebuilt a while back. The heads were installed on an engine and then removed. The water jackets have rust and scale buildup as if the engine may have been sitting for awhile. Other than the rust the heads appear to be in good condition. What is the best way to remove the rust?
Posted via Mobile Device

[mr48chev]

You would have to break them down to do anything to them. Used to be that machine shops stuck them in the "hot tank" with a caustic solution and then pressure washed them now days a lot of machine shops have ovens that they bake them out in. A little bit of surface rust won't hurt anything anyhow but the scale might and it probably took a long time to build up anyhow. The big problem was probably the PO running straight water with nothing in it to prevent the scale and rust.

Cheap way if they aren't surface rusted on the mating surfaces or combustion chambers would be to put them on and run an engine flush though the engine and then either run antifreeze as I and other folks would or at least run an anti rust additive in the coolant.

[qbeanie]

Posted via Mobile Device

[qbeanie]

Thanks your probably right on with the po using straight water. There is no susurface rust and the mating surfaces are clean. I will try scrape/ brush the jackets the best i can. Thankfully the scale releases easily. I was wondering if anyone had used any of those derusting products suceesfully. I want to avoid using muratic acid and the like.
Posted via Mobile Device

[mr48chev]

I don't really think you need to go that far unless it is really clogged up. If you look in the holes that coolant runs though on the surface of the head and see a serious buildup in a lot of them it may be an issue. If there is just a bit of scale here and there It should be ok. If you are really worried take it to someone and have it looked at.