rust on my cylinder head

[pdxxs650]

I am doing my first rebuild and I put the cylinder head in about two inches of simple green- just enough to soak the combustion chamber. I read some posts talking about it, but only after did I see posts saying not to use it on aluminum. I used half diluted. So I rinsed it in water and dried it and noticed little specks of rust. So I brushed it and covered it with motor oil. Also I see a little rust on valve guides. Did I totally screw up on this? Any suggestions?

 

[XSLeo]

The acid in some cleaners will turn aluminum black, not a pretty black, just black. If left long anough it can eat the aluminum.
I don't know what acids may be in Simple Green.
The combustion chamber is a steel insert with the head cast around it. The valve guides I thought were sintered bronze, if rusty then they maybe sintered steel.
UIf just a few tiny spots of rust, I wouldn't worry about it.
Just clean it off with a wire tooth brush. Or as you did oil it.
Leo

 

[jd750ace]

Phosphorus and chlorine compounds are the most common harmful elements to aluminum in cleaners. If you are trying to remove carbon deposits, good old ammonia is hard to beat, and won't attack your metals. We used it all the time to "de-coke" hot sections of turbine engines where a fuel nozzle would get blocked and slobber instead of spraying, and the droplets cook instead of burning and creating gas pressure. Looks like the crap in the bottom of a coffee pot when you forget to turn the burner off. Ammonia works on THAT too, BTW.

 

[pdxxs650]

Do you mean like Windex another type of ammonia product? Soak the whole cylinder head? I need to clean the exhaust valve guides, the simple green did remove the carbon from the combustion chambers.