If the parts are removable and small enough to fit in a bucket or small barrel, a long soak in a solution of lye works really well (take the appropriate steps to protect yourself from a caustic solution). You can leave the parts in there for as long as it takes, they won't rust or ablate. Lye only attacks the grease and oils. Its the same active ingredient as oven cleaner. A can of Red Devil powdered lye will do you right up.
I would just throw the parts in lye for two or three weeks, leave them in the sun, and stir them once in a while. A good rinse and paint is all you need after that. Engine manifold paint resembles virgin cast iron pretty well, but does not cure very well without heat.
Last edited by 4ontheFloor; 03/10/2009 5:58 AM.
