SBC block filling ?

[Dwight Southerland]

Originally Posted by Reed Granrt

Nope, Muriatic acid will attack the base metal (cast iron). The longer it is in contact with the cast iron, the more it will remove
reed

And the problem is . . . ? Been doing it for years with no problems. You can treat the block, rinse it out and neuetralize it with a couple of baths of strong baking soda solution in thirty minutes and be done. If you are using a concrete-based filler, you can pour it immediately. I have used Por-Rok and Rockite with great success. Phosphoric acid, Rust-Away and similar neutralizers take too long, will not clean nooks and cranies, and require scrubbing the scale off the parent metal, which is impossible to do in the water jackets of a block. If you don't get the scale out, there is a protective boundary layer that prevents the filler from adhering to the block and concrete-based fillers will eventually erode out.

We tried muriatic to "enhance" some cylinder head dimensions once, but it took twenty gallons, seven days and constant applied heat to remove .100". Somehow, that rate of "attack" on the base metal does not concern me.