Calcium and rust the orange ones are freshly pulled the one that's white has beer. Chipped and wire wheeled
I talked with my brother the water expert. The Rydlyme will work on the calcium. HOWEVER, you will need to add a defaming agent (available at pool or hot tub store) as the breaking down of calcium will cause hydrogen and carbon dioxide release which will cause the foam. Also, you will need to remove the thermostat or it will capitate and eat itself up. After you get the desired results, you will need to do multiple flushes to get rid of the residual Rydlyme as it will destroy the antifreeze.
Check out the other stuff I suggested as it will work the same way, still needing the defamer and no thermostat.
With either of the chemicals you use, if its possible to flow the water without running the engine it will work. In any case as temp of the water increases so does the chemical reaction to convert the calcium. Be careful as if it gets up to op temp it becomes detrimental to aluminum. Recommended max temp 120F will make everything be happy.