Sometimes I am not good at measuring, but about 1/4 1/2 cup to a gallon. I usually rinse with water. On engine blocks , As soon as I rinse,oil the cylinder. I have never had a problem with it turning aluminum , But then I don't allow it to just sit there. This stuff works in minutes not hours.
I use it to wash dirty rags, car, boat, trailer, dishes, Tools ,vinyl siding, wood fence, You name it.
Between that and baking soda and Borax. I never buy any cleaners.
You can buy all three for about $10 to $15 depending where you buy it.
Use parts cleaning brushes to reach those hard to reach places.