I am trying to make sure the block is cleaned out.
Would putting 3 gallons of vinegar be too much or should reduce it with a gallon or two of distilled water?
I will be running 50/50 after the block is good and clean.
I've used straight vinegar, no dilution, with moderate success. The flushing tool found on the forum is also very useful, I was able to dislodge more gunk than just the soaking alone would do. Keep in mind if you don't properly flush the system, the rust and debris has nowhere to go and will only cause more problems.
I think it would be too much. I don't think a Model T holds 3 gallons. Does it?
With 3 gallons of vinegar you will need to use 10 gallons of "Baking Soda". If you don't stop the acid in the vinegar you will have a BIG mess. Don't ask how I know!
Baking soda and water mix?
One box to a gallon?
As I recall I used 2 gallons. Costco sells 2 gallons for a few dollars.
My '14 held about 2 gallons when I did it a couple years ago. I think a black radiator car might hold close to three. I used straight vinegar and then flushed it with water. No issues.
One interesting thing, I left the vinegar sit in my rusty metal drain pan for about a month before dumping it. The formerly rusty drain pan is shiny clean now.
Straight Vinegar has about a 5% acidity which is great for removing scale build up. Just rinse it real good when you are done flushing.
Why not "CLR"?
Tim I can but 6 gallons of vinegar for the same price as 1 bottle of CLR and IMHO it works better!
This subject has as much controversy as what oil to use.
For cleaning a block I always use phosphoric acid, the active ingredient in CLR. Vinegar (citric acid) will do a good job in removing lime scale but not much rust scale. The phosphoric acid will dissolve Iron oxide and leave a phosphate coating on the clean iron. It neutralizes well with clear water to a neutral pH.
The shop my son works for uses this process regularly to solve cooling problems in older cars and trucks that have been run with our local well water, (rich in lime and Iron eating bacteria). Once cleaned and flushed, the cooling system is filled with the correct mix of coolant, and buffered to the correct pH.
Not saying this is the best solution for everyone, but it works well for me.
I quit buying CLR about 20 years ago when they changed the formula for the Fed's anti-phosphate regulations. It never worked as good as the original even for its intended purpose. Plain ole paint prep from Home Depot works better and less aggressive on brass than vinegar.
I don't use anything. Never worried about it. Never had a problem. Is it possible we're overthinking this?