I have a cast iron block and head BBC with a BECOOL aluminum rad, I just flushed and re-filled with Prestone long life and distilled water with a 65/35 mix good for -50c and 1 bottle of Water Wetter, The pH is 8.55 My question is what the correct pH to have for this setup, I do not want to harm the rad. The Prestone right out of the jug has a pH of 8.95 so once I add water it drops to 8.55 Two rad shops in town gave different advice, one said 8.55 was OK and the other said a pH of 9.5 to10.5 The guy at Becool said pH did not matter, just mix 50/50 and you will be fine if you replace it every year. What is everyones thoughts on this matter???

I'm with your BeCool guy. Never heard of PH balancing a cooling system.
Here's the problem with mixing aluminum and iron. Electrolysis. It can lead to a rapid failure and blowout of aluminum parts. All it takes is a little flake of iron that entered the radiator and settled to the bottom. I haven't done this (yet) but mixing a batch of epoxy and pouring it to the bottom of each tank will keep any iron at bay. Like those glass lined water heaters. Good for life.

i cant remember the company but we carry their product at work. it serves the same prupose as water wetter but also has a built in ph indicator. when the color disappears from the coolant its time to add more.

The "anti freeze" is made of 2 compenents
1/glycol to stop the water from freezing..nothing else
2/Some buffer chemicals, this stop electrois as mentioned above...

There are several types of 'buffer" and this depends on what part of the world you are in and the nature of the local water supply.

Unless one has a good chemistry background, understands ionisations soduim, phospates and the such, and how this relates to pH etc...hey should not be opening their mouths
Two rad shops in town gave different advice, one said 8.55 was OK and the other said a pH of 9.5 to10.5

On the other hand this advice is right on
The guy at Becool said just mix 50/50 and you will be fine if you replace it every year. note the removal of the pH part.

And lets face it , and engine flush at lesat once per yr is as important as regular oil changes and checking tyre pressures...regardles of milage.

Geeze Steps, I run a closed cooling system and get 10 years out of my antifreeze. No air=no corrosion. You know, like every car made for the last 30 years, at least.

The trouble with "no corrosion" is you dont know unless one pulls the engine down.

One boat outboard motors used in sea water they have a magnisiunm alloy plate bolted on the cavitation plate...this corrodes instead of the motor..
I believe the el cheapo goose nects also happen to be a high Mg alloy...these have a habit of only lasting a few yrs before corrossion causes leaks...which is a very stong case to use the elcheapo 'O' ring goose necks.

Isn't it more of an issue how much voltage drop you are seeing across the radiator inlet and ground (electrolysis)? With 0.3v and under what you want to see past that and you will see a corrosion. I always understood once the volt becomes high enough that is when you want to change your coolant.

PH I would think would be more dependent on coolant type and mix.

What you guys are talking about are zinc anodes, on outboards, and outdrives. Dont forget the anodes at the back windows of the first gen camaros, they were in the lower rear window channel to slow down the rust.

Dont forget the anodes at the back windows of the first gen camaros, they were in the lower rear window channel to slow down the rust.

I did not know that...I cant rem seeing them...got a pic at all?

After more reading I found out that "Long Life" green antifreeze has a starting pH of 8.5, And regular green antifreeze has a pH of 10.5
I mixed mine 60/40 and ended up with a pH of 10.21 So the moral of the story is stay away from "long life" antifreeze, flush and change every couple years and everything will be good.