Hi there,

I am almost finish with the engine build. I need to fill the coolant system but I like to have a clean coolant and not the rust crap.

My heads are AFR aluminum and the radiator is also from aluminum.
I have installed a sacrificing anode from zinc at the radiator drain.

This will take care of the electrolysis problem due to the aluminum and cast iron tension differential, but I don't think that it will help to get rid of the corrosion of the cast iron engine block.

I have read that there is some "Dope" that you can add to the coolant to prevent the engine block to introduce rust in the coolant system.

Because I live here at The Netherlands I like to know what is the composition of the dope or say what kind of ingredients I will need to eliminate the rust of the engine.

The engine block is new and never has see a drip of coolant, so this is the time!

Any advise is welcome.
Regards,
Cobra289

 

The anti-corrosive additives are already in the antifreeze.
The rust "problem" is when people leave the same coolant in the system for 10-15 years and the additives wear out. Most current engine systems have both aluminum and iron parts like yours. If you want to leave the coolant in for years use "Dexcool" antifreeze. Regular name brand antifreeze will work fine if it's changed every 3 years in a daily driver.
The only reason to add "dope" is if this car is being raced and the rules require straight water in the cooling system.
If you're worried about rust "dust" from the new engine block, flush the system with water before filling it with coolant.
When mixing antifreeze with water, any drinkable water will be fine. If your area has "hard" water, buy 2 gallons of distilled water. It's like 80¢ per gallon here. The anode is overkill but I'd leave it in.

 

Thanks Supervisor42!

I don't think that I will let the coolant in the engine for 10 years maximum would be 4 years.
You mention Flush the new engine with water (Distilled) what is the reason of that experience? Is it to clean out all the possible debris of the iron cast left there after the sand removal?

I can drive the first 500 miles just with distilled water and than change for the normal coolant, would be that a good choice? Probably you mean just flushing without having any heat cycles.
Please let me know, I will follow your advice.

I have found here a company that deliver several coolants, one that meet the GM 1940650 quality and it is Silicat free it has a fluorescent Orange color. It is mentioned as a long life coolant, so probably will have a good rust inhibitor.
The other meet the VAG-groep (VW/Audi/Porsche/Seat/Skoda) that has the color Green/Blue.

Thanks for your input!
Regards,
Cobra289

 

I wouldn't try to get by with straight water during break-in of a new engine. It needs to have coolant in it when it is run under load.
I meant during the first run up to operating temp have tap water in it to get the "dust" out while setting the timing, checking for leaks, etc. Then drain it and put in coolant.
The orange coolant is probably the equivelant of Dexcool. When the coolant is put in is when to use distilled water to mix with it unless it is "pre-diluted", in which case just fill 'er up.

 

Right, that is clear.
Water --> no load, after that, drain engine and radiator.
Brake-in ---> Coolant.

The orange stuff that I mention is all ready pre-diluted and good for -40C = -40F
Soon the engine will be fired-up after a long re-build of the Cobra where is sitting waiting for the day.

Many thanks.

Regards,
Cobra289