[z-28-mc]

Hi, I have had my engine rebuilt and ready to put antifreeze in it what type would you recommend ? It is a 69 DZ 302 ...all stock...new 4 core radiator and new heater core...Thanks

[69CamaroRT]

i use the peak brand. the green coolant. i wouldnt use the orange dex-cool stuff. heard to many stories with that antifreeze.

[DjD]

Until you fire it up and make sure it doesn't leak and the cam break in is over and you are ready to start driving the car; just use water... Then you can use a 50/50 mix of just about any brand of "green" anti-freeze available. In extreme climate adjust the mix per the charts on the labels...

Avoid the 10 year 100k mile stuff (GM's Dexcool), it's designed for a true closed system where no air mixes with the anti-freeze and your '69 Z was not designed to be closed it requires about 2" of air at the top of the core when filled...

[z-28-mc]

I was just curious because of the aluminum intake and things....Water is a great idea in case of a leak !!!

[DjD]

I think just about all anti-freeze these days has anti-corrosive additives to protect against electrolysis from dis-similar metals... Just stay around the 50/50 mixture rate and you'll be fine.

[1968 Z28]

Whatever type of antifreeze you use, I would recommend that you use distilled water for your dilution. Just works much better than tap water.

[z-28-mc]

Thanks Guys !!!

[joesauer]

Do you plan to use one of those temperature reducing additives? Heard good and bad stories about them.

[flat tire]

when i bought my radiator from champion they told me not to use distilled, but drinking water that you purchase at walmart

[Vega$69]

I would only use distilled water. In Vegas I run 70% water 30% AF. It will run cooler then 50/50 by a few degrees. At 30% it will not freeze until temps are below 0*F.

Straight distilled water cools the best and the AF is to protect against corrosion and to lubricate. It does not improve cooling.

[stratrex]

I prefer distilled because it doesn't have minerals in it which can result in slug build up. Do not use DI water though as I been told by a chemist friend it can be aggressive on metals.

Dave

[1968 Z28]

A story why I prefer distilled water. I worked for a major communications company and maintained many microwave repeater stations that had diesel emergency alternators. They were inside the building with heaters that kept the temperature above freezing so we didn't use antifreeze. We used an anti rust product mixed with distilled water and we never had any radiator or engine crud problem at all. You could look inside the radiator fill cap and see that the copper inside looked brand new.

So that sold me on never using tap water. As Dave said, tap water has too many minerals and they cause crud build-up.

[DjD]

Originally Posted by Vega$69

I would only use distilled water. In Vegas I run 70% water 30% AF. It will run cooler then 50/50 by a few degrees. At 30% it will not freeze until temps are below 0*F.

Straight distilled water cools the best and the AF is to protect against corrosion and to lubricate. It does not improve cooling.

Water period cools better than anti-freeze, it's only called coolant because it is used in the cars cooling system. 32 degs F is freezing which is also 0 degs C...

[JohnZ]

Originally Posted by joesauer

Do you plan to use one of those temperature reducing additives? Heard good and bad stories about them.

If your cooling system is operating properly, there's no need for any "snake oil" band-aid additives.

[z-28-mc]

I was going to use walmart drinking water ,but I was going to boil it first ....The car will be kept in a heated garage so, is there any need for antifreeze?