I have just gone through my coolant system. New radiator core, rebuilt water pump, flushed block, etc. would like some advise on what to run as coolant. Read posts on the web that it is not adviseable to use antifreeze. My radiator guy didn’t think it was a problem. 1928 Star, 4 cylinder.
Definitely use a 50/50 antifreeze mix. Napa sells their own version. Water by itself can result in a microscopic gap between the block and the water. This impedes the heat transfer. The antifreeze insures that the coolant touches the block. "Water Wetter" does the same thing.
Antifreeze is good because of the anti rust and cooling properties, but be sure to use the correct antifreeze for old cars. All antifreeze today is not the same since there have been major changes in the chemical contents. Almost all antifreeze is ethylene glycol based, but the big difference is the additives. The new "Extended Life" or "Long Life" antifreeze uses Organic Acid Technology (OAT), is usually colored yellow, and is NOT the antifreeze to use in your old car.
The AACA website, quoting from an Auburn-Cord-Duesenberg Club publication, states:
"The "Extended Life" or OAT technology works well in late model cars, and should always be used in modern vehicles. However, for our older cars, it can cause serious and even expensive problems. Under NO CIRCUMSTANCES should "Extended Life" antifreeze, which utilizes Organic Acid Technology (OAT, H-OAT, or N-OAT) as one of its chemicals, ever be used in our cars over 10 years old. It attacks the gaskets and gasket cements in our cars, causing major leaks and forcing ultra-expensive repairs. The "Silver Ghost Association" Rolls Royce people have documented massive cooling system failures apparently caused by this anti-freeze product."
The correct antifreeze to use in our old cars is the old dependable green antifreeze we are all familiar with that does not have the new OAT additives. The green antifreeze is officially called IAT or Inorganic Acid Technology antifreeze. It is still available, but you may have to look for it. Some brands are Peak, Peak HD Sierra and Zerex Original.
A lot of info to say use the good green antifreeze in our old cars, not the new yellow Extended Life antifreeze.
This is my experience so far using Evan"s waterless coolant in another collector car. Cast iron block, aluminum radiator, silicone hoses ( a modified classic morris mini pickup). Stuff was not cheap (about $52.00/gal), although the mini only uses a couple gallons. They want you to ideally have NO water in your cooling system(but you can have 3%). I was dealing with a freshly rebuilt motor, new radiator, hoses and heater core, so no problem there. It seemed to work like penetrating oil in finding any small leak, but again I was dealing with a fresh rebuild, so I might of had those leaks anyway. It runs a little hotter (10 degrees F maybe). Now for the good--No water therefore no pressure buildup from steam. You could run a system like our cars have and not have to worry about boiling over (stuff boils at 325 degrees F--if you're there you already have problems). Never needs changing, will not promote rusting (great for our cars that might sit a long time between uses). So far I'm pleased but it is kind of a pain to get going (prep and $) Ross