Packard Forum Index » Post-War (1946-54)

What kind of coolant do you run in your 51-54 engines, especially 54 359 engines?

I had an old timer tell me years ago he ran only distilled water in the summer heat with no antifreeze.

It depends on where you live and the temperatures expected as to whether or not you need antifreeze for freeze protection. Plain water has better heat transfer than ethylene glycol so if you don't encounter freezing conditions, water is preferred. However distilled water is a poor choice, deionized water would be preferable.

If you require antifreeze, do NOT use the extended cycle (usually red) stuff, it's inhibitor system is primarily aimed at aluminum radiators and blocks - go with the old traditional inorganic corrosion inhibitor package stuff - usually green. I generally find PEAK brand to be readily available.

What about straight tap water?

Unless you live in an area with exceptionally hard water, plain old tap water is fine. If you believe in snake oils, there are some things to think about adding, corrosion inhibitors and water-wetters among them. Do they help? - perhaps. Can they hurt? - probably not.

I use plain tap water in my '50 356. Runs fine, no overheating problems even in 100+ degree weather. My garage never gets below freezing and I don't drive the car in freezing weather (Kansas City is big on salted roads).

The other benefit to commercial antifreeze is the corossion inhibitors that also help to lubricate the water pump. Straight water has none of that, so some type of inhibitor is needed. Cast Iron blocks will rust if you even look at them wrong.

I just don't go with running any engine other than an old farm stationary engine on just water. Living where it gets very cold has probably helped this opinion along, but it seems to me that if you can't get an engine to run in the proper temp range with a 50-50 mix of antifreeze and water you have bigger issues than you are acknowledging.

A rust inhibitor is a must use. I even use it in my modern car which runs 178F at 60 mph on the computer PID. I'll have to think about a test to measure just how much more conductive water is than a 50/50 mix. The main ion in "city" water (OEM approved for use) is chlorine which gases off within 24 hours if left standing. Running water without a rust inhibitor is a bad idea given Packard was authorizing ethylene glycol as early as 1933.

You have to compare a motor block that has been using anti-freeze since new to one that has been in a junkyard. The well maintained block will look like new. As well, a cellular core needs rust protection.

If the car boils with anything besides water, then case closed, however in the absence of rust inhibitor then add water soluble oil. (as per the Packard manual).

Although I haven't sent samples out to a lab to see just how much straight water is degrading those motors.

There are several things to consider here besides the actual need for antifreeze; (1) gradual loss of cooling system efficiency from the build-up of scale on the surfaces, both in radiator tubes and in engine blocks, and (2) corrosion of various metals in the system, copper, solder, aluminum, cast iron and steel.

Scale buildup is the easiest to prevent, just use deionized water or antifreeze solutions made with deionized water (which at least one major brand states on the label). The bad actors here are calcium (limestone) and magnesium in hard waters.

Corrosion is a different story. If you've ever cut open a cast iron hot water boiler that's been in service for 50 or 75 years, you'll probably find very little corrosion of the cast iron because it's fully immersed and the water is seldom if ever changed. The corrosion of cast iron is initiated by dissolved oxygen in it - if a cast iron part is partially immersed in water it will rust much more quickly at the interface with air. There are oxygen scavengers for boiler water, they may or may not be a component of quality antifreezes and cooling system corrosion inhibitors, I've never seen one listed on a label but that doesn't mean it's not there. As far as additives which claim to be water pump lubricants, that's just a load of bunk since the bearings which need lubrication are located behind the seals so there is no way for the additive go get to the bearing unless the seal fails, in which case the pump is a goner anyway. Whether such additives play a significant role in preventing corrosion of cast iron I don't know. The second metal in the cooling system likely to suffer corrosive attack is the solder in the radiator and heater core construction. The old style (green) antifreezes have a component to protect solder from corrosion; I'm told the newer permanent (generally red) antifreezes do not as they are intended for aluminum and plastic radiator construction. The old (green) antifreezes were called "permanent" but that meant permanent only in reference to the prior methanol antifreezes which did evaporate. They are still permanent with regard to the freeze protection, but the additives have a finite life so it should be changed every 2 or 3 years for a collector car.

I live in a climate where antifreeze protection is required and my personal preference is to use a 50/50 mixture of traditional (green) ethylene glycol antifreeze, leave it in year-round, and change it every other year. Both my cars still have their original radiators and they have not been rodded or repaired, just flushed from time to time with a water/air flushing gun. Neither car overheats except in very stressful conditions where the temp may rise above normal, but they have never boiled over. That said, if you live where antifreeze isn't required, I don't see any problems with using deionized water (or softened water) alone but if they make you feel better, by all means give one of the proprietary corrosion inhibitors a try.

The third metal in our cooling systems, copper and perhaps some brass, are pretty much immune to attack by anything likely to be found in a cooling system.

Here is one steam boiler rust inhibitor ASTM testing claims:

____ when blended with the proper medium, provides protection which has been tested to the following ASTM Methods:

?D3306 - Light Duty Glycol Engine Coolant
?D6210 - Heavy Duty Glycol Engine Coolant
?D7714 - Light Duty Glycerin Engine Coolant
?D7715 - Heavy Duty Glycerin Engine Coolant
?D7517 - Heavy Duty PDO Engine Coolant
?D7518 - Light Duty PDO Engine Coolant

The standards listed above include the following ASTM Methods:

?D4340 Corrosion in Glassware ◦Copper
◦Solder
◦Brass
◦Steel
◦Cast Iron
◦Cast Aluminum

?D2809 Water Pump Cavitation 100 hrs
?D2570 Simulated Service ◦Copper
◦Solder
◦Brass
◦Steel
◦Cast Iron
◦Cast Aluminum

?D1122 Relative Density
?D1177 Freeze Point
?D1120 Boiling Point
?D1182 Effect on Auto Finish
?D1119 Ash Content
?D1287 ph @ 50% in water
?D3634 Chloride
?D1123 Water wt%
?D1121 Reserve Alkalinity
?D1881 Foaming

While technically you can test any substance to these standards, they are just that - standards. It doesn't mean they passed, only that they were tested. However, this product claims to have met the ASTM standards.

Can you use this product in a car? Of course you can.

These laboratory standards are one of the positive aspects of government spending. Now if they could only get rid of all the crooks.