66 327/350 What is Normal Operating Temp

[William F.]

Re: 66 327/350 What is Normal Operating Temp

Valvolinne makes a racing coolant additive called "racing super coolant" that is compatible with G05(and maybe other types antifreeze,I don't know) although it has anticorrosion protection and the best heat transfer(but no freeze protection) when mixed 10% racing coolant and 90% distilled water, no antifreeze.. Navy Seals use it in their motors. I talked to the engineer who said that "wetter water" is not desirable since it foams, leaving hot air pockets in parts of coolant passages.It seems to help my '67 in hot Southern summers.

[Duke W.]

Re: 66 327/350 What is Normal Operating Temp

Roger-----

I don't know of anything that's better than plain water as far as heat transfer and cooling ability. There may be some "exotic substances" that would work better, but they'd probably be highly impractical. In fact, even ethylene glycol only works well for cooling when it's mixed with water. If you use 100% ethylene glycol coolant you'll find it works VERY poorly for cooling. 70% is about the highest concentration you can use. Cooling will suffer at this concentration, though.

Alcohol was used as an early type of antifreeze. It was not used straight, though; it was mixed with water just like today's ethylene glycol coolants. It is totally obsolete and, as far as I know, not used anymore.

Comparing straight water with Water Wetter and a 50/50 blend of modern commercial ethylene glycol and water is apples and oranges when the suggestion was to add Water Wetter to the latter, and John's report of Viper tests supports what has been previously stated.

Water wetter is designed to supplement water only and is worthless and possibly even harmful if mixed with a properly formulated road engine coolant.

Water has higher heat capacity than glycol and can, with a surfactant reduce temperatures. But this is race car stuff. GM cooling systems at least back to the seventies are designed to have enough capacity to effectively use a 50/50 glycol/water mix. I think when ethylene glycol became standard plant fill in the early sixties the blend was 30-40 percent - maybe more in the winter and for Canadian deliveries.

You'll be replacing a lot of radiators and other cooling system components on a vintage car you intend to last a long time if you decide to run straight water with only a surfactant like Water Wetter. If you use a correctly formulated modern ethylene glycol product with distilled water there is no need for any supplemental additives, and, with reasonable change intervals, cooling system components in good condition will remain so for decades.

Back in the early aircraft engine days beginning at least with the WW I vintage Liberty engine, designers were so worried about aluminum corrosion that they specified straight ethylene glycol as a coolant. That was before effective corrosion inhibitors were developed, and any water in the glycol increased corrosion.

This continued up to WW II, but as power output was increased, straight glycol could not provide sufficient cooling without complete redesigns, so about 30 percent water was added, and they just accepted a higher rate of corrosion.

It was in the early post war years that corrosion inhibitors began to be introduced, and they have become longer lived and more effective as the years have passed, which is why today, we can get away with less frequent coolant changes and still have our cooling system components, like aluminum radiators, last for decades.

Duke