Running straight water

[MrTube]

Ah I see Paul. Thank you for the explanation.

 

[John Stone]

You are absolutely correct. But the difference in specific heat value between water that boils at a lower temperture and the specific heat value of a 50/50 mix that might boil at a higher temperture cancels out any benefit as far as heat tranfer is concerned. In English, even though a 50/50 mix might boil at a higher temperature, an equal volume of straight water absorbs much more heat at a lower temperture than the same volume 50/50 mix can at a higher temperture. Therfore straight water is a superior cooling medium regardless of temperture in non-pressurized systems. No rust protection though. Remember, temperature and heat are two very different things. Overheating is caused by heat, not by temperture. Modern cooling systems run fine way above 212 degrees and cause no overheating problems. Your model A cooling system will overheat and fail at or below 212 degrees. Temperture is not the cause of overheating. Excess heat is! You need a modern, pressurized cooling system to take advantage of the higher boiling point of a 50/50 mix. In a Model A, the engine will overheat faster with a 50/50 mix. It takes less heat to get that mix to its higher boiling point, than it takes to get staight water to its lower boiling point given equal volumes of liquid.

Now that is good information. I have been telling people that for years and never had the scientific explanation. I will have to print this out for the file.

Thanks.

 

[30ccpickup]

Correct me if I am wrong, but a properly tuned/maintained Model ‘A’ (ignition, carburetion, and cooling) will not overheat with pure water or with a 50/50 antifreeze solution (If driven correctly). Pure water will help with overheating, but there is still an on-going problem if you are running too hot. With antifreeze having a rust inhibitor it can be considered as a preference during the summer. I personally prefer water with a rust inhibitor for environmental reasons; I am constantly fixing what ain’t broke and am removing my radiator constantly. I too thank Paul from Maine, and I hope he will allow me to quote him later on my website, when I get to the cooling system, either way it was well said, and in layman terms.

 

[JoeWay]

...When I pulled the head this winter the entire block and head was full of rust. I flushed it with oxalic acid and washing soda,so it is now clean...

John,

Could you describe your flush procedure? Concentration of oxalic, duration of flush, source of acid, and so forth?

Thanks.

Joe