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Old 28-09-2009, 01:39 PM   #31
EL Ghia 6
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Quote:
Originally Posted by irish2
Glycol is also an anti boil agent. With glycol you can have a hotter motor without it boiling. Some motors simply require glycol as they run hot for fuel atomization. Even with a high pressure cap under hard driving the system can get hot enough to boil in certain cars.
Glycol only raises the boiling point by 9 degreese (Cooling system at 20 PSI using water with no glycol boils at 126C and 50% water/glycol boils at 135C) + it reduces the heat transfer ability of the water + in the case of the EL ford dont recommend anything more than rust inhibitor
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Old 30-09-2009, 08:26 PM   #32
torbirdie
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Waterwetter, never used it, but have seriously looked at and the claims made by redline.

What concerns me most is that it claims to make better heat transfer between the coolant and the cylinder head, remove hot spots from nucleate boiling etc.

Unfortunately this is not in line with their claims nor many of the testimonials for the product. If more heat was being transferred to the coolant at these hotspots, the coolant temperature would increase, but all reports are for lower coolant temperature. One could argue more heat transfer at the radiator due to the wetter, but this is typically where the surfaces not in excess of boiling point where the wetting agent supposedly works.

It would be more relevant if they actually did their tests showing the actual temp of the cylinder head, not the coolant.

In regards to the comments about using glycol mixes versus straight water.
Yes, glycol has a lower thermal conductivity and heat capacity than water. However, these two properties dont stop it being just as an effective coolant as water in an engine. The coolant is being used as a heat transfer medium, not to actually absorb the heat. It is just as effective in transferring heat as water, though some design differences have to be made. A 50/50 mix glycol/water still has 85% of the heat capacity of water, this doesnt mean the car will run hotter, it just means the coolant will need to circulate ~15% faster to achieve the same level of cooling, see:
http://www.engineeringtoolbox.com/et...col-d_146.html

Cars where this is the recommended coolant mix, have been designed with this in mind, the water pump moves more coolant. Users should beware of second guessing the manufacturer here. If the glycol was just for freezing protection the manufacturers wouldnt need to specify 50/50 for our condtions.

For example many say they wont be experiencing freezing conditions so will just use water with some corrosion inhibitor.

With the higher pump speed and lower boiling point of water, there is a risk that at high temps and higher rpm that there will be vaporisation at the low pressure side of the system, cavitation at the water pump, and all the problems that go with that.

Likewise using a heavy glycol mix in an older car may see the water pump not move the coolant fast enough and overheating caused by that.

In regards to race cars using straight water etc, I thought it was more to do with that if there was a coolant expulsion on the track that it would make it slippery, but dont know too much about that.


In regards to using distilled water, its not really necessary if you have a good water supply. Coolant Check your local water suppliers website, the results of their testing is public.

The levels of contaminants in cities such as Melbourne are very low and will be insignificant to the contaminants that are still going to be in the block(no matter how well you clean it) that you are going to add the distilled water to!

Last edited by torbirdie; 30-09-2009 at 08:36 PM.
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Old 30-09-2009, 09:03 PM   #33
irish2
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Quote:
Originally Posted by john rv
Glycol only raises the boiling point by 9 degreese (Cooling system at 20 PSI using water with no glycol boils at 126C and 50% water/glycol boils at 135C) + it reduces the heat transfer ability of the water + in the case of the EL ford dont recommend anything more than rust inhibitor
I never said to run glycol in an EL. I know a couple of mates cars that boil with normal water but run fine with a glycol mix. Both cars are boosted.

In industrial steel or mixed alloy piping systems glycol, not rust inhibitor is used to prevent scale and/or corrosion. The reason is high quality glycol lasts longer without loosing it's inhibitive properties than a simple rust inhibitor.
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