non-aqueous propylene glycol (NPA) a viable mixture?

[lsusaints7]

I was doing some research on engine coolant and came across the some information that compares the specific heat, boiling point, heat of vaporization, surface tension, and vapor pressure of water and non-aqueous propylene glycol (NPA). A 100% mixture of NPA is superior to water at removing heat when used as engine coolant. It seems to me that when you look at this table, that NPA would be superior to water at removing heat in a combustion chamber as well. Here is the link:

http://www.evanscooling.com/html/tech1.htm

Has anyone ever investigated this? It seems like the same properties that make it a better coolant would make it a better injection liquid. Can anybody elaborate? Is there any reason not to run it other than cost?

[hotrod]

Not suitable for use in internal injection. The "advantages" of NPG as an engine coolant are very controversial (many performance people consider it a snake oil solution). It is not as good a coolant as water, will not atomize as well as water or alcohol due to its high viscosity, its high boiling point will nearly eliminate any evaporative cooling.

Its only advantage as an engine coolant is it will not boil at coolant temperatures that would be a serious risk of causing engine detonation in a high performance engine.

propylene glycol
Specific heat .590 cal/gm (59% of water)
Latent heat of evaporation 168.6 cal/gm (31% of water)
boiling point 187.3 deg C
viscosity 0.581 poise (almost 58 times thicker than water)


water
specific heat 1 cal/gm
Latent heat of evaporation 540 cal /gm
boiling point 100 deg C.
viscosity 0.01002 poise

Larry

[lsusaints7]

Great reply, completely answered my question. I have been researching NPG, and arrived at the same conclusion about running it as an engine coolant. Thank-you for your informative response about using it as an injection mixture. I will stay away from it.