Engine only warms up to 140

[patrickt]

Originally Posted by mr0077

If the radiator perspires it will dissipate heat better in dry weather and low humidity...otherwise, I'd guess wet weather or high humidity would be better for heat dissipation....

You would guess wrong. Forget evaporative cooling for the moment and think convection (that's air moving over your skin, or a horse's skin, or through the fins of a radiator). Did you know that a good 20% of heat dissipation in a horse is through convection, and not sweating? Yep, another trivia point for those bar room wagers. And to increase the rate of heat dissipation through convection in your horse (or through you, for that matter, or your radiator) is to 1) Increase the air flow, 2) Lower the Temperature, or 3) Lower the Humidity. I can't give you an authoritative reference for radiators, but I can for horses. Equine Clinical Nutrition by Lewis, page 247 discusses cooling by convection and humidity. You can read it on Google books if you like (or just take my word for it).
Here you go: http://books.google.com/books?id=vpu...tion#PPA247,M1



Afterthought -- Let's put John (shelby racer) on the spot, since he's a veterinarian, and see if he knows off the top of his head what percentage of heat dissipation in a horse is through convection. Or if he happened to ever own a car that overheated only on really humid days, like I did....