"Ron Natalie" wrote in message om...
"Jay" wrote in message om...

I'd put forth the idea that the worst
case environment for an aircraft is always better than the worst case
for an automobile. Does anyone disagree on this point?

Yeah, I do. Many cars typically don't operate at 80% of rated power for long
periods.

Depends on how you define "long period". For the puposes of this
discussion, any amount of time over the amount of time it takes to
heat the water volume and block I would call "long" Thats probably on
the order of a several minutes. Driving up a long grade on a hot day
(which is where I see all the blown radiators) seems like it would
meet the high output for "long" time case.

Therefor, a cooling surface directly exposed to the prop wash does not
have to be as large in area as that of the radiator orginally designed
for that automobile.

Cars have fans too.

I'm not sure its fair to compare a 10" 1/4 HP electric fan to a 150HP
propeller.