Good or bad for cooling?

[T-FATTY]

I've been enjoying my car since it's finally on the road as of this spring. My question is I've been running the car with the hood unlatched so it sits about an inch open at the back.
Is this a release for hot air or is it creating a intake at the back (like a cowl induction hood) and fighting my electric fans?

[dadhad1]

Hey Todd.

I would think it would help cooling. Hot air rises so any release like your open hood would naturally draft upward. As hot air escapes out the top it would be replaced by ambiant cooler air from the outside. Whereas a well sealed hood would hold heat in.

Mike

[T-FATTY]

That's what I was thinking and hoping.

[hammerdown7]

I'm going to give two answers. With the car sitting still or traveling slowly it should help cooling. I'm going to guess that at about 30mph and higher it will run hotter. Air passing under the car moves slower than the air going around and over, which creates a negative air pressure under the car. The addition of the rubber or hard plastic extender under the front valance helps create an even greater negative pressure under the car. This negative pressure actually sucks more air through the radiator. The majority of engine cooling is done by how much air goes through the radiator. Leaving the hood open on a moving car lessens the negative pressure and therefore reduces the amount of air going through the radiator. Also the air going over the hood dams up at the base of the windshield creating a positive pressure which is why the interior vented air uses the openings in front of the windshield to enter the cabin.

Dick

[chevyart]

very nicely explained Dick. i just learned alot from that post art