Cooling benefits for flush mount vs shaped hood vents?

[Chezee350]

Hello,

i would like to decrease in-engine bay temperatures during vehicle operation by creating vents in the hood.
however, is it beneficial @ vehicle speed to just have a few holes cut into the hood, or do i need to add louvers or ducting?


can anyone describe the benefits/downside of adding a flush mounted exit on a car's hood versus making a reverse louver in a hood?

i would like just to cut a series of holes and add a mesh to prevent larger foreign objects from falling in, but i'm worried about adverse drag effects and if it will really suck air out of the engine at speed due to the air flow over the hood?

any help would be great.

an example of this type of hood venting idea would be like this:

 

[NickE]

1) CFD is the best way to evaluate performace at different airspeeds.

2) If you cant CFD it, test it in the rain on the freeway, I can see the reversion (i think thats what its called) on the back side of my hoodscoop at speed.

3) properly designed louvers are beautiful.

4) Have fun, often times in this type of engineering if if looks right it likely is.

(Wait for some aerodynamic engineers to come by they might be better.)