i have about 1ft long 5" wide louvers going on both sides of that center dip of the hood, a few inches bellow the cowl and have never had any problems, with no sheild on my cai ( building one soon) dropped my temp ALOT though but never anything bad has come from it yet, i get abit of rain, no snow yet however maybe soon, i cut my hood to rivet the louvers in from underneath, you can take what you cut out and just use them for covers when you park it, just a thought

edit: your about to get a ft of snow? i hope your not worring about over heating and thats the reason for the vents

almost forgot before going the louver route i was going to get a house hood vent from lowes/ home depot, looks pretty good, cheap, and i could see it working

http://m.homedepot.com/p/Broan-Roof-...K1A/100344509/

id cut a hole in the hood and bring it in from underneath look similar to a poor mans mustang mach 1 shaker hood

edit#2: lol
to clean up the cut hood and if is alil wavey like mine measure the outer diameter of the cut go get small vacum line from a local parts store slit one side so you can slide it on the cut part of the hood ,may need super glue to help hold but looks great

 

How would it not do anything for cooling? You place a hole in your hood and it will allow air to vent. If you have it sealed to a airfilter setup I could see it not cool the engine bay, but that's because the engine would be a source of vacuum and pull air in. If you don't have vacuum it will simply allow air out.

Love the idea and would like to see it in action on a jeep. I just cut holes in my hood last month for some louvers. Dropped temps and made my jeep faster. Lol

 

It only sucks in cold air when it's attached to a carburetor or intake.

Left completely open, the airflow from the front grill will be able to escape through the hood vent.

 

With the low pressure spot at the cowl when your moving a hole there won't do much for cooling it has no vacuum to suck the heat out.Heat will rise but with out the vacuum to pull it out it will just trickle out not really worth cutting the hole to me.Why not build a air box around the radiator to the grill?Its used a lot in racing and does work to funnel the air right in the radiator.

 

Adding hood vents saved my 4.0s life... It dropped my engine temps 12-15 degrees on the hot/sticky summer trails that we have in the south. I would recommend hood vents to anyone with a problem with running hot... Made a world of difference for me!

 

The hole isn't at the cowl it's right above where the hottest part of the engine is. And you're right there's no vacuum but the air moving through the grill being pulled by the fan will help the heat rise out. A lot of people do this for wheeling because there is little to no moving air to take the heat away. As far as building an air box, running the intake to the cowl or out to a snorkel is just as good, also easier as there is less stuff in the way.

I work at a high school and every single locker has louvers on them, I've been trying to find a few for scrap so I can get some badass vents fo free!

Look at the results, I bet you 9 out of 10 people will show you a significant drop in overall temp after adding vents.

 

yup the vents cooled off my running temps alot!!!!!! best bang for your buck in cooling upgrades, also i put sleeves over my injectors and a upgraded efan on a toggle switch over the stock efan and i did all that at once so not sure how much just the vents helped

 

The air is coming into the engine back through the grill and if there's a hole in the hood, it will escape through it, carrying some residual heat with it.