Hood vents best location?

[Southern96XJ]

I grabbed some JY hood vents off a Grand Cherokee that looked stock? Any ways they have a bottom plate to make the install look clean. Just wondering where they would have the most benefit? It looks like my options are limited anyways as I do not want to cut through the hood supports. So I am guessing closer to the center, close to the windshield... Please let me know you thoughts or suggestions.. thanks guys!


Here they are:

 

[DeftwillP]

Must have been a 5.9 grand. It was a one year thing back in 98.

Maybe put them in the same place that they were on the grand hood??

 

[Tim_MN]

Install them in the same place Jeep did.
.

 

[RollTider]

http://jeep-xj.info/HowtoBonnetVents.htm

 

[sallys xj]

my vents are here but are much cheaper, they are BBQ grill inserts painted black..yeah im cheap but they work.

 

[sallys xj]

this stuff called "quick steel" is holding them in place, cheap and effective.

 

[ju82takata]

Nice!

 

[sallys xj]

^^ yeah all in all it was maybe 20 bucks in parts, BBQ grill inserts, door trim, and the quick steel. Took a few hours and came out great and it works. my elc. fan pushes air through the engine bay and all the hot air escapes from those vents.. Living in AZ and wheeling when its 110 out gotta do all you can.

 

[ericfx1984]

Install them in the same place Jeep did.
.

when did the XJ come with hood vents factory?

 

[CharlesS]

when did the XJ come with hood vents factory?

Actually the question should be.....
Where did the XJ come with the hood vents from the factory.....??
They were issued on the XJ in Europe as evidenced by the steering wheel on the right side...

 

[vt98xj]

Pretty good discussion on the topic http://www.jeepforum.com/forum/f11/hood-vents-placement-best-ventilation-1127028/index2.html

 

[Milford Cubicle II]

I would only worry about vent location for low speed cooling, I wouldn't worry about high speed. Mainly because on the highway there is going to be much higher air pressure coming through your grill/front pushing air through the engine bay than there will ever be towards the back of your hood.

I know this to be true from the enormous intake air temp difference in my Jeep between low speed/idling and highway speeds according to my scangauge. And I have a rocket intake that goes across the valve cover to the "cool" side of the motor so the temperature difference isn't because of any cold air intake setup I have or anything.

So I'm suggesting asking the question, "What's the best hood vent location for low speed operation?"

 

[austinaubinoe]

Actually the question should be.....
Where did the XJ come with the hood vents from the factory.....??
They were issued on the XJ in Europe as evidenced by the steering wheel on the right side...

The European market got an Orvis XJ in the late 90's. Even though they look just like the 5.9 vents, pretty sure they were non-op. Coolest thing about the Orvix XJ was its rear air deflector that went around its 3rd brake light.

Off topic I know, but this jeep is just awesome!

http://www.naxja.org/forum/showthread.php?t=1051964

 

[Tim_MN]

So I'm suggesting asking the question, "What's the best hood vent location for low speed operation?"

Define "best".

Most people put Le-Baron hood vents in the middle of the hood because that where they fit. I have Pontiac Sunbird Turbo vents in the middle of the hood and they vent tons of hot air air. Answering "wherever they fit" is not a smart azz answer, when it proves to be true. Hot air rises and will find its way out.

.

 

[techno1154]

Both the XJ and WJ with the Orvis package came with hood vents. I have seen plenty of them in the Caribbean.
The placement is dependant on a couple of things.
1) Where they are placed is where the fans forces air onto the hood. This is evident by the oily/dirty residue on the inside of the hood.
2) That area of the hood have a low (negative air) pressure when the vehicle is up to speed causing a vacumn of sort that help to evacuate the hot air immediately behind the radiator.
How effectively are they? Some who have them would be able to let us know.

 

[Milford Cubicle II]

Answering "wherever they fit" is not a smart azz answer, when it proves to be true. Hot air rises and will find its way out.

I agree. And what I mean by "best" is what spot will let the most hot air out at low speeds. For our application, I'm betting that putting a huge vent centered over the driver's half of the hood would be as good as it gets. But that would look dumb.

If you have a temp gun, then temp different areas over the top of your hood when your Jeep is warm and idling. Find the hot spots to get an idea of good vent placement.

Also I've noticed that with dual stock electric fans, you can feel them blowing air all the way to the firewall. You could get a spray bottle full of water and try to squirt it through the radiator to get picked up by the fans and see where it hits the hood.

 

[Kevin108]

Not my info, just something I've seen.
http://www.oman4x4.com/hoodvents.htm

 

[Darky]

That's great for a TJ but XJ aerodynamics are a bit different...

Mine are in middle of the hood near the back. Why? That's where they fit with as little hood support interference as possible. They work, hot air pours out while idling. I put absolutely no thought into high pressure vs low pressure, hood temps etc. I may have touched the hood a couple places, but really I just flipped it over and compared the vents to hood support placement.

 

[jbmoose]

I put mine so that the driver's side was directly above exhaust manifold. Then i just matched up the other side

 

[Kevin108]

That's great for a TJ but XJ aerodynamics are a bit different...

Very much so as we have basically no dead space under the hood. The hot spots are likely the same but there's no reason the process he used couldn't be done by one of us.