Topic: Hood louvers

[jfrabat]

So, I was surfing the web, and I came accross these hood louvers. 



Supposedly, adding louvers to the hood can reduce the heat in the engine compartment by as much as 40* (note that this is engine compartment temp, not actual engine temp!), which is a good thing because there will be less damage to plastic parts due to heat, and also because the air coming into the engine will be colder.  And of course, there is the looks issue, which I think they look pretty cool (some of you may disagree, but personally I like them).

So now I am thinking about adding a set to my Jeep, since once I take it down to Panama, 90* days are the average there, and high temps rule year round.

But I am worried about 2 things, and would like your opinion on the subject:

1. Could rain fall coming in through the louvers once the Jeep is parked be a reason for concearn?  I dont think so, because so much water splashes UP from the tires when it rains that it gets wet in there anyway, but just in case...  (by the way, I would obviously install it away from the battery and fuse box, but it would probably be right over the ARB compressor if I install it on the outside of the hood, or the alternator if I go inside)

2. when crossing rivers, the "bubble" effect would be less, so more water would come through the radiator and in to the engine compartment; again, is this something I should be concearned with?

Your thoughts are appreciated!

Felipe

[Mozman68]

I don't think you should be concerned with any of those things...like you said, the bottom and most of the side is already open or partially open.  No bubble effect in my book.

[Jeffy]

Are you having heating issues?  I've had my Jeep in 90% humidity with temps in the 90's as well as humidity in the low teens and the temp over 100 and have no issues.  

[jfrabat]

Are you having heating issues?  I've had my Jeep in 90% humidity with temps in the 90's as well as humidity in the low teens and the temp over 100 and have no issues.  

Engine temp is fine; but the engine compartment is getting a bit too hot.  Plus, I like the look of the louvers...  Yeah, I know...  Stupid reason to ad them, but I like the look.

[Mozman68]

Laurie's one smart cookie...and drive's her Jeep in Oman...check her site out.


http://www.oman4x4.com/hoodvents.htm

[Jeffy]

Engine temp is fine; but the engine compartment is getting a bit too hot.  Plus, I like the look of the louvers...  Yeah, I know...  Stupid reason to ad them, but I like the look.

So, really this is about looks then anything else. 

[95yjman]

Hey you gotta look cool to get the chicks man

[neale_rs]

Laurie's one smart cookie...and drive's her Jeep in Oman...check her site out.


http://www.oman4x4.com/hoodvents.htm

Pretty impressive testing!

[jfrabat]

So, really this is about looks then anything else. 

So, really this is about looks then anything else. 

Hey you gotta look cool to get the chicks man

You got it!

Laurie's one smart cookie...and drive's her Jeep in Oman...check her site out.

http://www.oman4x4.com/hoodvents.htm

That's where I got the original idea from; I found a couple of those Pontiac louvers on eBay, but I figured aluminum should be better than plastic, so I am now looking at the GenRight louvers...

Honestly speaking, there is A LOT of heat in the engine compartmet; if you can really lower that by 40*, theoretically, that would be similar to isntalling a CAI intake (as the air would be colder).  Combine that with the durability of the components as they are now exposed to less heat, and its a win/win situation (looks cool and helps a little!).

[oldjeep]

If you really want it to help you need a place for the air to escape.

These look pretty bad, but would provide a lot more cooling:
http://www.idealoffroad.com/shop/product.asp?p=217


I think this one looks a bit better but a lot more $$
http://www.atozfabrication.com/catalog/19972003jeepwranglertjcyclonelouveredhoodinsert-p-181.html?zenid=b02bc6d67a33762c93c92507a1bdab0a

[jfrabat]

Well, if you look at the site Moz posted, Frank D. did his homework; this is the high temp areas UNDER the hood of a 4.0L TJ:



This is the low pressure areas on TOP of the hood (@25mph):



And this is the overlay of both graphs:



So by using the vents where there is heat below the hood and where the Jeep's aerodynamics pull the air from the engine compartment, you can get a lot of air moved through a relatively small hole.  Granted, when you are wheeling at very slow speed, the air will not circulate as good (although it would still be better than nothing), so the temp drop will not be so dramatic (although still it is good)...

So, based on this, I am thinking about doing only the ones on the sides. 

With the Pontiac louvers, Frank D. got the following drops in temp:

11 degrees F at Idle.
16 degrees F during Stop and Go
27 degrees F during Highway Travel

So it seems it defenetly works...  And you dont need half a million holes (or spend $100 or more) to achieve a drop in temp...  I dont know how much temperature drop on the intake you get with a CAI, but 27 degrees HAS to make a difference!

I AM thinking about getting the louvers lined (along with the CB antena mount, which is starting to rust, and the vent grill already on the hood, which I also got a metal one some years ago and is also starting to rust) to match the bumper finish, but I have not decided on that yet...

[oldjeep]

Just realize that his diagrams are only relevant to a jeep with the same amount of lift and front bumper combo.

[jfrabat]

Just realize that his diagrams are only relevant to a jeep with the same amount of lift and front bumper combo.

I thought about that, but the effect of the bumper is negligeable; the whinch would affect more the airflow through the radiator, which would also affect the airflow inside the engine.  The lift does affect, but from what I could see in the pictures, I would guess he's either running 33" or 35" tires, which would mean he is areoun d what I will have.  What worries me more is the fact that he has the I6 and I have the I4 with the e-fan, which means that there is a big distribution difference inside the engine compartment, which WILL affect airflow, and thus the hot pockets.  But the aerodynamics should be about the same on the outside, so the Jeep should still be pulling a vacuum at about the same spot.  I do plan to use a video camera and some yarn to double check, but I would doubt there will be any differences...

[oldjeep]

He's also got a TJ

[neale_rs]

Some XJ owners put a small electic extractor fan right over the engine.  One local jeeper put one on his YJ after swapping in a V8.  It helped a lot with the cooling, very likely more than louvers.