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General Forums => The Mess Hall => Topic started by: jfrabat on October 22, 2008, 11:13:15 AM

Title: Hood louvers
Post by: jfrabat on October 22, 2008, 11:13:15 AM
So, I was surfing the web, and I came accross these  (http://www.polyperformance.com/shop/Jeep-TJ-LJ-YJ-Hood-Louver-Set-p-2374.html) hood louvers. 

(http://www.polyperformance.com/shop/images/P/t_2374.jpg)

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
Title: Re: Hood louvers
Post by: Mozman68 on October 22, 2008, 11:30:52 AM
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.
Title: Re: Hood louvers
Post by: Jeffy on October 22, 2008, 11:31:49 AM
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.  :confused:
Title: Re: Hood louvers
Post by: jfrabat on October 22, 2008, 11:36:24 AM
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.  :confused:

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.
Title: Re: Hood louvers
Post by: Mozman68 on October 22, 2008, 01:33:08 PM
Laurie's one smart cookie...and drive's her Jeep in Oman...check her site out.


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

Title: Re: Hood louvers
Post by: Jeffy on October 22, 2008, 01:51:27 PM
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.  :lol:
Title: Re: Hood louvers
Post by: 95yjman on October 22, 2008, 02:46:47 PM
Hey you gotta look cool to get the chicks man :smokes:
Title: Re: Hood louvers
Post by: neale_rs on October 22, 2008, 02:57:40 PM
Laurie's one smart cookie...and drive's her Jeep in Oman...check her site out.


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



Pretty impressive testing!
Title: Re: Hood louvers
Post by: jfrabat on October 22, 2008, 03:00:10 PM
So, really this is about looks then anything else.  :lol:

So, really this is about looks then anything else.  :lol:
Hey you gotta look cool to get the chicks man :smokes:

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 (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!).
Title: Re: Hood louvers
Post by: oldjeep on October 22, 2008, 05:27:17 PM
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
(http://www.deepvoodoo.net/catalog/gasskid/GenRite/Louver_5pc_3.jpg)

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

Title: Re: Hood louvers
Post by: jfrabat on October 22, 2008, 06:07:15 PM
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:

(http://www.oman4x4.com/frank/hoodtemp.jpg)

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

(http://www.oman4x4.com/frank/hoodpresr.jpg)

And this is the overlay of both graphs:

(http://www.oman4x4.com/frank/hood2.jpg)

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...
Title: Re: Hood louvers
Post by: oldjeep on October 22, 2008, 09:49:02 PM
Just realize that his diagrams are only relevant to a jeep with the same amount of lift and front bumper combo.
Title: Re: Hood louvers
Post by: jfrabat on October 23, 2008, 09:01:48 AM
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...
Title: Re: Hood louvers
Post by: oldjeep on October 23, 2008, 09:03:43 AM
He's also got a TJ ;)
Title: Re: Hood louvers
Post by: neale_rs on October 23, 2008, 09:23:58 AM
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.
Title: Re: Hood louvers
Post by: Jeffy on October 23, 2008, 12:30:53 PM
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.

XJ's especially the earlier ones have marginal cooling from the factory.  It shouldn't really be an issue with a YJ though.  Add some tube fenders and you shouldn't have any worries since there are no inner wheel wells.  :thumb:
Title: Re: Hood louvers
Post by: Oilsmoke on October 23, 2008, 08:13:42 PM
Add a 4 cyclinder and you can cut the Heat  by a 1/3   8)
Title: Re: Hood louvers
Post by: FourbangerYJ on October 27, 2008, 04:06:24 PM
(http://i30.photobucket.com/albums/c331/FourbangerYJ/April3008080.jpg)

(http://i30.photobucket.com/albums/c331/FourbangerYJ/April3008081.jpg)

I went this route. I didn't have a overheating issue.  I was bored and wanted a easy project.
I picked up a 2 X 4 piece of the 1/8 inch holed steel for $7.00. I used some double sided tape to hold it on.
Title: Re: Hood louvers
Post by: Jeffy on October 27, 2008, 04:08:21 PM
Buick Roadmaster or holl drill that hasn't been used since the taillights...  :lol:
Title: Re: Hood louvers
Post by: jfrabat on October 27, 2008, 04:09:46 PM
I went this route. I didn't have a overheating issue.  I was bored and wanted a easy project.
I picked up a 2 X 4 piece of the 1/8 inch holed steel for $7.00. I used some double sided tape to hold it on.

I think that my favirite thing are your stickers!

Fool injected!  4 Squirrels Inside!   :roflol:
Title: Re: Hood louvers
Post by: FourbangerYJ on October 27, 2008, 04:12:29 PM
Buick Roadmaster or holl drill that hasn't been used since the taillights...  :lol:

I get the Buick comment alot! When you stand back a few feet they look like stickers.

I used a jig saw to cut my tail lights :blbl:
Title: Re: Hood louvers
Post by: Jeffy on October 27, 2008, 06:00:20 PM
I get the Buick comment alot! When you stand back a few feet they look like stickers.

I used a jig saw to cut my tail lights :blbl:

3M foam tape?

Those MTR's are really chewed up.

BTW: what rocker guards are those? DIY?
Title: Re: Hood louvers
Post by: FourbangerYJ on October 27, 2008, 06:24:49 PM
It is 3M tape. I got it at Lowes. It's super sticky! I guess it does have a foam center. Maybe 1/16 thick 1 inch wide.

The MT/R's I got used. They were already siped. After running them a few years I grooved them. It's hard to see in that PIC. I sold the tires and wheels when I went to 37's. Which I bought used. I grooved them too. I don't have a PIC yet. I like the way they hook up!

Rockers are some Blem Genright. They are just down the street from me. I did have some homebrew ones on before that though.
Title: Re: Hood louvers
Post by: chardrc on October 27, 2008, 07:20:40 PM
Add some tube fenders and you shouldn't have any worries since there are no inner wheel wells.  :thumb:

mmm muddy water cooling system...
Title: Re: Hood louvers
Post by: Jeffy on October 27, 2008, 07:34:08 PM
mmm muddy water cooling system...

Not like the inner fenders are going to keep the engine that much cleaner.
Title: Re: Hood louvers
Post by: jfrabat on November 13, 2008, 08:26:25 AM
Well, just thought I'd let everyone know I ended up getting the Pontiac louvers (like the ones in the article Moz posted).  I'll get some pictures after I install them...
Title: Re: Hood louvers
Post by: islwayn on January 08, 2009, 01:19:21 PM
my 79CJ with the 401 HiPerf Turbo charged motor used to create a lot of heat..  I took it to a hot rodder friend that had a louver machine.. he punched louvers in the back edge of the hood to let the heat accumulated out.. I had the hood all repainted.. looks much better than those bolt in units..  classier for sure..  I put pans under them for the drain off so the water didn't dump on my engine.. 
Title: Re: Hood louvers
Post by: YJmechanic on January 09, 2009, 11:01:04 PM
i have seen that article before and i like that someone did that good of research before a mod that most would just stick where ever looked the best,  on the other side i don't think with the e fan and a four cylinder you have much to gain in temp drop considered that combo creates a massive hole in the front anyway but i guess as far as heat escape it may help some, but i would just brake them anyway considering i walk across my hood when in deep mud and have to hook up or operate my winch
Title: Re: Hood louvers
Post by: jfrabat on January 10, 2009, 06:27:24 PM
on the other side i don't think with the e fan and a four cylinder you have much to gain in temp drop considered that combo creates a massive hole in the front anyway but i guess as far as heat escape it may help some

I would think it would help quite a bit, as when I open the hood, I can feel the heat coming out.  Also, when the fan kicks in, I can feel the hot air coming out from UNDER the Jeep...  I have yet to install them (same with the Safari Snorkel), though, so I have no idea if they will help or not.
Title: Re: Hood louvers
Post by: dexetr30 on January 11, 2009, 09:00:46 AM
I would think it would help quite a bit, as when I open the hood, I can feel the heat coming out.  Also, when the fan kicks in, I can feel the hot air coming out from UNDER the Jeep...  I have yet to install them (same with the Safari Snorkel), though, so I have no idea if they will help or not.

Post pics when you get them installed. I've been thinking of doing this for some time. Maybe when the temps get a bit warmer (low single digits coming this week) I'll head over to the scrap yard and look for a set myself.
Title: Re: Hood louvers
Post by: YJmechanic on January 11, 2009, 08:57:16 PM
well let us know if it turns out to help or not, i'm sure it will help a little just curious if it helps enough to make it worth the effort
Title: Re: Hood louvers
Post by: jfrabat on April 18, 2009, 05:54:01 PM
well, I FINALLY got around to doing this; I got one in and tomorrow the other will go in.  So far so good.  I like how it looks, although I have done noe heat tests at this time (and I have no pics cause it was nighttime when I finished and I did not have my camera).  I'll post some pics when I'm done...
Title: Re: Hood louvers
Post by: jfrabat on April 19, 2009, 01:19:58 PM
Here are the pictures...

(http://i46.photobucket.com/albums/f138/jfrabat/Jeep/DSC00096.jpg)

(http://i46.photobucket.com/albums/f138/jfrabat/Jeep/DSC00091.jpg)

(http://i46.photobucket.com/albums/f138/jfrabat/Jeep/DSC00089.jpg)

(http://i46.photobucket.com/albums/f138/jfrabat/Jeep/DSC00088.jpg)

(http://i46.photobucket.com/albums/f138/jfrabat/Jeep/DSC00092.jpg)

(http://i46.photobucket.com/albums/f138/jfrabat/Jeep/DSC00098.jpg)

I painted the louvers in Duplicolor's textured black, and I really like how they turned out...  I also painted the plastic cover for the air intake for the heater in the same color so they would match (I had replaced the plastic one with a metal one because the plastic one looked pretty worn out, but the metal one was rusting, so I replaced it with the painted plastic one again).

As for how they work, I have no way of measuring the engine compartment temp, but let me tell you, you can actually see the hot air coming out of the things!

Felipe
Title: Re: Hood louvers
Post by: TN00TJ on April 20, 2009, 05:44:02 PM
Well, you've just inspired me to do mine...

Very nice, indeed.
Title: Re: Hood louvers
Post by: jwalls4x4 on April 21, 2009, 09:16:55 PM
I like what you've done there :thumb:

I think that my favirite thing are your stickers!

Fool injected!  4 Squirrels Inside!   :roflol:

X2
Title: Re: Hood louvers
Post by: chrisfranklin on April 22, 2009, 05:09:39 AM
Those vents look good Felipe.  They're an example of form-following-function compared to the bogus vents/scoops/doo-dads that are on most modern cars/trucks .  Maybe it'll help your underhood intake temperatures too.

If I lived in the desert over here in the west, I'd probably follow on and do a little hood vent surgery myself  :biggrin:  I'd probably go the green body color with the hood vent and 2 new vents, but that's just me.
Title: Re: Hood louvers
Post by: melbill on April 26, 2009, 05:23:38 AM
They look really good. I have been debating adding  louvers to mine and I think I will qfter seeing yours.
Title: Re: Hood louvers
Post by: Mozman68 on April 26, 2009, 08:22:42 AM
Boy...really surprised at how much they look like they were made for the Jeep hood.  Nice work.  :thumbsup:
Title: Re: Hood louvers
Post by: jwalls4x4 on April 28, 2009, 08:24:18 PM
Boy...really surprised at how much they look like they were made for the Jeep hood.  Nice work.  :thumbsup:

X2

Also, I see your hood has the same two 'my hood flew off the prop on a windy day' dents that mine does :'(  I wander how many are in the same boat?
Title: Re: Hood louvers
Post by: jfrabat on April 29, 2009, 07:21:43 AM
Also, I see your hood has the same two 'my hood flew off the prop on a windy day' dents that mine does :'(  I wander how many are in the same boat?

Actually, those are my "my hood popped open when I crossed the railroad tracks doing 40 mph and I almost SH#$ my pants when it happened" marks...
Title: Re: Hood louvers
Post by: Rocko on April 29, 2009, 07:43:17 AM
When ever I go pass on comming semis the hood tries to do that. It's tryin.
Title: Re: Hood louvers
Post by: jwalls4x4 on April 30, 2009, 07:22:04 AM
When ever I go pass on comming semis the hood tries to do that. It's tryin.

X2...Pucker moment every time :eek:
Title: Re: Hood louvers
Post by: turbolove96 on May 21, 2009, 02:46:20 PM
I'm getting ready to add louvers to mine.  I just got back from moab last weekend and in the roasting dessert heat i could have fried breakfast on my hood.  And shortly after i started to see a slight engine temp increase.  So for the rock crawlers its a great idea.  Just as a side note i have tube fenders that I made myself so they dont have inner fender wells and i was still heating up.  It's that whole wierd physics thing that heat rises.   :fish: