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MrJCRod
11-04-2009, 06:07 PM
http://xjtalk.com/images/special/Photo_110409_011.jpg

Had some free time yesterday so I was able to install some vents in my hood to help drop the underhood temps a little... Let me know what you guys think...

To start here are pictures of the materials I purchased for the vent. Grill-O-Sheets for the mesh

http://i563.photobucket.com/albums/ss72/fsh247/Hood%20Vent%20Write%20up/Photo_110709_010.jpg

and door edge molding from any local autopart store.

http://i563.photobucket.com/albums/ss72/fsh247/Hood%20Vent%20Write%20up/Photo_110709_011.jpg

In this picture it will show the cut-out locations... I did try to make the center line and the top line run parallel to the center line and in the upper edge of the hood as well...

http://i563.photobucket.com/albums/ss72/fsh247/Hood%20Vent%20Write%20up/Hoodvent.jpg

After I laid out my masking tape I measured and drew out my two triangles... then I measured 1 1/2 from the top outer points and drew a line down and measured 3" up from the bottom points and drew a straight line out... I basically just cut the points off...
http://i563.photobucket.com/albums/ss72/fsh247/Hood%20Vent%20Write%20up/Photo_110309_002.jpg then I took my Roto-zip with metal cut-off wheel attachment and went to work cutting out the shapes...
http://i563.photobucket.com/albums/ss72/fsh247/Hood%20Vent%20Write%20up/Photo_110309_003.jpg
http://i563.photobucket.com/albums/ss72/fsh247/Hood%20Vent%20Write%20up/Photo_110309_004.jpg
after grinding down the edges and priming the bare metal I put the door edge molding on... then from under the hood I put the mesh material up against the hood and cut it down a little... After scuffing, priming and painting the mesh I secured them to the hood with black silicone and masking tape to hold them up overnight.
http://i563.photobucket.com/albums/ss72/fsh247/Hood%20Vent%20Write%20up/Photo_110709_003.jpg
The next morning I pulled off the tape and there was my finished homemade hood vents...
http://i563.photobucket.com/albums/ss72/fsh247/Hood%20Vent%20Write%20up/Photo_110409_011.jpg
http://i563.photobucket.com/albums/ss72/fsh247/Hood%20Vent%20Write%20up/Photo_110409_004.jpg
http://i563.photobucket.com/albums/ss72/fsh247/Hood%20Vent%20Write%20up/Photo_110409_002.jpg
http://i563.photobucket.com/albums/ss72/fsh247/Hood%20Vent%20Write%20up/Photo_110309_009.jpg

it was pretty easy, just a little scary making the first cut but overall it can be done in just a few hours... Obviously you can also come up with your own shapes and designs... and if it concerns you, drip pans should be a piece of cake to make if you got this far... Hope this helps.

I'll be hitting all my electrical connections with di-electric to prevent any problems with rain but if that doesn't work I'll add some drip pans under each side... We'll see what happens after a couple of trips in the rain...

KennyB
11-09-2009, 05:46 PM
Now those are very cool... And look easy to do.... Pat yourself on the back...Now long as the rain don't get ya, ya otta be good to go

N1TZU
11-10-2009, 04:26 PM
Awesome job on your fabrication there Mr JCRod....I think the vents done that way look like it was factory made........Cool.....

bassackwards
11-11-2009, 06:23 AM
looks good man

XJcoupe
11-12-2009, 07:22 AM
nice write-up, very cool :thumbsup:

jeepperu
11-12-2009, 08:33 PM
Cheap and very good looking :patriot:

THX for sharing!

JcrOffroad
11-16-2009, 12:34 PM
Those are sweet. Good job!

plobezuki
11-16-2009, 10:27 PM
Nice, very nice!:thumbsup:

Silly Willy
12-10-2009, 10:25 AM
I may be doing that to mine in the near future. I really like it.
Let me know how it does at lowering the temp.

flippedXJ
01-17-2010, 01:12 AM
so its been a couple months have you noticed a big change in temp?

they look good btw - also you could have used jbweld or something like that to hold them on too.

MrJCRod
01-17-2010, 10:22 AM
The vents combined with the electric fan bypass drops temps quite a bit and since I've done it I haven't had any cyl 3 misfires or rough idles on start up from heat soak... I usually leave the fan on in town when I'm running errands and turn it off (let the computer control it) on longer hwy runs... No problems with rain so I never did drip pans and I probably won't...

And as far a JB weld goes, that was an option but since the black rtv is good to 450 degrees and a lot easier to take off if needed I went that route... They're still up there and not coming loose at all...

flippedXJ
01-17-2010, 10:57 AM
good deal I was wonderin how that turned out for ya - since im buildin mine for trails only I may make some since I wont be going fast enough for good air flow.

thanx for the how to

Pops98xj
01-21-2010, 05:21 PM
How are these in the rain?

xjoverkill
02-02-2010, 07:32 PM
They look great. I like how it looks factory.

novastique
03-13-2010, 12:02 PM
Looks great! Any issues with rain or water yet?

MrJCRod
03-14-2010, 06:18 AM
So far all is still good. Stays out all the time, rain or snow. Not one problem.

XJ4IV
03-20-2010, 07:34 PM
I did similar hood vents however I used some vents off a peterbilt truck and used that template and mine stick up above the hood line a little bit BUT I like the door trim idea and I wanted to do this and I actually purchased some but the heat from the motor kept cooking the adhesive and it would peel at the corners... how did you combat that issue?

MrJCRod
03-24-2010, 05:02 AM
I did similar hood vents however I used some vents off a peterbilt truck and used that template and mine stick up above the hood line a little bit BUT I like the door trim idea and I wanted to do this and I actually purchased some but the heat from the motor kept cooking the adhesive and it would peel at the corners... how did you combat that issue?

The door trim pinches the hood, it's not an adhesive. No problems as of yet. The only adhesive I used was for the barbecue grill, and for that the rtv silicone is good up to 450 degrees...

cklanish88mj
06-13-2010, 07:02 PM
great looking

ironmanandy
06-25-2010, 12:24 AM
Talk about simple and clean. Good job man that looks excellent!!!
I've seen so many other guys with 4 times the amount of time in hood vents end up with half the end product!!!

Punisher
07-01-2010, 06:21 PM
I tell ya what, It looks SHARP!!! I LOVE THE LOOK!!!
But I have to ask did it really help lower the heat?
and but how much?
I was thinking of doing the same thing but I would like to put a cowl induction on to keep the water out "yeah I know its a jeep and it can hadle water" but you never know
better safe than sorry...

AtcoOverHaul88
07-13-2010, 01:42 PM
where did you buy the grill o sheets

CT99XJ
07-13-2010, 03:08 PM
Love these vents. By far one of the nicest- and most factory-looking hood vent modifications I've seen.

Baloozabub
09-06-2010, 03:47 PM
Looks great. I saw someone found an old Lebaron at a junkyard and took the louvers from it and put them on their XJ hood and looked real good too.
You can get the grill sheets from Lowe's or any similar type store.
I think the Lebaron louvers from the junkyard cost the guy about $5 for the pair

http://img541.imageshack.us/img541/4096/38768583.jpg

rugidone
09-06-2010, 06:06 PM
I did this in the spring, great mod, havent really had any issues with water with mine, a little smaller than the OP.

It really is amazing to see the amount of heat exiting the vents that I hadn't seen before, so there has to be a difference, I don't think I have overheated since I put them in.

GREAT MOD!

bluedragon436
10-16-2010, 02:31 PM
I like the look of these vents over the Lebaron ones that most go with... have to say they don't look stock, but they def. fit the look much better than the alternatives... Will have to be looking into this for mine when I get home... as I continue to fight the XJ underhood heat!!!

lildigger
07-31-2011, 06:12 PM
hey real neat looks real pro ?how did u wire ur fan switch

willtodo
06-15-2012, 09:42 PM
whats the run down on how u bypassd the comp cont switch,,,did u just tie in witha hot from toggle,,

Rayburne
01-06-2013, 07:39 PM
Cool look for a great price. If anyone worries about them falling off the could use some counter sunk Allen bolts at each corner. I haven't don't this to my XJ yet but have don't this on quite a few pieces of heavy equipment I've worked on that had heat problems or MHSA needed a panel to cover moving parts but still needed to breath. Nice job

92warwagon
02-14-2013, 12:19 AM
any water issues it rains up here in the north west , for us up here we should really cover those up with something?

4.3LXJ
02-14-2013, 09:25 AM
Really, the best thing to do is move them to just behind the radiator. That is the place that does the most cooling and takes advantage of a natural vacuum when the vehicle is in motion.

prcjeep
02-14-2013, 11:15 AM
Really, the best thing to do is move them to just behind the radiator. That is the place that does the most cooling and takes advantage of a natural vacuum when the vehicle is in motion.

I was thinking that would be better... I like the idea you have done with the fans pulling the air out of the rear of the hood... I want to do that but would prefer to have the fans inside/not visible with a grilled like the above in theis thread. Is there enough room for such and to do so inside the engine bay? Do you think it would be as efficient?

Carves
02-14-2013, 04:39 PM
Whilst the OP's pic show a neat job with a clean finish .. :thumbsup:

... and will provide an extra outlet for the fans to shove hot air out ... at low speeds only..


I'm with 4.3LXJ in regards to, constant, effective, vent locations.


Best, "vent" locations are in the dark blue and light blue coloured areas.


http://i1143.photobucket.com/albums/n629/carves-oz/Vehicle%20Bits/Cooling%20Bits/JaguarExahighres15cropped.jpg

4.3LXJ
02-15-2013, 01:24 PM
I was thinking that would be better... I like the idea you have done with the fans pulling the air out of the rear of the hood... I want to do that but would prefer to have the fans inside/not visible with a grilled like the above in theis thread. Is there enough room for such and to do so inside the engine bay? Do you think it would be as efficient?

Yes, you probably could. But those fans are great attention getters :rolleyes:

XjJeepacorn
04-23-2014, 05:49 PM
The best is in the blue? What about a Cowell hood? Something I'm going to work on in the future

MrJCRod
04-24-2014, 03:23 AM
Whilst the OP's pic show a neat job with a clean finish .. :thumbsup:

... and will provide an extra outlet for the fans to shove hot air out ... at low speeds only..



This thread is really old but granted the blue area is best for higher speeds but 1: the location I chose looked good and 2: high speeds aren't where the heat issue was. The Jeep would cool sufficiently when moving, they suffered at stops & on slow trails where airflow was at a minimum. Then heat soak would set in and restarting after 5 or 10 minutes would cause a cylinder 3 misfire.
Higher speed venting was not a factor in determining the location for me. It's not a sport vehicle, it's built for trails. Also, I wired my fan to a toggle with a separate relay so I could have it do 3 things. 1: work normally (on and off with temp or a/c. 2: come on with switch (stay in constantly) and 3: stay off (for deep puddle running), didn't want them to come in when submerged.
Great watching the heat rise out the vents at stop lights.
And for the record , I no longer have the Jeep. Got rid of it a few years ago. It popped back up in my neighborhood about 6 months ago so somebody is still running it but not me. I moved on to other hobbies.

Carves
04-24-2014, 09:00 AM
The best is in the blue? What about a Cowell hood? Something I'm going to work on in the future


Blue is best ..

A proper cowl hood is an induction device ... ie ... its meant to force air into an air box ... just like a snorkle.

There's more to a proper cowl hood than just the visible lump on the outside ... there's also ducting on the under side - to prevent air just wafting all over the engine bay and upsetting the ... in the front/out the back airflow.

Google TruckMasterDesigns for images of their "functional" cowl hoods ... and there's good reading at www.camaro-untoldsecrets.com/articles/article_fs.htm about how, proper, cowl hoods are supposed to work.

Nowwwww .... can you use half a cowl hood ... such as the, no longer made, reflexxions one, or a plastic/fibreglass, bolt on / stick on scoop .... to "vent" the engine bay ??,

Yes, yes you can ... Right up until the forward motion of the vehicle is fast enough, to prevent airflow getting out .... or forces air in - as the speeds get higher.

So for slow speeds only ... half a cowl hood is quite effective as a vent.

... but at highway speeds it can be a liability, causing excessive back pressure in the engine bay and restricting airflow through the radiator, amongst other things.


Something like the flat vents most fit ... and the neat job the OP did .... are probably better than a cowl hood ... as there is less chance of induction at the higher speeds.

Mounting the flat ones closer to the rear corners will also make them more functional, as vents, at the higher speeds,
....... but one has to balance internet mythology, ease of chopping the hood skin ... and personal aesthetics choices ... when choosing a spot to jam the jigsaw in .. ;);)

TMD used to do an XJ hood so I'm led to believe .... apparently it was a bit of an ugly thing due to lumpy vents on the outside edges .... but again ... its a form or function choice.

4.3LXJ
04-24-2014, 09:24 AM
I mounted mine in the blue area and they work very well

ArmyGuy45
04-24-2014, 10:43 AM
I mounted mine in the blue area and they work very well

Do you have any before and after temperature readings?

4.3LXJ
04-24-2014, 01:04 PM
Do you have any before and after temperature readings?

Before, overheating badly when going up hill. After, no overheating anytime

XjJeepacorn
04-24-2014, 01:11 PM
Good to know :) I don't have my eletric fan in right now suppose I should put it back before it gets hot out

XjJeepacorn
04-24-2014, 01:19 PM
Good to know! Hey those fans you have on your hood did you get them out of another car or something?

4.3LXJ
04-24-2014, 05:10 PM
Good to know! Hey those fans you have on your hood did you get them out of another car or something?

The fans are B&M oil coolers for the engine oil and tranny

XjJeepacorn
04-24-2014, 06:34 PM
Neat! I think you told me all about them before