Hood Vents

[Karlm]

That looks sweet

 

[Gojeep]

I am planning to install my hood vents this Tuesday. I have the LeBaron Turbo vents that seem to be popular to use on XJs. They will be put further back on the hood closer to the windshield. There is a slight slope to the hood and this is the highest part (heat rises).

The biggest reason I want to install the vents is to release heat from the engine compartment which builds up crawling along the trails in the hot summer.

I also bought some plexi-glass and magnetic tape to make a cover that I can slap on for wet weather to prevent water dripping on the engine. But I plan on keeping the back of the covers open to still allow heat to escape.

I plan on doing a write up on my site and will let you guys know how it turns out.

Do not put them near the back as this is a high pressure area on a XJ. It will still work at low 4 wheeling speeds but not at all on the street.

Take a look at any new million dollar world rally car and they all have hood vents in the front section. Ideally you will find them placed directly behind the radiator where the negative pressure above the hood from the air being first compressed at the front of the car is then bounced over the leading edge of the hood. Under this stream is the negative pressure zone where a vent is the most effective like already shown on some photos in this post.

 

[EricsXJ]

Do not put them near the back as this is a high pressure area on a XJ. It will still work at low 4 wheeling speeds but not at all on the street.

I understand your logic, but everyone who has the LeBaron vents put them at the rear because due to the size thats about the only place they will fit without cutting into the hood supports. I'm only really doing this for the trail since thats when the heat really builds up causing engine temps to hit +/- 235*. On the street engine temps stay at 200-210*. But there wouldn't be any NEGATIVE effects to engine performance by having the vents towards the back would there?

I'll be tearing into this project soon - if weather cooperates with me tomorrow.

 

[yellowxj]

I used sofit(sp) vents bought at home depot, aluminum, louvered, with a screen on the back. Nice and slim and around a dollar each I think. Can see plumes of heat rising on our hot slow florida trail rides. Wired my fan to run full time too. Every little bit helps.

 

[Maximus]

I have plans with the blower vents from a boat that are painted black. My idea is to put them about 1/4 way back from the front. The difference I am doing is to install two small 4" fans that I can turn on manually that will pull air out of the engine bay. You can also reverse one and make one push while the other pulls. I have not yet done the mod so this is all theoretical. Just another idea.

 

[bbaker80]

I was sitting next to a mid 80's Trans Am, and I happened to look at the hood. The vents on the hood looked perfect for both high and low speed cooling. There was a big pair up near the front of the hood behind the radiator, and a second smaller set back and to the sides. Just a thought, I'll look next week while I'm pulling a fan and axle shafts next week.

 

[EricsXJ]

I finally got mine in today. I am still working on the covers and then I'll do a write up. They are the Lebaron Turbo/New Yorker vents.

 

[Gojeep]

You know you can improve suction on any vent position but attaching a small flap on a angle in front of the vent. What this does is creat negative pressure behind it as the air flow is forced off the hood by the flap creating a venturi effect. Take a look at the Trans Am side vents to get a picture of what I am talking about. This would also help keep water out at speed too but not much help at other times!

These may look alright on the hood as well!

 

[EricsXJ]

Just to update you guys, I finished my vents and have an extensive write up on my site. http://www.ericsxj.com/vents.htm I'm very pleased with the vents I installed.

 

[GPRSDLYT]

very nice!

 

[et89xj]

I had a set of the Trans-Am hood vents on my old hood that AJ form AJ's Offroad Armor.com has now. They worked and looked GREAT. The hood I have now has an early '80s 'stang hood scoop and early LeBaron fender faux vents cut open, they work pretty good, but I will be soon adding the Trans-Am upper hood vents in almost the same spot as the Trans-Ams have them located. I'm hopping this will help a little with higher speed venting of warm air. Wish I had pic to post of both hoods but lost all of them when the shops computer crashed last week...andy

 

[mudder]

My jeep runs a little hot on the trail and when going up hills, It doesn't help that its black. I was thinking about putting some vents on probably household ac vents. The radiator is a couple of years old, the system has been converted to open. the cooling system seems fine. I also have a manual switch for the newer style electric fan.

I would put the vents on the leading edge of the hood, which would be a low pressure area at highway speeds and right above the gap between the radiator/motor for good efficiency at slow speeds. What are your thoughts would it make a diffrence?

lol how did this post get here? it's over a year old :dunno:

 

[wascobi]

I had a set of the Trans-Am hood vents on my old hood that AJ form AJ's Offroad Armor.com has now. They worked and looked GREAT. The hood I have now has an early '80s 'stang hood scoop and early LeBaron fender faux vents cut open, they work pretty good, but I will be soon adding the Trans-Am upper hood vents in almost the same spot as the Trans-Ams have them located. I'm hopping this will help a little with higher speed venting of warm air. Wish I had pic to post of both hoods but lost all of them when the shops computer crashed last week...andy

I looked at some of those t/a vents and they seemed to have a twist in them to match the body line. any problems fitting them flush? did you have to open the actual vent part? been thinking about those for a while now!

 

[89TrailXJ]

i have some off of a 96 pontaic gtp that i've installed in both of my xjs and it makes a big difference.....but it does take longer to heat up.if interested i do have some extras for sale.email me if interested.

I have the same vents that I am working on installing.

 

[Gojeep]

I added a little write up on my site with different setups around for hood vents. Might get a little info there too.

 

[GI-John]

What ever happened to removing the weather strip and bending down the lip where the hood and cowl meet?

I've had that "mod" for 2 years and have no problems. Underhood temps are low, and I'm using a stock thermostat.

I guess you all like to cut sheetmetal.

 

[89TrailXJ]

hmm never heard of that one before. I am going to have to try it.

 

[CheapXJ]

I guess you all like to cut sheetmetal.

YES DAMMIT!!!!

and I like my vents too!

 

[OT]

Don't know if it'll work but I figure if I put 1/2" to 1" spacers between the hinges and hood, it'll vent alot.

 

[Gary E]

Don't know if it'll work but I figure if I put 1/2" to 1" spacers between the hinges and hood, it'll vent alot.

nope thats a high pressure area, it will mildly forcefeed the engine compartment and probably hurt by disrupting the flow past and underneath the car. To be effective you want them up in the front or near the sides these are areas with relatively high velocity areas which equals lower pressures. Look at the 5.9 zjs their vents are towards the front on the edges of the hood.

I think they help, certainly did not completly solve the problem. A lot of heat definatly boils out of them. They are right over the radiator so you can feel lots of heat coming out of them with the fan blowing.