Hood Louvers Question

[nhrocker]

I've been thinking about this since I'm getting close to adding vents on my hood. I was thinking of it this way in regards to the rear 1/3 area:

Normally the back of the hood area is pretty much sealed, so any air coming through the radiator that gets to the back of the hood at any speed is forced to take a 90degree turn down and exit through the bottom of the engine compartment. With the addition of openings in the high pressure area in the back of the hood, air would be forced down the back of the engine compartment, helping to force the air currents coming from the front of the engine compartment down, where they would normally go anyway.

Does that make any sense?

 

[MogifiedXJ]

Hoods like this with the opening in the front allow air to be forced out at highway speed. Even sitting still you can feel the fans pushing air out of them...


Hoods like this...

Are made to draw air in at highway speeds...normally to feed colder air into the intake.

I would imagine the same thing would be true too for hood vents. You have a pocket of low pressure air at the front of the hood and a turbulent region of air swirling and coming down off of the windshield in the rear of the hood...that's why conventional cowl inductions work so well. At high speeds air is being rammed back down into them.

 

[ILLXJ]

Here's mine. I was more worried about overheating at low speeds. JIM

 

[GhostDakota]

We'll see how mine work when I get a chance to wheel. They passed the rain test last night... we had 2.07" of rain in 1 hour! And a good 4" of so of rain total yesterday. Engine was fine... I was driving through some crazy deep puddles (not flowing water) and the only thing that happened was the power dropped down most likely due to the alternator being soaked through.

 

[GhostDakota]

Here's the link to the search with 'em for sale:

http://www.quadratec.com/products/product_search.php?kw=louvers&submit=Go!

 

[Chris S]

My single rear facing scoop is right over the manifolds. My thought was to direct air flow accross the engine and out. It has had a very obvious difference in temperature when wheeling.

 

[Tugboat369]

This is the vents that I put in.

Be carefull when you install the vents not to cut the underhood bracing.

 

[jeep01xj]

These are mine Love them

 

[selarep]

Here's mine. I was more worried about overheating at low speeds. JIM

I've been thining alot about the whole 1/3 front thing and I think at higher speeds, the air would come in through the grille and out the top like jims pic above (greatly cool down the rad 'cuz to far back would actually collect heat from the manifolds), but for wheelin, it would be best to ahve some in the back too, more so on the drivers side sine everything is in that area anyways... right?

 

[ILLXJ]

Mine help on the trail also. When sitting at an idle you can see the heat coming out of them. JIM.

 

[Fish'nCarz]

I'm still worried about getting stuff wet that doesn't like water, and the aluminum turkey pans idea isn't something I'm excited about. What other options are there?

 

[ILLXJ]

With the placement of mine there is nothing under there to get wet. Maybe the plug for the electric fan but thats it. I have opened the hood after driving in a downpour & the PS pump is dry. I'm sure the air flow out of the vents helps. Even if it rains while parked the water will run straight down, so no worries. JIM.

 

[hadfield4wd]

I just drilled 20 holes with a hole saw in a square on each side of the hood near the windshield. I laid it out carefully and center punched each. Then I went to a sign store and got scrap magnets people use for door signs and put those on. I'll get pictures soon and post up.

Matt

 

[nhrocker]

I just drilled 20 holes with a hole saw in a square on each side of the hood near the windshield. I laid it out carefully and center punched each. Then I went to a sign store and got scrap magnets people use for door signs and put those on. I'll get pictures soon and post up.

Matt

Pics would be great! That's actually what I was thinking of doing. My dad owns a graphics shop, so I've got access to full rolls of the magnet. Instead of having to plan on where rain water (or snow) would go, I could just cover them when they're not needed. I just haven't been able to decide where to cut the holes. I was thinking of doing both the front and rear 1/3's and playing around with the magnets to see which areas worked best for each type of driving.

 

[xrayjeeper83]

OK to bring back to life a old thread, Im wondering how yalls rigs are doing now that it has been a few months since some of yall installed the louvers? Have we come to any agreement as were the best place is to install them?

Andrew

 

[hadfield4wd]

Pics would be great! That's actually what I was thinking of doing. My dad owns a graphics shop, so I've got access to full rolls of the magnet. Instead of having to plan on where rain water (or snow) would go, I could just cover them when they're not needed. I just haven't been able to decide where to cut the holes. I was thinking of doing both the front and rear 1/3's and playing around with the magnets to see which areas worked best for each type of driving.

since it was brought back up and I forgot before.

 

[hizzo3]

Hoods like this with the opening in the front allow air to be forced out at highway speed. Even sitting still you can feel the fans pushing air out of them...


Hoods like this...

Are made to draw air in at highway speeds...normally to feed colder air into the intake.

I would imagine the same thing would be true too for hood vents. You have a pocket of low pressure air at the front of the hood and a turbulent region of air swirling and coming down off of the windshield in the rear of the hood...that's why conventional cowl inductions work so well. At high speeds air is being rammed back down into them.

that is simmilar to how the AEV hood is like....seems that would work best... most the heat that is in the engine compartment comes from both the radiator and the headers.... headers can be wrapped. and the hood and direct the fans airflow from the radiator out the top....

 

[xrayjeeper83]

So what is the best way? Im looking more towards getting heat out during trail riding.

Andrew

 

[casm]

So what is the best way? Im looking more towards getting heat out during trail riding.

LeBaron vents seem to be effective enough - the large grille area coupled with hot air's natural tendency to rise drops temperatures quite a bit.

A few people have fitted electric fans to them to help expel more air, but I don't know how much more effective that is. My suspicion is that another smaller set of vents directly over the radiator would probably be as good.

 

[Tugboat369]

The under hood temp has been fine siting on the trail or sitting in traffic on a hot day. The temp has dropped from 20 to 45 degrees depending were under the hood. This test was done with a remote reading temp gauge and using my fathers stock 96 XJ. So the test was done on the same day with the same conditions and matching Jeeps.

My jeep has run cooler and stays about 180 no matter what. And that is not to cool to run normally. But has not changed the warm up time at all. That is something that I was worried about in colder weather.