hood louver cut out benefits?

[JonBishop]

im thinking of doing a mod to the hood louver and doing the cut outs... jus trying to get some information if the cut outs really helps with the heat and ventilation thank you :thumbs:

 

[rsc]

On mine they seem to shed engine heat better at a stop, and the engine bay heats up a little slower but overall I say save your time and money and dont do it. If you do it, make sure the louver vents face forward like little air scoops. The H3 exhausts air out the bottom, on the hwy the air being sucked out the top is counterproductive.

 

[Steve #1]

My plan (I'm waiting until it warms up so I can test and see if it works) is to modify the vents at the back of the hood to let more air pass. I am going to cut out a significant portion on the under side where the small holes are and cut out the area under the hood below the weather seal. It won't be a huge increase in air flow but should double what it is now. The up side to this is that the modifications won't be visually noticeable. I think removing the weather strip at the rear of the hood would also help with air flow.

 

[Paladine71]

Definitely runs cooler than before and heats slower, like rsc said. I did mine with almost no cost and am glad that I did; I haven't had any negative affect in the past year. I disagree with facing the vents the other way because you would pull in a lot of water.

 

[4speedfunk]

Considering the known issues with the 5-cly spark plug wells and coil packs, cutting additional holes could be a big mistake. In fact...I've pulled off my louver and I want to weld-up the factory mounting holes to help prevent water from dripping down onto the motor. If you remove your louver, you'll immediately find a bunch of leaves and pine needles that collect under the forward edge of it. Below the louver is a trough in the sheet-metal that captures and funnels water down onto the motor through some drain holes. I would like to re-contour the hood to eliminate this trough...however this looks to be quite a project. I got a buddy that does carbon fiber, and I'm trying to get him onboard to make me a flat hood. Probably easier in the long run, compared to working with steel. Anyway...the last thing an H3 needs is more water under the hood. If you can ventilate the area without introducing more rain water...then I don't see the harm.

I've never had any temps that I considered high enough to start cutting holes. There is an insulated hood liner available for the H3...some have it...some don't. This might help keep radiated heat from exiting the engine bay, if that's the concern.

 

[Expendable]

on the hwy the air being sucked out the top is counterproductive.

I'm curious, how is it being counter productive

 

[rsc]

I'm curious, how is it being counter productive

The H3 exhausts air out the bottom of the engine bay. If you open the top of the engine bay then it takes away from the pressure inside the engine bay that helps push air out the bottom of the engine to be sucked out by the negative pressure under the car. At first glance, it would seem that when you open the hood to get more air out that it has to be more efficient. What actually appears to happen is that as more air comes out the top, the pressure inside the eng bay drops and so does the speed and amount of air coming out the bottom. In effect you still get the same volume of air through the radiator but more air out the top and less out the bottom at hwy speeds. My hope was to have more air coming out the top at slow speeds off road and less heat build up under hood for quicker heat dissipation when parked on the trail or around town when its over 100 degrees outside.

 

[rsc]

My hood vents are outboard of the center panel so my coils stay dry. The airbox and fuse box are fairly well sealed so I dont worry about water coming in there. This positioning is mostly outboard from the major heat sources so this may be a reason for the less than hoped for efficiency. I dont really think thats the whole issue but rather that the air vents could be bigger and turned around like air scoops and not vents. Of course thats just my opinion based on observation without measurement (beside eng temp on a scan gauge).

 

[Expendable]

So the flow of air out of the engine bay from underneath is diminished. But I'm curious as to if you noticed any difference in temperature (not looking at gauge but looking at a scan tool readout such as a scan gauge), etc.

I have a 2004 Crown Vic as my daily driver and there are a few that I know have hood louvers and they have recorded differences at idle, low speed and high speed (freeway). These differences include lower coolant temps, decreased 'floating' feel of the front end due to the better air flow over the hood (air slides over air better)

then again they are two different vehicles designed totally different.

I was just searching hoodlouvers.com (which appears where your louvers came from) and they have a replacement for the factory plastic piece in the center of the hood.
http://hoodlouvers.com/product-category/wideflow-hood-louvers/

 

[Happy Hummer]

Interesting!

Chris

 

[rsc]

Yes, I have noticed a difference in temp on the highway using the scan gauge. Running with the louvers open ran about 5 degrees HOTTER than with the underside of the vent taped off. Crazy right? Around town at stoplights the eng temps DO come down quicker and you can feel the heat coming out but I dont see any "heat waves". In the rain on the freeway I can see the rain get "sucked" away behind the louvers which indicates a good negative area of air pressure to help suck air our from the engine bay. Overall you have to remember that the claims made by Run Cool are like the claims made by K&N for HP increases. Dont let me discourage you if you want to go this route, its fun and looks good (and is not a fake chrome stick-on) but it isnt magic either. I think that when wheeling it will help more than on the hwy though.

 

[Expendable]

cool, most people on the crown vic forums rely solely on their inferences and not actual data. I wasn't trying to argue. just curious to see if it helped one vehicle and didn't another. I also know not to rely on a manufacturer's data. it can be skewed so easily (#1 thing I learned in Advanced Placement Statistics when I took it in high school.

I do not plan to chop up my H1 hood to put louvers in. I do plan to put hood louvers on my Crown Vic though. they have been proven to work on multiple Vics.

 

[Paladine71]

Mine are directly over the front of the engine through a vented RealWheels louver. I have an Alpha, which is more protected from water. I'm happy with mine. You can feel the heat escaping through the vents, and it runs cooler all of the time.

 

[rsc]

That may be the ticket Paladine, your louver is over the highest heat area? Also, your slots in the louver are bigger which I like. Glad its working out. I am curious about Steve#1's idea with the rear hood trim removal.

 

[chad]

If I still lived in San Diego I would make my louver functional, the desert air is dryer and less rain. But living in fl I don't wang tons of pine needles and rain all over my engine area. I can foresee tons of problems in the future with that.

 

[Paladine71]

That's why I used two metal screens under the louver, a small one to stop debris and a larger one on top to protect the small one.