Thread Tools Display Modes
Old 01-19-2019, 09:08 PM   #1
Senior Member
Railvan's Avatar
Join Date: Jun 2007
Posts: 196
Hood louvers verses reverse scoop?

I have read through this thread:

I am considering adding louvers as a way to keep engine water and oil temps and trans temp down.

But I was wondering about this idea: A "scoop" installed in reverse, as close to the top of the hood as possible. The idea is to let hot air out, but keep rain out as much as possible. I know everything under the hood gets wets, very wet, when driving in rainy weather. A Subaru WRX-type hood scoop looks like it could be mounted on top of the hood without too much work. Not sure about the radius of the hood verses to bottom shape of the scoop. The long top extension on this scoop would keep rain falling down wards from going into the engine compartment. The small lip across the bottom of the opening would keep water from running into the scoop.

Maybe louvers are better? Just daydreaming.

Honestly, it seems like the louvers work, I just don't like the look of them. Lol.
Attached Thumbnails
Screen Shot 2019-01-19 at 8.01.24 PM.png  

2006 Ford RB, 6.0 diesel, SMB 4x4, RB50
Railvan is offline   Reply With Quote
Old 01-19-2019, 09:13 PM   #2
Senior Member
rallypanam's Avatar
Join Date: Feb 2013
Location: San Francisco/Nevada City
Posts: 3,706
I put the louvres on. They did nothing as far as I can determine.

rallypanam is offline   Reply With Quote
Old 01-20-2019, 05:07 AM   #3
Senior Member
shenrie's Avatar
Join Date: Nov 2012
Location: boise idaho
Posts: 2,363
maybe hit up the the member who started this thread and see if he’s got an update with his results?

There’s also a thread where boywonder and 1der did some real world testing with some fancy tooling to see if the louvers would help or not.
"understeer is when you hit the wall with the front of your car, oversteer is when you hit the wall with the rear of your car, horsepower is how hard your car hits the wall, and torque is how far your car moves the wall."
shenrie is offline   Reply With Quote
Old 01-20-2019, 10:20 AM   #4
Senior Member
Join Date: Jul 2011
Location: Flagstaff, AZ
Posts: 1,811
I have hood louvers. I'm not sure they do anything for actual running temps but I do think they help with dispersing under-hood hot air. No empirical evidence for that other than feeling the hot air coming out when stopped with my hand. It's that hot environment that's cooking the wiring harness and other electrical components.
2005 E350 RB 6.0 PSD for extended fun
1989 Landcruiser FJ62 for local fun
2011 VW TDI Golf for hwy fun
JoeH is offline   Reply With Quote
Old 01-20-2019, 12:29 PM   #5
Senior Member
carringb's Avatar
Join Date: Jan 2009
Location: Corvallis, OR
Posts: 4,679
Reverse hood scoop will push air in, while moving, because the windshield cowling is a high pressure area. Subaru does this because that's where the intercooler is.

If you did this on your van, you'd basically be bypassing air around the radiator. Of course, when stopped, it will blow hot air out that cowling. Right into your A/C intake....
2000 E450 dually V10 wagon
carringb is offline   Reply With Quote
Old 01-20-2019, 12:52 PM   #6
Senior Member
1der's Avatar
Join Date: Apr 2013
Location: San Francisco, CA
Posts: 2,290
Based on the testing boywonder and I did, it is my feeling the louvers on the hood do nothing to “extract” or introduce more air into the engine compartment while moving. No question they allow heat to escape when stopped.

Extractor vents on the fenders might do something while moving and would help with heat escaping at rest. We did not test that area but it seems logical it would be a lower pressure area across the outer sides of the van front fenders than underneath the hood. Keep in mind there are other considerations of under hood airflow such as across the exhaust manifolds and top of the ttransmission.

The reverse scoop idea at the rear edge of the hood probably would not create much extraction either, it is a high pressure zone when moving. (edit:Just saw carringb’s post after posting this, same idea)

A front facing scoop behind the radiator would increase pressure behind the radiator and would likely reduce airflow through the radiator. I would be very reluctant to do anything that could potentially reduce the airflow, while moving, through the radiator and other coolers that face forward behind the grill. Creating a lower pressure behind the radiator would be helpful. The air deflector/dams that hang down below the bottom of the radiator would help do that.

Just my two cents

Beastie 3: 2002 7.3 EB Cargo: Agile TTB, CCV Mid Top, Custom Walk Through, Lots of stuff added.
1der is offline   Reply With Quote

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Powered by vBadvanced CMPS v3.2.3

This website is not affiliated with or endorsed by Sportsmobile SIP or any of its affiliates. This is an independent, unofficial site.

All times are GMT -6. The time now is 08:22 PM.

Powered by vBulletin® Version 3.8.8 Beta 4
Copyright ©2000 - 2020, vBulletin Solutions, Inc.