Louvers for Bonnet

Dee See · Post by **Dee See** » Thu Mar 08, 2007 5:12 pm

A good source of supply for louvres are chandlers (or boat shops to you & me). There are a number in Dubai that sell the stainless steel types in many different shapes and sizes. Fibre glass and plastic types are also available.

Knowing what areas of your front end are subject to high pressure heat build up is the secret to using louvres. Simply screwing a pair down onto the hood won't nessesarily solve all of your heat retension issues.
You need to create proper air flow through the engine bay...hot air is created mainly via the radiator and is forced towards the rear firewall via the radiator fan/s.
Rising heat should be allowed to escape at the highest presure point ...not nessesarily the highest point on the hood.
On LandRover Defenders we've found that the highest presure point is actually down the sides of the wimgs and not on top of the bonnet. Nissan Patrols best location is on top of the bonnet closest back towards the windsheild with a smaller set mounted on the bonnet just behind the line of the radiator with the louvre facing forward to increase airflow into the bay. It's all about the airodynamics that are happening under the bonnet and not on the outside as many people think.
Louvres are sometimes applied because the owner rekons his truck will look the part, but for someone who knows better...they can look rediculas.

Bulldozer · Post by **Bulldozer** » Fri Mar 09, 2007 12:05 am

Dee See wrote:A good source of supply for louvres are chandlers (or boat shops to you & me). There are a number in Dubai that sell the stainless steel types in many different shapes and sizes. Fibre glass and plastic types are also available.

Knowing what areas of your front end are subject to high pressure heat build up is the secret to using louvres. Simply screwing a pair down onto the hood won't necessarily solve all of your heat retention issues.
You need to create proper air flow through the engine bay...hot air is created mainly via the radiator and is forced towards the rear firewall via the radiator fan/s.
Rising heat should be allowed to escape at the highest pressure point ...not necessarily the highest point on the hood.
On Land Rover Defenders we've found that the highest pressure point is actually down the sides of the wings and not on top of the bonnet. Nissan Patrols best location is on top of the bonnet closest back towards the windshield with a smaller set mounted on the bonnet just behind the line of the radiator with the louvre facing forward to increase airflow into the bay. It's all about the aerodynamics that are happening under the bonnet and not on the outside as many people think.
Louvres are sometimes applied because the owner reckons his truck will look the part, but for someone who knows better...they can look ridiculous.

Will done Dee See good work man, logic technical stuff we need to find out the Pressure/Ventilation area for the Cherokee & for the Wranglers which will lead us for the proper location to install the louvre

Jo · Post by Jo » Fri Mar 09, 2007 8:37 am

Good Comment Dee See!

you mentioned Defendes, whatsabout Discos? Any experience or suggestions?

Jo

Chuck · Post by **Chuck** » Mon Mar 12, 2007 5:06 pm

Hi,

i am half way thru with my new Grills. Last friday i was in the desert with the hole in the hood and the engine was about 15 to 20 degree cooler than last time.

The cutted hole

The Grill fixed with masking tape, ready for welding

The look from the inside. You can see the 4 nuts welded to the Grill ? These nuts will be used for fixing a pan under, if needed.

The look after welding from the outside

Now i just have to polish at the welding spots a little and give the hood for painting.

abdalla · Post by **abdalla** » Mon Mar 12, 2007 8:56 pm

hemm 15-20 C sounds good

Good luck Chuck

desertfalc0n · Post by **desertfalc0n** » Mon Mar 12, 2007 9:23 pm

Okkk,, so where do we fit this in our Wranglers,, the same place as the first picture....

Its looking pretty cool.. Will surely do this myself... If effect is effective.

Chuck · Post by **Chuck** » Tue Mar 13, 2007 8:25 am

abdalla wrote:hemm 15-20 C sounds good

Good luck Chuck

Fahrenheit, not Celsius ! Sorry for my unclear posting.

My car is from the US and my readings are in Miles and Fahrenheit.

Chuck · Post by **Chuck** » Tue Mar 13, 2007 7:28 pm

For the Wranglerfreaks there are some nice hoods availabe

from AEV Conversions

http://www.oman4x4.com/aevhood.htm

Its good to have that hood, if you have a monster like that under it

Dee See · Post by **Dee See** » Thu Mar 15, 2007 5:38 pm

Jo wrote:Good Comment Dee See!

you mentioned Defendes, whatsabout Discos? Any experience or suggestions?

Jo

I have a series I Discovery running a 4.6Efi V8. So far I havn't had the need to modify anything in the cooling system apart from keeping an eye on the coolant. (and even that never moves!).
If you are having cooling issues with your Discovery then louvres arn't the answer to the cure....finding the cause of the overheating will be the number one objective. My truck has run 220,000km from one end of Saudi Arabia to the furthest tip of the UAE without a single cooling problem......if it ain't broke then don't fix it!

My Defender is a quite highly modified 4.6Efi putting out 300lbs of torqe at the flywheel and just under the same in HP. I bought the engine from the Uk and had it on a dyno before having it flown over here for fitting. I bought an aluminium radiator for it whilst doing the initial instalation because I knew that the headers were going to make the engine run hotter in the bay for a start. The Old Victory Racing Team had a few ali rads lying around and I picked it up for 1000Dhs as opposed to the normal price of 6000Dhs!
I copied the side vents from the Saluki because we knew that they worked wonders on higher performance engines. Tim Ansel is the co-driver of the Saluki and comes from an aviation background. He did alot of study with aerodynamism and hence we knew where to start of modifying the engine bay and surrounding panels.

I can see why the yellow Jeep in the picture needs so much venting through his hood..... he has a massive 8274 Warn blocking the grill!

Regards.

DinoStroker · Post by **DinoStroker** » Sat Mar 24, 2007 12:33 am

Chuck wrote:Hi,

i am half way thru with my new Grills. Last friday i was in the desert with the hole in the hood and the engine was about 15 to 20 degree cooler than last time.

The cutted hole

The Grill fixed with masking tape, ready for welding

The look from the inside. You can see the 4 nuts welded to the Grill ? These nuts will be used for fixing a pan under, if needed.

The look after welding from the outside

Now i just have to polish at the welding spots a little and give the hood for painting.

I can't wait to see your hood (bonnet) when it's painted Uwe. Looks cool and it should reduce underhood temps. quite a bit.

Chuck · Post by **Chuck** » Sat Apr 07, 2007 1:22 am

The final result after painting of the hood

abdalla · Post by **abdalla** » Sat Apr 07, 2007 6:17 am

It looks nice Chuck 8) hope its doing what its intended to do

the paint looks nice too

Jo · Post by Jo » Sat Apr 07, 2007 7:16 pm

Hi Chuck,

looks good...

BTW, I have met Dee See three weeks ago. Very interesting...

:hat:

DinoStroker · Post by **DinoStroker** » Sun Apr 08, 2007 11:19 pm

Yeah, nice job Uwe! Very neat and subtle.