Thread: Will a bonnet scoop reduce heat in the engine bay?

Originally Posted by DiscoMick

Here are some pics of Defender vents, but I have no idea if they would work on a Disco. I don't understand aerodynamics.

https://www.seriesdefender.com/wingtop-side-vents.html

The milled alloy ones looks awesome..unfortunatly none look good on Rangie bonnet sides, however the design i like and want to do something similar..anyone know any good alloy millers.

Originally Posted by blackrangie

Progress on dummy RRC Bonnet..thoughts

Looks good. Is it rear facing? I can’t quite see on my phone. Where did you get it? Ta.

Originally Posted by rar110

Looks good. Is it rear facing? I can’t quite see on my phone. Where did you get it? Ta.

Front facing..still in development

Originally Posted by DiscoMick

Here are some pics of Defender vents, but I have no idea if they would work on a Disco. I don't understand aerodynamics.

https://www.seriesdefender.com/wingtop-side-vents.html

They are the wingtop vents not side vents, but could be modded to fit in the side guards. You can buy standard versions a lot cheaper. Usually one is for the fan / air con air intake. On Australian models on the passenger side. The drivers side is usually blank. Not usefull as vents on a Defender as will allow too much water ingress. The air con one has a drain valve.

This is an example of a Defender side vent, but I'm not sure if it would work on a Disco.

Land Rover Defender KBX Sport RHS Side Air Intake Vent Java Gloss Black Standard | eBay

You're right the Defender wing top vents are a ventilation/air con intake (on the passenger side in right hand drive) and a fake on the other side, but I guess they could be used for exhausting hot air too.
The open one can also let in rain. There is a drain, but some people fit a snow cowl to keep out the water. Here's mine. I wonder how it would look on a Disco?

getting a bit hi-tech here, but was thinking that my madman 2 has the spare wire which gets a positive signal when one of your selected parameters reaches your pre-set limits. could make some louvres with an actuator that opens and closes them as coolant temp gets to a certain range. thus allowing your engine to get to operating temp same time but then the louvres open to allow for heat dissipation and more flow. was just scared that too much airflow through rad would take longer to warm up and possibly run at cooler than normal temps. probably not though. the other advantage could be that you have an override button which could close if it's raining or when engine is off and cool.

would be much easier ways to do it but i like building stuff like that. would water ingress matter so much? providing that its not going over something electrical?

i like the idea of a louvre or scoop directly above the exhaust/turbo. that was my original plan. the get airflow around the inlet pipes to IC and also exhaust and then out the louvre. also when car if off, the heat soak around exhaust would go straight up and out.

first thing i would do is ceramic coating and bigger IC. then aluminium IC pipes. then lastly some kind of scoop or louvre.

Front facing..still in development

Looks great but I don't think it would achieve anything but looking great.
The efficiency of a radiator depends on the pressure drop front to back.
if you are stuffing air in then the pressure drop will be less.
It will let hot air out when stopped though so that may help.
As I said earlier I think The Top Gear " vents" look the most effective .ie if there are scoops into the engine bay to let air out near the radiator.

On my old 81RRC I made up an alloy scoop under the bumper to replace the plastic seal . This was in Saudi but the best thing I did for slow going was to fit a humungous Mercedes cooling fan pushing through the RAD to replace the little aircon ones.
Regards Philip A

Originally Posted by PhilipA

Looks great but I don't think it would achieve anything but looking great.
The efficiency of a radiator depends on the pressure drop front to back.
if you are stuffing air in then the pressure drop will be less.
It will let hot air out when stopped though so that may help.
As I said earlier I think The Top Gear " vents" look the most effective .ie if there are scoops into the engine bay to let air out near the radiator.

On my old 81RRC I made up an alloy scoop under the bumper to replace the plastic seal . This was in Saudi but the best thing I did for slow going was to fit a humungous Mercedes cooling fan pushing through the RAD to replace the little aircon ones.
Regards Philip A

I think this is actually a good idea, upgrade current small fans as im sure they are hopeless, i think certain defender builders in the US do this