Bonnet Vent

[BigJon]

Here is todays little project. Perhaps it will help with overheating issues.
Vent is an air intake from a Discovery 3.


http://img294.imageshack.us/img294/945/dscf2800tk9.jpg (http://imageshack.us)
[IMG]http://img294.imageshack.us/img294/5363/dscf2803eu3.jpg (http://g.imageshack.us/img294/dscf2800tk9.jpg/1/)



[URL=http://imageshack.us][IMG]http://img294.imageshack.us/img294/4566/dscf2804bd6.jpg (http://g.imageshack.us/img294/dscf2803eu3.jpg/1/)
http://img294.imageshack.us/img294/dscf2804bd6.jpg/1/w640.png (http://g.imageshack.us/img294/dscf2804bd6.jpg/1/)

[PhilipA]

Even if it doesn't do anything it looks great to me.

It will probably help to let heat soak out when you stop.
Regards Philip A

[timaus13]

I must say thankyou, what a terrific idea;), I can never think outside the square like that. (to coin a frase).

Looks like it was fitted at the factory.

PS also love the rest of ure range Rover.:D
cheers mate

[BigJon]

Thanks guys.

I have had the vent for a few years (left over after a snorkel installation), but only fitted it today.

I figured after painting the bonnet late last year and then fitting the flares this year, one more piece of cutting and fitting wouldn't hurt!

[Grimace]

that looks great!

[dungarover]

Not bad at all, plenty of airflow under the bonnet there :)

See you have flares on now, look like the Paddocks ones from the UK :cool:

Trav

[Scouse]

See you have flares on now, look like the Paddocks ones from the UK :cool:Keep up Trav :p.

http://www.aulro.com/afvb/general-chat/71483-what-do-when-you-have-sick-engine.html

[dungarover]

Yeah whatever :angel: have to be better than the fiberglass crap ones that I had :mad:

Trav

[Waxenwane]

Looks great, Ive thought of doing it myself and didn't want to fork out the cash on vents because of a whim.
How deep are they?
It would be interesting to mount a thermo probe to monitor how much heat is getting out now. The old 2 door rear vents where a great idea, just looked pox.
Nice work.:cool:

[Bigbjorn]

If you have a major overheating problem and your existing cooling system is in good condition, & the engine is in tune, then only three things will help. A greatly increased radiator frontal area, a thicker radiator core with more rows of tubes unless you get so thick you are restricting air flow through the fins (ask M.A.N. trucks about this), or greatly increased air flow through the fins. Hope your little vents work.

[abaddonxi]

That'll confuse 'em.:D

Simon

[buzz66]

Here is mine.
Look Familar.

[Rangier Rover]

It looks the part:) I have a pair of RRS vents for mine but still haven't put them in yet.:(
Tony

[HangOver]

they look real good, whats a set of D3 or RRS vents cost out of interest?

buzz66, do the vents actually help cooling much or are they just for bling ;)
just wondering too what that bar is fixed to your wing with metal straps and that, what lookslike a small brass radiator?

[rovercare]

If you have a major overheating problem and your existing cooling system is in good condition, & the engine is in tune, then only three things will help. A greatly increased radiator frontal area, a thicker radiator core with more rows of tubes unless you get so thick you are restricting air flow through the fins (ask M.A.N. trucks about this), or greatly increased air flow through the fins. Hope your little vents work.


Have to concour here, a rover V8 in a rover once had the capability to stay cool, now it doesn't, hence something is wrong, until you find what it is, you merely trying to mask the problem

Or just pull it out and put something worthwhile in:eek:

[BigJon]

Quite a bit of hot air comes out of the vent when stationary and idling.

My radiator core is quite new, but of dubious quality. The radiator man that fitted it wasn't very impressed with it. Not many FPI, but it was free (warranty core).

I think there isn't much doubt that my 3.5 is pretty crook. Other threads are proof of that.

[cockie55]

I have no engine cooling issues with my D1 but I did some testing of engine bay temperatures using a digital readout in the cab with a sensitive type K thermocouple probe.

I found movement of the vehicle quickly allowed heat to escape out of the bottom of engine bay as it is designed to do. However stopped in traffic for long periods or during heavy slow going say towing in deep sand temperatures the engine bay hit 80 degrees C with a bullet and got higher close 100 degrees C when ambient temperature is high. Temperature was a lot lower in vicinity of viscous fan but higher at the rear and top of engine bay. Alternator windings, hoses and electric looms are frying from this sort of temperature.

This was my solution. It is a bonnet mounted “extractor” fan. It is connected to a Davies Craig Thermal Switch set at 75 degrees C to cut in and cuts out at around 60 degrees automatically. It is also set up so power is maintained to the fan for 3 minutes after ignition is turned off using a kit timer from Jaycar.

Bonnet Vents (http://www.pacet.co.uk/BONNET.HTM)

The stock vent while very well designed looks like a toilet exhaust sitting on my D1 bonnet so I manufactured my own out of fiberglass and some alloy mesh and modeled on a Hilux vent.

Location and vent design is such that I have no issues with heat transfer to interior cabin vents. I designed the vent so at speed it maintained pressure at the top of the engine bay and so not diminish the natural flow out the bottom of engine bay that no fan or vent can replicate.

[PhilipA]

Now THAT is what I call dedicated.
Only thing against I can see is that you would have ram effect while moving which may reduce the amount of air through the rad, due to a smaller pressure drop.
I had a Porsche 924 turbo at one stage and it had a NACA duct near the turbo. Took me a while and some heat haze coming out to figure that it was to allow the heat soak out after stopping. Because it was recessed it would not have drawn much air while moving. Supported by below.

NACA duct - Wikipedia, the free encyclopedia (http://en.wikipedia.org/wiki/NACA_duct)

Regards Philip A

[cockie55]

".......you would have ram effect while moving....."

PhilipA I have yet to do a pressure test but I dont think any ram at all (other than just a fraction +) on account of the waterproofing design attached to the vent.

The extracted air has to come up and then down under the skirt to the outside OR water/introduced air would have to travel in up over and down into the fan. If you look at pic 1 you will see traditional ram opening has been reduced in height with a baffle on the top to both waterproof and stop the ram effect you speak of. Plus you will see it is located at rear of engine bay where the heat is and to not impede pressure differential for radiator air flow

I am on lookout for some D3 vents as BJ has done

[BigJon]

In addition to the vent I also replaced the rubber seal between the radiator suport panel and the radiator. The 30mm body lift had left a little gap there. The new rubber seals the gap completely.

Driving from Horsham to Adelaide last Sunday (40 plus degrees) with the A/C on and speeds up to 110 kph saw the temp barely abaove half.

[2_door]

In addition to the vent I also replaced the rubber seal between the radiator suport panel and the radiator. The 30mm body lift had left a little gap there. The new rubber seals the gap completely.

Driving from Horsham to Adelaide last Sunday (40 plus degrees) with the A/C on and speeds up to 110 kph saw the temp barely abaove half.

any pics??? mine has a 30mm body lift but it has a mesh grill in front of the radiator that sort of fills the gap at the top btn the radiator and support panel.

would be interested to see how yours fits :D

[BigJon]

I can't do pics at the moment, I am 1500 km away from the vehicle! I will try to remember when I get back to Adelaide.

There was a rubber seal from factory, but it didn't fill the gap after the body lift. The replacement is similar (pinches over a lip in the metal) but is deeper to fill the gap.

[LOVEMYRANGIE]

The heat issue is why I fitted thermo fans and did away with the viscous fan.
Regardless of where you are and what speed you are doing, the fans, particularly when idling, pump huge volumes of air thru the engine bay resulting in a big heat haze rising from under the car when stopped at lights.
Not to mention that in summer when the viscous spends most of its time locked up, is much more quiet and makes a big difference in engine load when accelerating!

[buzz66]

The only thing to consider with Thermo Fans is the Alternator will struggle with Airccon,Thermo Fans, and a Flat Aux Battery in Summer. If you have no Aux Battery and Fridge, all will be well.

[brend0n]

Yeah I've been working on doing the same thing.. except my vent is back further in the next panel (the windscreen bit).
http://i70.photobucket.com/albums/i107/gj_wagon/P11-06-10_1047.jpg
same vent, they bloody look good, mines not finished yet though.
found out after i installed it that its bnot all that hard to take that panel off so Im redoing it now.