help with cooling the engine bay

[BAV1]

not sure if this is possible or legal (firewall) but any ideas would be appreciated

have been looking at fitting bonnets vents to help get rid of the hot air in the engine bay but worried about excess water getting in would this work and would it fail its MOT or anything

cheers

[wiggy]

would fitting a hood vent the 'wrong way round' not be a better idea or one of those electric fans someone had a thread about the other week. saying that though it gets hot in there but in the UK i wouldnt worry about it that much

[BAV1]

cheers wiggy was thinking that but dont really want to hack the bonnet to pieces and add loads of vents as i have plans to add a side mounted intercooler with scoop in the near future and dont want it looking like a scooby

was thinking 2 big holes maybe with a duct running to the top vent to ensure air is expelled using the convection of the air moving over the bonnet

[wiggy]

If you dont mind me asking why is it such an issue? Just curious as it gets really hot over here (40+ deg some days mid 30's others last summer..bit cooler this year tho) and i'm up and down some big hills here and its never had that much of a drama although i did need to raise the bonnet a bit last summer as i was getting a bit paranoid as we drove over here from dorset fully laden to the roof and with a large roofrack full over the alps. and as you said you are fitting other types of coolers to take the pain out of towing etc. someone with some more ideas should be about soon .

[Apache]

I dont think it is a big issue unless you're really hooning it up and down hills with huge loads - and if you are, the BEST thing to do is fit a tranny cooler.

As for excess water, I've been bonnet deep on several occasions and other than the engine getting muddy and the spotlamps filling with water, its not an issue.

[greecysurf]

You could do what i am in the process of doing, 2 round bell type vents, similer to the aftermarket ones for motorbikes, above and to the rear of the front wheel arch, with ducting to engine bay, we deal with tempretures upto and above 50 degrees here and so far touch wood, no overheating problems. in the mock up i done it lowered the temp by a couple of degrees around the engine, but it gets hot by the doors. You could also do a body lift, this helps the airflow around the the engine and lets more air escape. The engine bay is a confined area so its airflow you need to look at, on the surf valance at the front is some indents for fog lights, you could cut these out and using wire mesh and glass fibre, make another bell type duct, with tin cooker hood type ducting to improve the airflow.

[da SLUG man]

thought about modifying the bonnet hinge so it's slightly raised at the back?... just an inch.

[BAV1]

If you dont mind me asking why is it such an issue? Just curious as it gets really hot over here (40+ deg some days mid 30's others last summer..bit cooler this year tho) and i'm up and down some big hills here and its never had that much of a drama although i did need to raise the bonnet a bit last summer as i was getting a bit paranoid as we drove over here from dorset fully laden to the roof and with a large roofrack full over the alps. and as you said you are fitting other types of coolers to take the pain out of towing etc. someone with some more ideas should be about soon .

just paranoid as it seems to get ###### hot under the hood

[BAV1]

You could do what i am in the process of doing, 2 round bell type vents, similer to the aftermarket ones for motorbikes, above and to the rear of the front wheel arch, with ducting to engine bay, we deal with tempretures upto and above 50 degrees here and so far touch wood, no overheating problems. in the mock up i done it lowered the temp by a couple of degrees around the engine, but it gets hot by the doors. You could also do a body lift, this helps the airflow around the the engine and lets more air escape. The engine bay is a confined area so its airflow you need to look at, on the surf valance at the front is some indents for fog lights, you could cut these out and using wire mesh and glass fibre, make another bell type duct, with tin cooker hood type ducting to improve the airflow.

as far as i understand the dynamics of the air presure piping more air into the engine bay changes the air pressure which may have an adverse affect on air through the router maybe wrong ? my suggestion would work as the bonnet hinge idea but wi think look tidier

[wiggy]

just paranoid as it seems to get ###### hot under the hood

Aye it does!!! i have raised the back of the bonnet on mine and it helps more than you think but i like greecysurfs idea tho ............

[BAV1]

Aye it does!!! i have raised the back of the bonnet on mine and it helps more than you think but i like greecysurfs idea tho ............

any pics of raised bonnet mate

[wiggy]

Of the surf im 'fraid not and computer is a bit knacked at home (on the work one at the min) but can try and get one sent tommorow for you if you like but if you have ten min free just try it and see what you think. all you do is lift the bonnet undo the screws at the back (one side at a time) shove the washers on the original bolts (4) as they should take about 8 2mm washers each (if i remember right) kinda gives an effect like this but it looks a lot better on the surf http://img80.imageshack.us/i/10bc0.jpg/ and before anyone has a go it doesnt look boy racer on the truck and its just there to try and let some hot air out!........ from the surf that is

[Albannach]

as far as i understand the dynamics of the air presure piping more air into the engine bay changes the air pressure which may have an adverse affect on air through the router maybe wrong ? my suggestion would work as the bonnet hinge idea but wi think look tidier

What the hell did you just say?

[BAV1]

What the hell did you just say?

i read somwhere on here that adding say a foward facing scoop that spat air into the engine bay would infact increase the air pressure under the bonnet and affect the airflow through the rad not sure how accurate this is but can see the theory behind it

but what do i know thats why im asking

cheers

[Apache]

You do have to release the air thats coming in but you have a ###### great opening at the bottom of the engine bay, so I doubt a couple of little scoops will make any difference to 'pressure' at all. All this might be applicable when you reach 3 figure speeds, and will be important at 4 figure speeds, but at the 'ice floe' type speeds of a Surf it's likely not important.