Bonnet Vents

[cb750]

Hopefully these will help remove some of the excess heat from under the bonnet, even have nice stainless safety edges!!

 

£2.99 off eBay. Bought another pair of 3 louvre ones for £2.99 as well. Just need a clean.

 

 

 

[maccavvy]

proper bargain...

[Guest Pauljordan]

Have you got the item number for fleabay I need some of these?

Ta PJ

[cb750]

Sorry, no PJ these were off somebody that had taken them off his boat and nobody else bid so I was lucky! I think they are normally about £17 each. Search on eBay for stainless boat vents.

Rob

[tractor]

had a look on flebay cant find anything that cheap

[cb750]

I don't think you will! I was lucky, the seller was hoping for more but he didn't get any more bids. I did spot one 3 louvre stainless vent that went for 99p earlier this week though.

[Guest Pauljordan]

Dam must keep searching ...... Got to cool mine down somehow. Thinking about moving rad forward and fitting electric fan.

PJ

[cb750]

My rad is in the nosecone with a Spal electric fan but the heat is just passed back into the engine bay. It could do with being ducted out before it gets to the engine bay but I can't see an easy way of doing it.

[Guest 2b cruising]

My rad is in the nosecone with a Spal electric fan but the heat is just passed back into the engine bay. It could do with being ducted out before it gets to the engine bay but I can't see an easy way of doing it.

Hi, can't you put a home made duct on the radiator to direct the air flow.

I have my rad and oil cooler further back near the engine. A scoop underneath extending the angled cross member to force the cold air direct to the rad.

I then have a gap at the back of the bonnet to let the air get out.

It was badly overheating when I bought it but I have no problems now.

[Guest mower man]

Dont forget that the hot air need to get out of the engine bay I had two vents on the side of the bonnet not to get cold in but to get hot out !! Any thing to stop air getting out is your enemy !!! mick

[cb750]

Got round to fitting the vents. I know they are in "backwards" but the idea is that they will draw ambient air in and force the hot air out of the bonnet louvres. I don't intentionally intend to drive in wet weather so dragging water in wont be a problem. Been out in it and the under bonnet temperature is much improved.

 

 

[Guest mower man]

Sorry but that does not work ,vents are fitted to improve cooling by drawing hot air out turn them round mick

[richardm6994]

Like mowerman says....they need turning around so that they draw hot air out of the engine bay.....I don't think they would work anywhere near as efficient for pulling air into the engine bay; only the front louver is doing anything and it is very small and doesn't protrude far enough into the air flow - that's why air 'scoops' are generally bigger and protrude right into the air flow.

This is from a job I did for another member;

Edited September 1, 2015 by steamer

[Guest 2b cruising]

It is absolutely no good creating even more pressure under the bonnet than is already caused by the forward motion of your car.

These louvres work by not just allowing pressurised air to escape, but they also create a vacuum as the outside air rushes past them, further helping with the exhaust of the hot air.

It is a simple job to turn them though.

[cb750]

Thought these would be the replies we would get! All I will say is that they have worked so far that way and they are forcing the air out through the TOP LOUVRES in the bonnet and the temperature has really fallen. The forward facing louvres are staggered out into the air flow due to the taper on the bonnet. We are going to give them a further trial and measure internal temperatures versus ambient and then turn them round and do measurements again and see what we get.