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Getting rid of under bonnet heat
mad-butcher - 8/4/09 at 05:00 PM

Thinking of putting some holes/vents in the bonnet to get rid of some of the heat. Any suggestions more than welcome, was thinking of 4 holes about 3" in diameter one above each exhaust pipe and two similar to the metro style up by the scuttle

many thanks
tony


omega0684 - 8/4/09 at 05:07 PM

have you got your exhaust primaries wrapped in exhaust insulator wrap? metro style vents are a good idea and you will get a warm breeze on you too



[Edited on 8/4/09 by omega0684]


Humbug - 8/4/09 at 05:09 PM

quote:
Originally posted by omega0684
have you got your exhaust primaries wrapped in exhaust insulator wrap? metro style vents are a good idea and you will get a warm breeze on you too


...and boiling coolant if a hose goes.

I've got vents on the sides of my bonnet towards the rear


Badger_McLetcher - 8/4/09 at 05:13 PM

The best thing to do is try to promote airflow through. Don't put in scoops without vents for it to go out of I'd be tempted to do as Humbug has and put some vents down the side and then if that's not enough add in a scoop to direct more air in. Also insulating tape can work really well


jollygreengiant - 8/4/09 at 05:59 PM

With the help of TrevD (he folded the metal to my spec) I fitted a heat shield around the Exhaust. This gives 3 functions, it protects against brake fluid being thrown onto a Very hot exhaust (major cause of under bonnet fires in accidents), It protects coolant hoses and electrical cables from the excessive heat, and it ducts air flow straight over the exhaust pipes and straight out of the side.
exhaust heat sheild 2
exhaust heat sheild 2


These above functions combined with the metro bonnet louvres keep the under bonnet quite cool.
OS bonnet & shield
OS bonnet & shield

another pose
another pose


bassett - 8/4/09 at 08:26 PM

Hi, id go for some sort of louvres that you can attach from the underside of the bonnet so air flowing over sucks air out from the engine compartment.


wicket - 8/4/09 at 09:45 PM

Here's mine Rescued attachment Bonnet Vents 1a.jpg
Rescued attachment Bonnet Vents 1a.jpg


austin man - 8/4/09 at 10:14 PM

we modified the side panels on an MK Indy resulting in a 10 degree temperature drop.

The side panels have been cut and moved outward by an inch similar to the DAX rush. this allow a free flow of air under the bonnet and also removes the hot air hitting the bulkhead.