JR20516V 6 Posted May 2, 2007 Need to get some heat out and was just wondering how peoples have done theirs. Have heard of several ways...all interesting. Would like to hear from others on how thay have done it. Cheers for any input. Share this post Link to post Share on other sites
sonofsam 5 Posted May 2, 2007 (edited) Only person Im aware of who has done this is Ant(maybe a search of his posts would reveal) for his Turbo and possibley Miles? on one of his customers car's? Had thought about it myself! at a guess You'd probably want some sort of spacers to lift the bonnet up off of it's original bonnet mountings? Edited May 2, 2007 by sonofsam Share this post Link to post Share on other sites
Paintguy 0 Posted May 2, 2007 How much do you want to raise it by? Because of the way the bonnet is bolted to it's hinges, there is a degree of play available without any modification, but I don't know if it'll be enough. No harm in trying it though: lift bonnet, slacken the 4 bolts a little, close bonnet (carefully!) & lift rear edge. If that doesn't lift it enough, there is some scope for enlarging the holes in the hinges to allow for more lift (square holes in this picture), but not a great deal. Having never tried it myself, I can't be much more help than that. Share this post Link to post Share on other sites
Baz 421 Posted May 2, 2007 Simple plates from the hinges to the bonnet? Share this post Link to post Share on other sites
Miles 331 1 Cars Posted May 2, 2007 I had mine lifted on my 309, I used bonnet pin's all round thou so the hinge wasn;t a problem but the running temps come down allot, The RS boy's use a Alloy spacer between the hinge and bonnet giving about 15mm extra height at the back so this can be done on the 205 in the same way, But beware (This is coming from the motorsport side of things) if this is done all the holes going into the cabin must be sealed in case of fire as it will be drawn in, not that this happens every day but it is a risk. Share this post Link to post Share on other sites
sutol 0 Posted May 2, 2007 Does anybody know about drawing heat out of engine bay using differing pressures. Like how to make the car suck out the heat by it's forward motion, if you know what I mean I have been trying to get some info on this subject for a while but no joy. It is poss by blocking front off except rad aperture to draw heat out under car, or so I'm told. Need a areodynamics geek to help I think Share this post Link to post Share on other sites
sonofsam 5 Posted May 2, 2007 I'll be going(or rather my bonnet)for something like this shortly: Will report back on its effects Share this post Link to post Share on other sites
Henry Yorke 269 3 Cars Posted May 2, 2007 Does anybody know about drawing heat out of engine bay using differing pressures. Like how to make the car suck out the heat by it's forward motion, if you know what I meanI have been trying to get some info on this subject for a while but no joy. It is poss by blocking front off except rad aperture to draw heat out under car, or so I'm told. Need a areodynamics geek to help I think You want to read up on NACA ducts as they are designed to create an area of negative pressure and therefore extract hot air out of an engine bay. Other things to look at are exhaust manifold heat wrap to keep the heat in the exhaust, not the bay. Oil coolers will dissipate a lot of heat from the block too so you have lower running temperatures. Share this post Link to post Share on other sites
Paintguy 0 Posted May 2, 2007 (edited) , The RS boy's use a Alloy spacer between the hinge and bonnet giving about 15mm extra height at the back so this can be done on the 205 in the same way, Really? I'm not normally one for doubting your word Miles, but the situation is very different between the Ford and 205 hinges. If I can explain it well enough, the hinges on the Ford bonnets attach in the same plane as it, i.e. the bolts go in vertically, so putting a spacer between the two does indeed raise it. But on a 205, the hinges fit 'side on' (bolts go in horizontally) so a spacer won't do the job. One idea I've been thinking of since my earlier post is similar to that which Baz suggests. Using some kind of plate to widen the area where the bolts attach to the bonnet. Like the blue area in the picture below: And on the subject of aerodynamics - isn't the bottom of the screen traditionally an area of higher pressure anyway? So maybe not the best place to site vents for extraction of underbonnet air. Edited May 2, 2007 by Paintguy Share this post Link to post Share on other sites
Paintguy 0 Posted May 2, 2007 You want to read up on NACA ducts as they are designed to create an area of negative pressure and therefore extract hot air out of an engine bay. I need to update myself then, as the NACA ducts I've always read about were designed to provide an air intake without disturbing the boundary layer over the surface. Mind you, it's quite a few years since I studied aircraft aerodynamics Share this post Link to post Share on other sites
sonofsam 5 Posted May 2, 2007 Really? I'm not normally one for doubting your word Miles, but the situation is very different between the Ford and 205 hinges. If I can explain it well enough, the hinges on the Ford bonnets attach in the same plane as it, i.e. the bolts go in vertically, so putting a spacer between the two does indeed raise it. But on a 205, the hinges fit 'side on' (bolts go in horizontally) so a spacer won't do the job. One idea I've been thinking of since my earlier post is similar to that which Baz suggests. Using some kind of plate to widen the area where the bolts attach to the bonnet. Like the blue area in the picture below: Yeah that's what I was thinking, very simple to manafacture too. Plate/spacer-same thing?! and it's what I meant in my first post Share this post Link to post Share on other sites
Baz 421 Posted May 2, 2007 Yep, easiest option, used to run a couple of plates about 2" on each hinge, bolted to the outer side, then a washer and bolts into the bonnet. The only downside is it tilts the front edge of the bonnet and looks a little out of place with the alignment to the grille/headlights, it's not major but you can wind up the stops if you care that much, or just live with it. Don't think i've got any pics but i'll have a looksee! Share this post Link to post Share on other sites
Baz 421 Posted May 2, 2007 Oh and of course reduces any air pressure build up in the engine bay aswell as letting heat out, which could *possibly marginally slow you down, acting as a wind break. And Naca ducts induce air not expell. Share this post Link to post Share on other sites
Miles 331 1 Cars Posted May 2, 2007 Best way is what Baz has talked about, basically the same idea as the spacer which I'm using on my 306 to start with. With the pin's it's as simple as this at the back Share this post Link to post Share on other sites
rescue dude 0 Posted May 3, 2007 Wouldn't just removing the long rubber seal at the rear of the bonnet help remove heat? Share this post Link to post Share on other sites
ashley peddle 3 Posted May 3, 2007 That's alot of pins Ash. yeh i know but i was told it would flap if i didnt use enough pins im actualy plahhing on adding another pin in the middle at the top as it flexes / rattels a bit Share this post Link to post Share on other sites
vern 0 Posted May 3, 2007 sonofsam I am sure paul (pd114c) had some of those vents on his old TT ask him if they were effective, before having them pressed in. Share this post Link to post Share on other sites
sonofsam 5 Posted May 3, 2007 Yeah, I wouldnt mind some first hand experience of thoses Louvres actually. At a fiver a pop it's not that cheap! Lucky the place that does it isn't far Interesting reading on raising the bonnet here : http://www.teirney.net/civic/BonnetSpacers.htm And vents here : http://autospeed.drive.com.au/cms/article.html?&A=2162 Share this post Link to post Share on other sites
