givemethebighammer
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| posted on 18/7/06 at 10:20 AM |
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Vent positions
Following on from Mark Allanson's post on under bonnet temps, some of the replies made me think that although I have managed to get lots of air
into the engine bay via my funnel in the nosecone I should be thinking about getting it out somewhere. The engine does not overheat but the footwells
do get hot etc. From what I understand vents in the top of the bonnet are only effective when stationary or at low speeds. Ones in the sides work well
at higher speeds. My one concern with ones in the top is that fumes from the engine bay will be blown back over the aeroscreen into the car (not
nice). I think that maybe ones in the sides won't have this problem. See the picture below what I am thinking, the thing is do I go for sides,
top both ?.
[Edited on 18/7/06 by givemethebighammer]
 
Rescued attachment vent positions.JPG
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Hellfire
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| posted on 18/7/06 at 11:24 AM |
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Personally, I'd just go for the top ones. The only time the temperatures really rise on our Indy, are when stationary or moving relatively
slow.
The only other time they rise are whilst thrashing it on track on hot days.
Phil
[Edited on 18-7-06 by Hellfire]
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givemethebighammer
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| posted on 18/7/06 at 12:21 PM |
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Phil, have you noticed any engine fumes being blown into the car after cutting the vents ?
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Kissy
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| posted on 18/7/06 at 12:25 PM |
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What happened to what exits underneath? That's what all tin-tops rely on.
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givemethebighammer
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| posted on 18/7/06 at 01:58 PM |
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quote:
Originally posted by Kissy
What happened to what exits underneath? That's what all tin-tops rely on.
I guess it is all going underneath and down the tunnel. That's why the footwells get hot. Surely it must be better to get the air out by venting
it ?
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Marcus
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| posted on 18/7/06 at 02:42 PM |
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quote:
Text My one concern with ones in the top is that fumes from the engine bay will be blown back over the aeroscreen into the car (not nice)
What fumes?
If all your breathers are working properly, you should only get hot air.
Marcus
Because kits are for girls!!
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givemethebighammer
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| posted on 18/7/06 at 03:14 PM |
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quote:
Originally posted by Marcus
quote:
Text My one concern with ones in the top is that fumes from the engine bay will be blown back over the aeroscreen into the car (not nice)
What fumes?
If all your breathers are working properly, you should only get hot air.
True, but as I've never had my head under the bonnet when the car is moving how will I know ? I don't want to cut a hole in the bonnet to
find out.
However I suspect it'll be OK
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Marcus
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| posted on 18/7/06 at 04:08 PM |
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Fair enough - reminds me of old pictures of racers in the 1920s / 1930s with black faces and white eyes due to the oil and crap coming out of the
engine bay
Marcus
Because kits are for girls!!
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Smartripper
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| posted on 18/7/06 at 04:22 PM |
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Hello,
I got vents on the side of the bonnet and it's very effective.
The zx12-r is a very hot engine but also when going slow in trafic jam the engine keeps cool below 95 degrees.
Before the tempeture rised too 115 degrees and the fan worked constant.
Daniel
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Hellfire
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| posted on 18/7/06 at 05:59 PM |
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quote:
Originally posted by givemethebighammer
Phil, have you noticed any engine fumes being blown into the car after cutting the vents ?
No. None whatsoever. 
Phil
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givemethebighammer
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| posted on 18/7/06 at 09:42 PM |
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thanks for all the comments, smartripper do have any photos you can post ?
thanks
I'm leaning towards the three circular holes in each side of the bonnet at the moment. However before I start cutting I'm going to look at
a few more photos.
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Moorron
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| posted on 19/7/06 at 12:14 PM |
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just the topic i needed. i want to get cold air to my filters and also hot air out as the engine bay gets silly hot (mainly after i have stopped). I
was going to go for the original mk indy one as my bonnet has nothing at the moment.
I have ordered some naca (spell?) ducts that i was going to fit on the side of the nose cone to get air into the engine bay, then just some holes at
the rear most part of the sides of the bonnet. Is this a good idea? someone told me that if the air hitting the lip of the nose cone becomes turbulent
it will have the oposite effect and creat a vacume at that point and no air will enter the duct. I am trying to keep it looking smooth (no sticking
out vents) and also trying to not have one ontop so water doesnt enter when its raining (stationary).
Any suggestions?
Sorry about my spelling, im an engineer and only work in numbers.
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Smartripper
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| posted on 19/7/06 at 04:14 PM |
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Hello,
I've posted a pictures off my car with the vents in it.
Daniel
 
Rescued attachment Vents.JPG
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Rob Palin
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| posted on 19/7/06 at 09:08 PM |
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quote:
Originally posted by Moorron
I have ordered some naca (spell?) ducts that i was going to fit on the side of the nose cone to get air into the engine bay, then just some holes at
the rear most part of the sides of the bonnet. Is this a good idea? someone told me that if the air hitting the lip of the nose cone becomes turbulent
it will have the oposite effect and creat a vacume at that point and no air will enter the duct. I am trying to keep it looking smooth (no sticking
out vents) and also trying to not have one ontop so water doesnt enter when its raining (stationary).
Any suggestions?
The ducts got their name from the predecessor to NASA. The aim is to use a sneaky bit of aerodynamic trickery to get air to go into a vent without
the need for a scoop sticking out of the bodywork. They do need to be a fairly specific shape and edge radius to work at their best but it will still
help.
I'm guessing you'd be putting them behind the location of the radiator anyway so perhaps somewhere around the same lengthwise location as
the headlights? That should be well away from any low pressure areas on the nose so you'd be fine.
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Peteff
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| posted on 20/7/06 at 10:11 AM |
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The ones on the top will suck air in behind the engine and add to the flow down the tunnel. If you are moving, any fumes will be gone far behind you
before you get chance to notice them, if you're standing still they will not blow back anyway.
yours, Pete
I went into the RSPCA office the other day. It was so small you could hardly swing a cat in there.
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givemethebighammer
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| posted on 31/7/06 at 10:05 PM |
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Went to whole hog and did both in the end. I used a 57mm holesaw, lots of tape and care. I then pressed some steel mesh (B&Q) into small "top
hat" shape (thanks for the tip Simon) using a male and female mould made from an offcut of 7mm lexan and a pair of G clamps. Sprayed them black
and glued them in with Tigerseal (as Hellfire did with theirs).
The result is the top of the engine bay is much cooler (I can actually touch the brake bias adjuster knob after driving now, before it was too hot).
Whether the car runs any better for it I don't know (too soon to tell), but it has to be a good thing getting the hot air out which the
modification is evidently doing.
(ps, photo taken with phone, wife has digital camera -I'll post a better pic when she gets back from the outlaws)
[Edited on 31/7/06 by givemethebighammer]
 
Rescued attachment vents.jpg
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Moorron
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| posted on 1/8/06 at 12:20 PM |
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NICE PHOTO, good to hear its worked also. Can u feel the heat with your hand whilst driving (leaning out of your seat)?
i have give up with the naca ducts, they would look to 'stuck on', if i damage the nose cone i will mould them in for a factory look.
I have drilled 3 holes where u have but only on the sides (for now) using a cone cutter (very smooth for cutting this stuff). Then i had a bright
idea, not sure if its too tacky but its undoable if it looks odd. i am in the process of welding 3 small alloy tubes to a plate that will stick out of
the holes angled backwards. sort of looks like an exhaust off a spitfire. I did this to b different AND to help the air eascape sue to the angle
creating a vacume around the vent. i was unsure from the shape of the bonnet if cold air would enter or hot air would exit, i dont know the airflow at
that point.
will post a pic later this week if i have them done.
Sorry about my spelling, im an engineer and only work in numbers.
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givemethebighammer
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| posted on 1/8/06 at 01:05 PM |
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quote:
Originally posted by Moorron
NICE PHOTO, good to hear its worked also. Can u feel the heat with your hand whilst driving (leaning out of your seat)?
Not a bad photo for a phone in a dim garage with no flash. I can't lean anywhere out of my seat with the six point harnesses on (I can barely
touch the top of the dash !). So I think I am just going to have to trust the fact that stuff like the bias adjuster feel much cooler that it is
working.
Good luck with your idea, hope works out the way you want it to.
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Moorron
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| posted on 2/8/06 at 09:16 PM |
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hers my latest work, i just hope it doesnt whisle when drivin lol
Sorry about my spelling, im an engineer and only work in numbers.
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Moorron
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| posted on 2/8/06 at 09:17 PM |
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erm.. how do i get it to work??
Sorry about my spelling, im an engineer and only work in numbers.
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se7ensport
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| posted on 3/8/06 at 03:28 PM |
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open the pic, right click, copy the bit which looks like this http://www.locostbuilders.co.uk/upload/DSC00743.JPG
then click on the icon that looks like a landscape (yellow background) and paste it in.
 
new vent1
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Peteff
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| posted on 3/8/06 at 08:40 PM |
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Please remember to resize the picture and edit out any ridiculous footwear such as pink flip flops and luminous striped socks before you upload
though.
yours, Pete
I went into the RSPCA office the other day. It was so small you could hardly swing a cat in there.
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Peteff
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| posted on 3/8/06 at 08:45 PM |
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You can also
add a picture from your hard drive as an attachment, using the function at the bottom of the reply box by clicking on the browse button, locating the
picture and adding it.
 
Rescued attachment horrible sock.JPG
yours, Pete
I went into the RSPCA office the other day. It was so small you could hardly swing a cat in there.
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Moorron
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| posted on 4/8/06 at 11:09 AM |
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lmao! thats my witch girlfriends foot honest.
i thought that was what i did, i will try again with some more pics later this evening. Cheers
Sorry about my spelling, im an engineer and only work in numbers.
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iank
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| posted on 4/8/06 at 11:23 AM |
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On another note are those headlights SVA safe? They look like some of of the motorbike lights (Premier and GTS sell/sold) that others have had
problems with.
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