Posted by: Basil

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gonna investigate the reversing of the second nostril tomorrow- shouldn`t be too difficult, the bolts are symetrical on the template, so it should just be a question of turning it round and resealing round the outside

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Get the engine nice and hot (go for a drive not just standing still) , get someone to sit in the drivers set and give it a bit of a rev, then put your hand on the reversed scoop and tell us if you feel any heat coming out.

a couple on the oc have removed the rubber sealing strip from the back of the bonnets and raised the rear of it up for just that reason

I agree that removing the rear seal will allow hot air to escape, but I wouldn't be keen on adjusting the bonnet on any veihicle to sit up on the hinges either by adjusting bolts or fitting stand offs or spacing with washers, this is popular with boy racers and I've seen bolts shear in an impact and the bonnet strike the windscreen, so imo its not a good idea.
I've got a twin scoop and at idle there is a lot of heat forced out of the scoop by the viscous fan which will be the same if reversed but reversing the scoop may be counter productive whilst the truck is moving as at present cold air is forced through the second scoop and blown down over the engine and turbo before being expelled under the vehicle.

I see where your going Luke but IMO if you reverse the scoop you will loose the downforce from the second scoop , I think the same effect your seeking would be achieved by removing the seal at the rear of the bonnet which would probably provide a bigger air outlet than the scoop, apart from that reversing the scoop would look awfull

you know unless your going off road you can just leave the shit shields off

Griegboy, I see what you're saying. Valid argument. It's all about flow of air through the engine bay. As long as somehow you're achieving that when driving, then you'll be losing a lot of heat.

The bonnet and its fitting is integral to the safety design of the 'crumple zone' in an accident. To lift the hinges to allow air to escape pises real danger of a heavy sheet of metal being projected throught the front windscreen at head or neck height. Even removing the seal may have an adverse effect on impact.
In a serious accident it would no doubt be used to invalidate any insurance you may have.

Posted by: Bootsie

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The bonnet and its fitting is integral to the safety design of the 'crumple zone' in an accident. To lift the hinges to allow air to escape poses real danger of a heavy sheet of metal being projected throught the front windscreen at head or neck height. Even removing the seal may have an adverse effect on impact.
In a serious accident it would no doubt be used to invalidate any insurance you may have.

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Some one I trust told me that. Hence why I didn't do mine. Honestly after second scooping - on my list to do - I think the best cooling effort is a whopping great intercooler.

will fitting a thicker rad or a thermostat that lets the water through at a cooler temp (about 78oC from milners?) be a better option or not?

Some years ago a mate of mine in his Mini-Metro was travelling at around 60 mph on an A road when his bonnet flew up cracking his windsceen and causing him to stain his pants !! He managed to drive the car home looking out the side window and initially when it happened looking through the small bonnet vents they luckily had

did a very similar donkey job many years ago, e type, bonnet opens forwards, forgot to shut the catches, we off, apply brakes, bonnet moves up, oh fook, throttle pressed bonnet settles back, slow down very slowly, the bonnets up, no view forwards, wallets thinking it hopes im rich cos this could be expensive, got it to 20mph before slamming on, the bonnet by then had a mind of its own anyway and was fully committed to doing a suicide flip, lovely heavy chromed bumper over riders saved the bonnet, but me bezzy chrome

Posted by: TwedL200

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will fitting a thicker rad or a thermostat that lets the water through at a cooler temp (about 78oC from milners?) be a better option or not?

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I put the cooler 78 degree thermostat in mine when I was doing the EGR cooler bypass, can't do any harm
A bigger front mounted intercooler would make a big difference, I did toy with the idea of fitting a second standard intercooler under the second scoop, but it never got further than the inside of my head so I don't know it would be able to be grafted in.

I worked at a citroen main dealer for a few years and the Xantia's were bad for the bonnets flying open and skelping the roof, bad design with twin catches that didn't always engage

I love threads like this lots of different ideas, and food for thought

With you all the way Greigboy, I love ingenuity! I think I'd like to do the stat change. Your twin intercooler idea has got legs. For those who don't want to mess about with fitting a front mount.

GB - the second IC under the 2nd scoop won`t fit - tried it

speaking of second scoops....... remember this?



now theres this....



and with the manual leccy fan - the heat pours out of the engine bay ( I`m watching to see if any oil comes with the air flow up the windscreen)

Basil

Good work Bas. i take it it wasn't a pig to turn around? You could of course get scientific about this and fit a temp gauge under your bonnet and if you REALLY wanted to get accurate with it, a EGT sensor and gauge too. Run for a week and monitor and record temps with sccoop reversed. Then do the same with sccoop forwards. I'd be fascinated to see the recordings.

the bolts are arranged in a perfect square, but the tail of the scoop is longer than the snout, so it doesn`t bear close inspection for a dress vehicle - for a work vehicle (or test bed as its become) its fine - when stationary, with the leccy fan on the heat comes out much more than with the scoop facing forwards

Well that's a good start at least then

Basil the test pilot strikes again

Whilst I'm not allowed to drive (doctors orders) I'm finally going to get around to fitting these.
Bonnet vents
Nickburt done before and after tests and their was a definate drop in temperature with vents fitted on the bonnet to let the air escape.
What have we got to lose

Will throw up some pictures when they are on, hopefully by tonight.

Swanny

only thing im not keen on is the aesthetics side of them, if your keeping the truck then yes but i can see whats basically alli checkerplate being quite of putting to some

im supprised no ones thought of using a fan to drive the air out of the engine bay via these second vents, end the day if your in low you wont get much `sucked` out

after going through the water splash at `ness - switched the leccy fan back on and the steam poured oot of the second snout, evacuation is the way forward

A simple but effective solution to overheating.

theres an interesting chicken and egg scenario here, as first mooted I believe by the wee green fella - and its not a question -

overheating = burst head ....no overheating = no head trouble

except that its internal overheating that kills the 4D56, whilst there is a perceived design fault in the narrow spaces between valves means there is only a wee piece of head gasket material to fail - it is also true to say the tiny cracks that appear in the valve seats must contribute to the initial failure of the head - so if we can reduce head temperatures it must assist in reducing the appearance of these cracks and hence reduce the incidence of head failure, am i correct, obi-wan?

its difficult to say really, if you reduce the temperature too much the engine wont run properly and can cause premature wear of other components that are designed to run at a certain temperature. Venting hot air will assist and not interfere with the actual engine temperature. The intercooler does appear to be in a strange place on top of a hot engine, they have moved it to the front on the new shapes and it does seem more logical to make it work more efficiently.Wouldn't like to comment on the cracks in the valve seats I dont see engine temperature as the only thing that would cause that.

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Firstly I wana say that I like those bonnet vents.Take pics and lets us know how you get on Swanman, Where did you get them from?)

About the over heating issue I think both techniques will work. Allowing radiated heat to vent can only help. But it is unlikely to help more than internal cooling. I'm going to get scientific on this one and the next 'mod' I am going to fit is a EGT gauge like Werbung: this one.. All subsequent mods will then be able to monitor what happens to the EGt's and give some actual factual (I can ryhme! ) data rather than all this guess work we're doing. The first mod will be the front mount intercooler and the next is looking quite likely to be water injection. Could be the answer to all our questions and might well solve that initial problem. At the end of the day a head or gasket shouldn't just blow even if they have an inherent design flaw. I think internal temps are the answer. Like any good scientist (ahem) I just have to prove it.