20 Valve Black Top Heat Shield

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20 Valve Black Top Heat Shield

Postby BZ Touring » Mon Feb 12, 2007 11:35 am

Managed to sheer off a couple of the bolts that hold on the heat shield that covers the factory exhaust extractors in the engine bay :roll: (black top 20 valve)

Before I go to the trouble of drilling the bolt ends out, I was wondering how essential that heat shield is, particularly given that the extractors aren't completely covered or isolated from the engine bay even with the shield in place.

Also, if some sort of shielding is necessary, would I be better off wrapping the extractors?

Cheers.
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Postby Flunk » Mon Feb 12, 2007 11:45 am

I don't know if you would call it "major" but being so close to the radiator, I think it does help somewhat, I took mine off to experiment, and noticed about a 20 degree increase in overall water temp, and slight increase in oil temp, for some reason, put it back, and the temps went back down... ( I'm one of these overkill guage people, have oil temp & pres. water temp, volts, boost etc. )
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Postby BZ Touring » Mon Feb 12, 2007 11:55 am

Interesting observations, thanks. It is strange though that the heat shield doesn't actually "shield" the radiator from the extractors. I'm not actually sure what it's shielding. May be just heat rising up through the extractors and into the engine bay, but even then it seems fairly small to do an effective job.
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Postby aesc » Mon Feb 12, 2007 12:36 pm

I doubt you'd have a 20 degree increase in water temp just by removing the heat shield. So what your saying Flunk is that your water temp after was 100-105 degrees? Doesnt sound right

The heat shield is there for a reason, use it. Especially if you have a pod filter setup with no cold air induction it will hurt performance
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Postby Flunk » Mon Feb 12, 2007 1:17 pm

aesc wrote:I doubt you'd have a 20 degree increase in water temp just by removing the heat shield. So what your saying Flunk is that your water temp after was 100-105 degrees? Doesnt sound right

The heat shield is there for a reason, use it. Especially if you have a pod filter setup with no cold air induction it will hurt performance


negative. My usual running water temp is around 60-65deg. was closer to 85 with heat shield off, replaced, back down to 60'sh, im guessing it was the heat shield, could have been something else. call it what you will.
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Postby aesc » Mon Feb 12, 2007 1:24 pm

Thats really strange ay. Normal operating temp it should be around 80-85 anyway, wouldve thought 60 is way too low. I'd be looking to replace the thermostat
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Postby sergei » Mon Feb 12, 2007 1:58 pm

Flunk wrote:
aesc wrote:I doubt you'd have a 20 degree increase in water temp just by removing the heat shield. So what your saying Flunk is that your water temp after was 100-105 degrees? Doesnt sound right

The heat shield is there for a reason, use it. Especially if you have a pod filter setup with no cold air induction it will hurt performance


negative. My usual running water temp is around 60-65deg. was closer to 85 with heat shield off, replaced, back down to 60'sh, im guessing it was the heat shield, could have been something else. call it what you will.


I think you either measuring at radiator or have bunged thermostat...
Anyway 20v don't produce a lot of heat in the extractor area, in fact on my 20v after good drive I could touch the manifold with hand without getting burned - it has only 1 layer of regular glass fiber wrap on it.
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Postby matt dunn » Mon Feb 12, 2007 7:35 pm

sergei wrote:
I think you either measuring at radiator or have bunged thermostat...


I agree, if your car is not running at the temperature that is stated on the thermostat +/- 5, which will be 82 degrees +/-5, then there is something wrong with the car or the gauge.

You do know that for a gauge to be accurate it must be on the engine side of the thermostat?
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Postby L0rolla1 » Thu May 31, 2007 8:11 pm

how bout the wrap stuff that u can buy. would it be a good thinng to do as i have also removed the 'heat sheild' and cleaned up the extractors.

and how far along the exhaust would u recond i wrap, the more the better or what?
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Postby Calvin » Thu May 31, 2007 11:09 pm

some of the heat shields ive seen only cover the very top of the manifold.. what is the point in that.. ill try find an example but some of you will know what i mean.

EDIT:
Image

Is like that on all 20v's.. Not exactly shielding the radiator eh..
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Postby Bling » Thu May 31, 2007 11:26 pm

Probably to stop people getting easy access to a burnt hand.

Or to deflect some of the extractor heat away from the bonnet.
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Postby Calvin » Thu May 31, 2007 11:28 pm

BZG|Bling wrote:Probably to stop people getting easy access to a burnt hand.

Or to deflect some of the extractor heat away from the bonnet.


Nothing to do with the radiator though.. so i dont see how this can affect temps taken at the thermostat

And the heat shield still going to be mighty hot.. But i suppose it may act as a heatsink type thing?
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Postby L0rolla1 » Fri Jun 01, 2007 11:24 pm

so ive taken that shity piece'a metal off and grinded off the mounting bolts on the extractor for it. now im going to get that heat wrap stuff. my q. is how far along the exhaust should u wrap??? do i do jus the extractors themselves or keep going down the exhaust :?:
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