mx5cartalk.com

Hi folks,

My '92 MX-5 has aftermarket headers with no heat shield. I'm wanting to get a shield to bring down bay temperatures and the Track Dog Racing one looks to be the best but shipping from over there costs more than the shield.

Does anybody know of a local alternative? I don't want to wrap the headers as it's daily dríven so I'd be worried about moisture getting trapped.

If you know anyone going to the USA, the postage within the USA is cheap.

The funniest thing is like many USA companies, the box they ship it in is the same size as the blanket laying out flat and the blanket is no more then 10mm thick, but the box is 20cm deep with this blanket lying in the bottom. Not the cheapest way to freight.
It is a very good heat shield IMO.

I'd just trim up an OEM heatshield to fit.

Otherwise go an buy some heat shield material and make one, ACL make (or used to at least?) a bendable sheet that you just cut and bent to shape.

Final option, just a regular sheet of steel and back it with some heatproof material (fibreglass or whatever)

tails wrote:don't want to wrap the headers as it's daily dríven so I'd be worried about moisture getting trapped.

You're saying that your headers won't produce enough heat to evaporate moisture on a daily basis but on the same token you're concerned about engine bay temperatures??

If the steam can't escape after being vaped there'd surely be some residual moisture left over after a drive though right? The heat would speed up the corrosion process.

I'm just guessing though.

I recall reading a while back (fair while, so might not be remembering 100% accurately) that heat wrap does increase the rate which the metal fatigues and/or rusts

It's a combination of moisture, and heat.
As the wrap insulates the pipes the metal heats us to a far greater degree than without, the years of superheat/cool cycling cna fatigue it and help cracks form.
the moisture is supposedly more an issue when not running, as the wrap holds it in not allowing it to evaporate.

regular heat shields don't hold moisture, and as they have an air gap they allow the pipes to run cooler (relatively speaking, they're still farking hot)

as I said, been ages since I read it so might have the details wrong, but that was supposedly the basic theory.
Note it was alos from the internet, so take from that what you will.




Personally i'd avoid the wraps purely because the stuff is a prick to work with and you'll be itching for the next week afterwards.

+1 for ACL - a number of forumites have made quality heat shields using ACL - not sure if pics still exist but if so: search.php?st=0&sk=t&sd=d&sr=posts&keywords=acl+heat

Hi.
They are easy to make but ensure you don't have the leading edge facing directly to the front as the air only "sees" the edge and goes around the plate. You should angle it towards the engine letting the air to hit the surface of the plate.