Making and exhaust manifold heat shield

[cantfindausername]

Hi all,

I need to make a heat shield for my exhaust manifold and I'm after some advice on material and design.

This is my manifold...





There are a few studs spare on the head which I intend to use to mount the heatshield. And my initial idea is to just come up and over the runners with a bit of coverage down the side. Does that sound adequate?

Many thanks,
Ant

[ASF72]

Hi Ant,

Nice manifold, can i ask where you had it made.

Regards

Nino

[cantfindausername]

Some guy in canada that a friend put me in touch with.

[Testament]

Stainless steel sheet cut and bent up to suit would work, or you can get purpose made heat sheild material, usually some kind of thin steel sheets with little "cells" pressed into it to hold air and reduce heat transfer and with some kind of aluminised type coating.

Design really depends on the installation in the car and how much room there is, where the air may be flowing in the engine bay, what other components are nearby - remember that the sheilding doesnt "stop" the heat, it reflects it and contains it to some degree so it will probably cause higher temperatures in some areas at the same time as reducing them in others.

[cantfindausername]

Thanks for the info. I think the design I will try to incorporate is to sort of "cup" the top of the manifold so it keeps more of the heat in there.

[manoa matt]

A heat shield will help shield surrounding elements from the heat of the manifold, but the under hood temperature will still stay the same. Why not ceramic coat it? The ceramic coating will keep the heat inside the manifold, negating the need for a heat shield. It should also reduce your under hood temps, which is good.

[cantfindausername]

The fans do a good job of pulling the heat out of the engine bay. Its the melting of the fan surround that is starting to concern me, so its the direct heat that I need to address.

Ceramic coating on something like this would be too pricey I think.

[TR-Spider]

You need to protect the plasic from the radiation.
You can buy sheets of thin double layer aluminium, which you can still bend.
You can buy that at race shops.
Try to mount it between the exhaust and the endangered plasic parts, but try to leave passages for some air flow.
Some pictures of your engine bay could help...

Thomas

[cantfindausername]

Here are a few pics of the engine bay...

[TR-Spider]

Ah, now I see...
That looks nice, with lots of proper executed work.

However the engine bay is really tight and the header quite close to the lid.
Judjing fron the headers colour it is close to glowing dark red during operation.
Probably the best to place the cover as a box, closed towards front, sides and top, but open towards the back to let the heat escape.
Where is the freh air coming from, from the side vents in the body?
I would be concerned about the intake temperature (despite intercooler after the turbo), did you measure it?

The fans remind me on that Chapparal (?) racecar of the early 70s who had these big fans for downforce...

Thomas

[cantfindausername]

Ah, now I see...
That looks nice, with lots of proper executed work.

However the engine bay is really tight and the header quite close to the lid.
Judjing fron the headers colour it is close to glowing dark red during operation.
Probably the best to place the cover as a box, closed towards front, sides and top, but open towards the back to let the heat escape.
Where is the freh air coming from, from the side vents in the body?
I would be concerned about the intake temperature (despite intercooler after the turbo), did you measure it?

The fans remind me on that Chapparal (?) racecar of the early 70s who had these big fans for downforce...

Thomas

yes the manifold is quite close to the lid, but its closer still to the first bit of the I/C pipework.

I've never had any issues (as far as I'm aware) with intake temps. Certainly nothing has been mentioned by Phill when he's checked the logs.

You mention boxing the manifold in. This is the idea that I had to try and keep as much heat "in" as possible.

The fresh air is coming from under the car mainly. The drivers side intake is blocked off to direct air into the boot for the I/C, and the passenger side vent is open, supplying the Intake and engine bay with cool air.

Just had a google for the Chaparral race car. Its the 2J that has the fans.... looks mental!