Exhaust Manifold Heat Shield REVIEW – AliExpress vs DEI
Exhaust heat shield. Aluminium sheet with dimpled finish.
This is a non scientific review of an exhaust manifold heat shield from AliExpress. I’ll assess it’s performance and then compare the cost and ease of installation to some mainstream products from DEI & Zircotec.
Exhaust Manifold Heat Shield from AliExpress
This is the exhaust manifold heat shield I’m using. It’s super cheap and should be hard wearing given that it’s a sheet of aluminium. The indentations on the sheet are pronounced which makes it easy to bend and should help the insulation properties because less of the material will be touching the exhaust.
The Engine
The engine I tested this heat shield on is a VAG 1.8T with a K04-064 turbo. This turbo uses an integrated cast iron manifold. The problem was opening the hood/bonnet after a blast would release a very strong wave of heat from the engine bay. It just felt like the engine bay should not be getting that hot. And in addition to this, the intake pipe ran over the turbo and this pipe would get so hot it was almost impossible to touch it.
The turbo manifold did not have any heat-shielding whatsoever so the plan was to add some and see what difference it made.
Heat Shield Placement
I used the Chinese heat shield in three places.
The first was over the exhaust manifold. I cut a rectangle piece big enough to bend over either side of the manifold slightly and enough to bend under the manifold at the back to give some sort of protection to the compressor. When it was bent to shape I cut out some slits in it to go around to lines feeding the turbo centre section.
The other piece was placed on hoses which ran close to the downpipe. The last piece was placed over the wastgate actuator because the actuator had no shielding.
Not to difficult to install. I used some card to make the templates. The manifold shield was secured with some screws which used some unused threaded holes in the cylinder head. The other two shields are held in place with metal ties.
The Result
Opening the hood after a good drive and the heat released from the engine bay was hardly noticeable. It felt like what I would expect from a factory engine.
The intake pipe only gets warm with the shield in place rather than almost too hot to touch.
I can’t comment on the effectiveness of the shields on the pipes and actuator but logically the temps must be less.
Was It Worth Doing?
Absolutely. I guess the shields only took an hour or so to fit and the difference, using my unscientific test was dramatic.
AliExpress Heat Shield vs DEI Form-a-Shield and DEI Heat Screen.
DEI make a huge range of heat shield products for different purposes. These are the ones I have experience of.
Heat Screen first.
Heat screen will do the same job as the Chinese shield I believe, although the peak temperatures the Heat Screen can handle is probably lower than bare aluminium metal. Installation of Heat Screen will probably be easier because it’s a fabric and because you don’t have to be so careful installing it because it does not have sharp edges like the metal sheet.
Those are the pluses but there are also negatives.
First is cost. The DEI is around three times the price of the Chinese sheet.
The second issue is longevity. In my experience the Heat Screen will harden and become brittle over time. Eventually it cracks and falls to pieces. Again my experience. I think this is probably down to using it on an exhaust manifold. The heat is too much for it. I don’t see any longevity issues with the Chinese ally sheet.
Form-A-Shield
The Form-a-Shield has a similar, possibly thicker aluminium sheet but it combines this with an insulation layer. DEI say it’s fine for turbos and manifolds. I’d say Form-A-Shield will do an even better job than the Chinese sheet with regards to insulation and I think it will last as long.
But there are some downsides with the Form-a-Shield.
Again, the cost. Around four times the cost of the AliExpress shield. I think fitting the Form-a-Shield is also going to be more difficult because it’s a thicker material all round. I have Form-a-Shield in stock but I decided to use the AliExpress shield for this reason. Space was a bit tight to get the Form-a-Shield on. It could be done but it was more work.
And the final possible downside of the Form-A-Shield is it’s insulating properties. Do we really need to keep so much heat in? Will that damage the turbo/manifold if so much heat is being kept in?
I am more than happy with the performance of the AliExpress heatshield, I’m not thinking I’d like any more insulation on the exhaust.
AliExpress Chinese Exhaust Heat Shield – Summary
I think you get the idea by now. I think it’s a definite win from all aspects ie price, formability, longetivity and insulation performance. Perhaps there are some mega heat problems in an engine bay somewhere where double layered shielding is needed but I can’t imagine how bad it would have to be for the Chinese shield not to be enough. And if worse can to the worse, you could always use two layers of it.
In short, the Chinese aluminium heat shield is a win and gets a StrikeEngine recommended.
Other Products
Some notable mentions
DEI
DEI have a similar (possibly identical) product to the Chinese shield. They call it “Dimpled Aluminium”. This comes in bigger pieces than the Chinese version but I’m not sure that’s important. I had to cut down the 30cm x 50cm sheet to cover the manifold. And the price of the DEI product also looks to be around twice the price.
Zircotec
There are exhaust manifold coatings out there. Zircotec springs to mind. I don’t have personal experience of the coatings but speaking to people that have, they say it’s almost miraculous. It probably looks nicer than a heatshield and takes up less space. But the difference in cost is huge.
Zircoflex Foil is one I do have experience of. Super easy to work with, almost like kitchen foil but tougher with ceramic squares on one side. Again, does as good a job as the Chinese shield with the benefit of being much easier to fit. But the downside is the cost which is multiples higher than the Chinese shield but no doubt, the Zircotec looks more professional.
