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Tips on how to fabricate a mica heat shield for the LIM?

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Old Jun 29, 2023 | 03:38 PM
  #26  
dk_davis's Avatar
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From: near Deals Gap

Another product that may be worth considering is "Teknofibra Thermal Direct Contact Heat Shield Kit". It is a flexible sheet and I noticed 2 and 4 mm thicknesses. The parent company is in Milan Italy and may be called TECNAUTO so it may be more accessible for European owners. Searching from the above phrase returns many results for suppliers in the US. EPARTRADE also lists a supplier.

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Old Jul 4, 2023 | 07:22 PM
  #27  
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This is a continuation of post #22. I finished up my lim shield with “heatshield products inferno ” . It’s a bit more rigid than the original alum version I was using and quite a bit thinner. I think it being a bit more sturdy will hold up better than the softer alum which got a bit ratty looking after a couple years ( every time you touched it would distort some making it hard to bend back straight) . I purchased sku #120620 which is 304 ss 14”x 20”. I would have preferred to use the smaller 6” x 14” because it was noticeably less expensive but it did not have the coverage I was looking for. It encompasses the whole lim, wrapping around the bottom and both sides. I’m happy with the coverage and temperature rating ( 1800° continuous / 2200° intermittent). The only negative is I won’t be able to see my nicely coated xcessive lim. I modeled it after Alex’s shield height in the above posts. Should be an improvement over my old shield since it’s a bit taller and higher heat rating.

~ GW















Old Aug 8, 2025 | 03:08 PM
  #28  
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After procrastinating for over 2 years, I finally got around to building myself a mica heat shield for my FD. I used the flexible mica material sold by McMaster-Carr, in 0.032 thick, 23 x 39 inch sheets. I made my shield from a 4 layer laminate of the mica, riveted to a 1/16" thick AL sheet frame. The mica is flexible, but will hold it's shape when bent/formed, much like a thin gauge sheet metal. The whole affair bolts up to 2 of the UIM studs, and a M6 bolt that threads into an unused threaded hole on the LIM's front runner. For reference, I'm running a Cosmo LIM & UIM, and the turbo install puts the turbine really close to the front LIM runner. Pictures will explain better than I can...

Heres a shot of my turbo AFTER removing the turbo blanket - with the blanket installed, it already brushes against the LIM front runner, leaving no real space for shielding
Here's a shot of my turbo AFTER removing the turbo blanket - with the blanket installed, it already brushes against the LIM front runner, leaving no real space for shielding


Heres a tip view of the AL frame fabricated to hold the mica sheets in position
Here's a tip view of the AL frame fabricated to hold the mica sheets in position
And heres a side view of the frame, before trimming off the excess AL (see sharpie marks) that got in the way during the mock-up stage
And here's a side view of the frame, before trimming off the excess AL (see sharpie marks) that got in the way during the mock-up stage
Heres a mock-up shot - just the frame installed
Here's an initial mock-up shot - just the frame installed. After this, I bent the corner a few more degrees inward to follow the LIM/UIM runner more closely.


And heres another mock-up shot - AFTER bending the frame in more, and with one sheet of mica for testing. That front edge of mica was then bent around the contour of the LIM front runner, and I marked it for where the M6 hole needed to be punched thru to allow me to bolt that edge to the LIM
And here's another mock-up shot - AFTER bending the frame in more, and with one sheet of mica for testing. That front edge of mica was then bent around the contour of the LIM front runner, and I marked it for where the M6 hole needed to be punched thru to allow me to bolt that edge to the LIM


And heres the finished mica shield assembly with the 4 layers of mica sheet all bolted up.
And here's the finished mica shield assembly with the 4 layers of mica sheet all bolted up.
Close up of the tight front edge - getting that turbo blanket back on will take some persuasion, and it WILL contact the mica shield. Which should be OK since the mica is rated for 1832*F contact temp.
Close up of the tight front edge - getting that turbo blanket back on will take some persuasion, and it WILL contact the mica shield. Which should be OK since the mica is rated for 1832*F contact temp.
Almost done - PTP Turbo
Almost done - PTP Turbo "lava" blanket re-installed.
And DONE - strut bar back where it belongs
And DONE - strut bar back where it belongs

So after finishing it up I went for a test drive - the mica held up just fine with no weird smells or anything of that sort from the heat contact with the turbo blanket. But I did smell burning oil - I got a tiny leak on the turbo oil feed line at the turbo, as I must have buggered up that connection while wrestling the turbo blanket back on. So that line needs to be re-done before putting the car on the road again.
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Old Aug 8, 2025 | 03:19 PM
  #29  
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From: Stafford, Ks.
Looks good Pete. That shielded air gap should help substantially with intake temps.
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Old Aug 9, 2025 | 09:33 AM
  #30  
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From: Florence, Alabama
very nice.

a heat shield that actually uses a material that actually shields heat

mica .7 (that's point seven)
inconel 15
stainless steel 14

fiberglass is in the same category as mica but the resin melts around 1000 F.

it would have been better if you made your backing plate from stainless steel as aluminum is 237.

is your air filter out of the IC exhaust?

a sano engine bay

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Old Aug 9, 2025 | 09:48 AM
  #31  
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From: AZ
Originally Posted by Howard Coleman
mica .7 (that's point seven)
inconel 15
stainless steel 14

fiberglass is in the same category as mica but the resin melts around 1000 F.
This is what I think people get confused. The "Inconel" heat sheilds that most people use do not use the inconel for heat shielding. It's really a fiberglass heat shield. The inconel just protects the fiberglass. These shields, or at least the ones I use, have a core of fiberglass inside of them.

Last edited by Neutron; Aug 9, 2025 at 01:54 PM.
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Old Aug 9, 2025 | 11:51 AM
  #32  
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From: Elkton, MD
Originally Posted by Howard Coleman
it would have been better if you made your backing plate from stainless steel as aluminum is 237.

is your air filter out of the IC exhaust?

a sano engine bay
I thought about using SS, but I already had plenty of 1/16" thick 6061 AL already laying around the shop, so one less expense and no waiting on shipping. It's not shown in my post, but I cut out much of the AL structure from the mock-up piece before I went final by riveting the mica layers to the frame - I basically just have AL behind the mica along the top edge and wherever the mica layers are riveted to it. Choice of AL vs SS probably won't matter too much in this design, since the AL is buried under 3 layers of mica on the outer/turbo hot side, and one layer on the cooler LIM side.

Air filter is completely sealed from engine bay heat within a sheet metal enclosure, which gets its fresh air via a duct to the front of the radiator. I used the space between the frame rail and the side of the radiator for the ducting. Next project is to see if I can figure out a way to enclose a larger filter than what I have now, which is a bit on the puny side.
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Old Aug 11, 2025 | 10:07 AM
  #33  
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Here's mine:


I like to harvest exhaust shields from OE applications and cut/repurpose them. I slapped some gold foil on this for bling, in my testing it didn't really do much. I drilled and tapped a few spots on the ACV port casting on the LIM to mount the shield.
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