Mitegating in-cab heat - ideas?

[Johnnyb]

So my EB roasts people out, especially on warm days. Right now I am running bare floorboards and tunnel. I think the heat is transferring from the headers, which are ceramic and I don't really want to wrap them. Firewall is insulated but I still have some holes to plug.

Once the holes are plugged, I was thinking of getting WH rubber mat (full front: https://www.wildhorses4x4.com/early...BwE&gbraid=0AAAAAD8cIr8vx6Eu2h9s_8k_NoDpRfX4U) and gluing thermal pad to the back of it? Bummer is, I have to cut holes for the twin-stick and NP435.

Seem like a plan?

THX,
-JB

 

[tasker]

still have driver's cowl vent? makes a big difference (at least your side!)

 

[sk1nw4lk3r]

Sticky heat shield to the underside of the floors. Clean the underside nice, then cut and stick it on. Comesi n black also so it's not glaringly obvious. Made a WORLD of difference on my wife's 69 with bare floors.

 

[Johnnyb]

Sticky heat shield to the underside of the floors. Clean the underside nice, then cut and stick it on. Comesi n black also so it's not glaringly obvious. Made a WORLD of difference on my wife's 69 with bare floors.

I wonder about water retention when gluing stuff like that to the underside of the floors? I don't want to encourage rust.

 

[lars]

Better yet, aluminum heat shields on standoffs. I like 1100, basically pure aluminum. No strength but it doesn't need it, it's easy to form and it won't fatigue crack. I can get photos if you want.

 

[sk1nw4lk3r]

I wonder about water retention when gluing stuff like that to the underside of the floors? I don't want to encourage rust.

Totally reasonable thought process, I had the same.

We don't Ford rivers in her truck, it seldom sees rain, unless by true accident, and I feel like it seals tight enough against the underside to make it very difficult for the water to get to it.

It's not a perfect solution by any means, but it has certainly helped the problem I needed to address.

 

[ba123]

Better yet, aluminum heat shields on standoffs. I like 1100, basically pure aluminum. No strength but it doesn't need it, it's easy to form and it won't fatigue crack. I can get photos if you want.

+1

You don't need to wrap the headers to direct the heat in the right direction.

Get a pack of these things:

https://www.amazon.com/dp/B08D6Q1ZDV/?tag=classicbroncos-20

Get a sheet of aluminum heat reflector, like this (click here)

You can use stainless tie straps or hose clamps that attach these to your header and you screw the sheet there and it holds it away from the headers and will reflect heat away.

Hope that makes sense but if not, I could try to draw it out.

 

[ntsqd]

Heat shielding need not be attached to the exhaust. In OEM situations it rarely is. Look under any late model truck (Tacoma is a good choice) to see how they do it. An air gap between the shield and the floor is needed. Better if you can encourage some air flow between them.

Wrapping un-coated mild steel exhaust is a bad idea. The extra contained heat will rust it out much, much faster.

 

[sk1nw4lk3r]

+1

You don't need to wrap the headers to direct the heat in the right direction.

Get a pack of these things:

http://[URL]https://www.amazon.com/dp/B08D6Q1ZDV/?tag=classicbroncos-20

[/URL]

Get a sheet of aluminum heat reflector, like this (click here)

You can use stainless tie straps or hose clamps that attach these to your header and you screw the sheet there and it holds it away from the headers and will reflect heat away.

Hope that makes sense but if not, I could try to draw it out.

This is a great solution as well.

 

[Johnnyb]

+1

You don't need to wrap the headers to direct the heat in the right direction.

Get a pack of these things:

http://[URL]https://www.amazon.com/dp/B08D6Q1ZDV/?tag=classicbroncos-20

[/URL]

Get a sheet of aluminum heat reflector, like this (click here)

You can use stainless tie straps or hose clamps that attach these to your header and you screw the sheet there and it holds it away from the headers and will reflect heat away.

Hope that makes sense but if not, I could try to draw it out.

Those look really interesting but I'm having trouble picturing it in my mind. It looks like the gates clamps hold the brackets to the header and the bolt holds the heat shield to the clamp? Is there enough room for effective heat deflection?

Thanks,
JB

 

[ba123]

Those look really interesting but I'm having trouble picturing it in my mind. It looks like the gates clamps hold the brackets to the header and the bolt holds the heat shield to the clamp? Is there enough room for effective heat deflection?

Thanks,
JB

Correct and yes, it is far enough away as that’s what they are made for.

Here’s a pic of the underside before mounting:

Here’s another brand that gives a larger gap but I don’t think it’s necessary (click here):

 

[fordguy]

I used lizard skin (both sound and insulating) on inside and underneath. Then put the sound mat on front floor boards. works ok here in the hot south.

 

[Johnnyb]

Correct and yes, it is far enough away as that’s what they are made for.

Here’s a pic of the underside before mounting:
View attachment 967905

Here’s another brand that gives a larger gap but I don’t think it’s necessary (click here):
View attachment 967917

Thanks for the details!

 

[lars]

I took the below arguably crappy photos today, while groveling under my Bronco to install a catalytic converter. Which is amazing but a topic for a different thread. What's visible is a greasy piece of 1/16" pure aluminum (no fancy alloys) sheet on 1-1/4" long threaded hex standoffs. 1/4-20 thread all the way through. This was stupid easy to make and install, and the difference was transformative.

I mostly use my Bronco for back country travel, loaded with gear. I had the entire interior sprayed with LineX 25 years ago. Experimented with various interior mats and eventually settled on rubber everywhere, from some long forgotten source, with some dense insulation underneath. Exhaust was and still is a 2 into 1 system down the right side. At some point I discovered that the LineX on the tunnel down the right side had lifted off the metal floor because it got so hot. And traveling with boxes of gear in the back I happened to be thinking about how warm it was inside (I run a hard top year round) despite being around freezing where I was traveling. Reached down and shifted a cargo box out of the way behind the passenger seat, touched the floor mat. It was too hot to touch. When I got home and was cleaning up I pulled the mat and insulation away, discovered that the LineX there had been scorched off as well. That's when I decided to try the heat shield, based on what I'd seen under new cars. I have driven countless trips since then with stuff in the back, this time with a thermocouple connected to my multimeter. Floor behind the seats never gets hotter than about 120°. When I did the 408 swap a few years ago I added more heat shields on standoffs to the right side of the tunnel. What a difference.

As far as I'm concerned based on my experiences, fixed heat shields are the gold standard for managing interior heat. Not that you shouldn't also take other measures, but start there. If you can cut sheet metal, use a hammer (to bend flanges etc) and drill holes, you have all the fab skills you need to make them.

I should add that all the holes I drilled through the floor l sealed with RTV to keep water out. The rear heat shield has been on for at least 15 years and there is no sign of water intrusion (and I've given water plenty of chances).

 

[toddz69]

Excellent work, as always....and I see another excellent use for that shield - an excellent grease catcher for the CV that inevitably makes a nice coating of grease on the underside of our rigs for whomever greases their driveshaft as they should.....

Todd Z.

 

[ntsqd]

Seeing those pics reminded me of something that I read a long time ago. The heat radiated off of, and reflected by pavement can be exceptional. A surprising amount of the under-body heat is from the pavement. Large heat shields like those will do more than just shield from localized sources like the exhaust.

Not long ago there was a thread here where these thermal insulating micro-spheres were mentioned. A good idea might be to include them in the under-body paint. As a bonus I noticed in reading that page that noise is also attenuated by including them. Who wouldn't want more heat and noise insulation for the cost of a coat of paint?

 

[Revelation]

My last Bronco had a 2 inch body lift, and had no issues with heat in the cab, no A/C, Floorboards got warm at the most on 3-4 hour trips

 

[lars]

My last Bronco had a 2 inch body lift, and had no issues with heat in the cab, no A/C, Floorboards got warm at the most on 3-4 hour trips

Are you suggesting that a 2 inch body lift and no A/C will take care of floorboard heat?

 

[nvrstuk]

Well, with a 2" + body lift for 20+ yrs and having taken floor and tunnel temps to record how FREAKIN' hot the floors got and they were 140-150+ deg F I did the alum floor and firewall shielding when I had my rig all torn apart 8yrs ago. Now in 100+ deg temps and after cruising steadily at over 50mph for an hour my floor temps (also recorded here on CB) were barely 12-15 deg F warmer than the ambient temp outside. I consider that as a phenomenal improvement since my 600hp engine probably puts out twice the BTU's as most Bronco engines do. Just saying that w/o a heat deflection shield you will NOT get much noticeable improvement because I tried back around 1988 or so with thermal backed chimney insulation. Alum backed stuff that was supposed to be approved for mounting chimneys closer to combusibles... anyway, it was glued on with vertical or front to back lines of whatever the mastic was so rain/water would have a way to run out and not collect because there is NO WAY you will seal up all the edges to prevent rust from forming.

I had to scrap this stuff off in 2016 as it was still stuck on the floor and firewall well but didn't really do anything.

Do what Lars and all of us have done- aluminum sheets that are spaced 1/2" away from the floor so air can move between them- that is the key. My fire marshall friend turned me on to this back in the early '80's.

 

[nvrstuk]

Are you suggesting that a 2 inch body lift and no A/C will take care of floorboard heat?

All you need to do to prove this theory wrong is to stand 2" away from a woodstove! (bet he doesn't last 30 sec.). Even with a fan blowing you will blister.

Then try this with a pc of alum or sheet metal that is only 1/2" from your body but still standing 2" from the woodstove... you won't feel a thing.... fan or no fan.

We did this in my shop (when we were living in it FT) before we built the house. Nothing like feeling is believing!