Dealing with engine heat in a flat fender

brengl1942

Well-Known Member
Joined
May 13, 2015
Location
Hurdle Mills
I'm curious how folks are managing heat in small vehicles like a Willys or with buggies? I have just a Ford 2.3 with the stock ford manifold in my flat fender, and after a while of driving the footwell area and trans tunnel gets uncomfortably hot from both exhaust heat and the hot air getting blown back by my SPAL fan up front. After a while of driving it feels like there are hair dryers blowing on your legs. Even the shift levers get warm to the touch. I suppose the main issue is that there is nothing there but a sheet of 16ga sheet metal separating us from the engine bay, but that's the case with any old Willys, CJ, and a lot of custom built buggies and whatnot.
Anyone experience this problem and find a solution? One thing I'm considering is some sort of heat shielding for the manfiold and exhaust pipe, but I'm not sure how much it will help in terms of keeping the firewall and footwell from getting hot.
 
You can find a lot of different adhesive insulators these days. They come in rolls and are generally foil lined on the outside. You could cover the firewall and tub with that stuff in conjuction with some exhaust wrap. Just a thought.
 
If you have the space, you can add a heat deflector under/on the engine side of the firewall/floor. A cheap way is to use airbake pans. Could just be a piece of metal, with an air gap to the floor/firewall.

Otherwise, as said there are a number of stick-on insulators or spray on coatings that will help. If heat is coming from the exhaust, some wrap it to help with that.
 
Yeah, my worry with wraps or adhesive materials is rust over time. I'm leaning towards trying to fabricate some sort of heat deflector setup for the manifold and "downpipe" section of the exhaust. Your idea about a deflector on the firewall itself is good as well, I'll have to think about that. I have the factory Ford ICRM (relay module) mounted on the firewall behind the exhaust side as well, and I'm also a bit concerned about how hot it is getting. I may look at doing some sort of little metal box or shield for it as well. If that goes out I'm dead in the water.
I'm sure in the winter time all the heat will be welcome, no need for an actual heater :). But this time of year it's rough.
 
Croatan_Kid said:
You can find a lot of different adhesive insulators these days. They come in rolls and are generally foil lined on the outside. You could cover the firewall and tub with that stuff in conjuction with some exhaust wrap. Just a thought.
Click to expand...
This.

We use it in specific locations on the bottom of the cab floor directly over top of the exhaust pipe.

The paint on ceramic stuff didn't work.
 
Anyone here used DEI Tunnel Shield? I got a recommendation for that, supposedly it works well as an adhesive insulator.
 
It probably works just fine. I like that it's the hard almost aluminum pie plate type material. You could even use that in the tunnel as well as a layer of adhesive stuff to really kill noise and heat!

There's a bunch of stuff you can find on Amazon. I was looking at sound deadener for the cab and doors of my HD. Basically the same stuff as DynoMat, but half the price. A lot of sound deadeners reject heat and vice versa.

The key is, with anything, surface prep. Clean it real good like, use a heat gun to help mold it and kick off the adhesive, and a few plastic tools/rubber roller to get it really formed and stuck to the tub. If nothing can get behind it, it can't hold moisture and won't rust!

This is along the lines of what I was talking about. There's dozens of products though. No need to spend a crap load of money on it. Look around and read reviews. That's the best part about Amazon.

Amazon product ASIN B004PILLZG
 
You can wrap the exhaust or build a shield. I had to wrap a portion of the exhaust on my frontier because the heat was damaging the parking brake cable that I could not route any farther away. Eliminated the issue I had; I would assume it would help quite a bit.
 
So I have ended up buying a manifold/header kit from HeatShield Products to try first. You have to custom cut/fit it to the manifold and pipes. Hopefully it will greatly reduce the heat coming from the manifold under the hood. If that alone isn't enough I'll look at further measures.
It may be a while before I can try it though, I just had to pull the trans to deal with a leaking input shaft :(
 
brengl1942 said:
It may be a while before I can try it though, I just had to pull the trans to deal with a leaking input shaft :(
Click to expand...
Make sure to purchase a sealed front bearing and swap it out after you pull the seal facing the inside of the case. That will drastically reduce the chance of leaks.
 
OnlyOneDR said:
Make sure to purchase a sealed front bearing and swap it out after you pull the seal facing the inside of the case. That will drastically reduce the chance of leaks.
Click to expand...
Funny you mention that, I DO have a sealed bearing, nice new USA made SKS. This transmission is freshly rebuilt mostly with Novak parts. The only original parts left in it are the input shaft and case. I believe the problem is that the front bearing does not fit tightly into the case, not tight enough to seal, and there is also some wear on the input shaft causing it not to seal around the inner bearing race either. I believe the lube is leaking around both areas, and since I plugged the original drain hole (as per Novak instructions) the lube has nowhere to go but out.
My current plan is to unplug the drain hole and get an original felt washer, then button it all back up again. Hopefully the lube will drain back into the case as it would have with the original open bearing design. The only other option is tearing the whole thing down again and probably finding a new case with tighter tolerance for the input bearing hole. I'm hoping I can just stop this leak and run this one as-is, meanwhile I'll try to acquire a better T-90 to replace it when the slight play in the input shaft eventually wears out the internals prematurely.
 
@brengl1942 I've got a 48 willys with a 4.3. It hasn't been touched in a while....

Anyway Im planning on using the stick on heat deflector on the firewall and trans cover. I did wrap most of the exhaust as well. With the minimal run time I've had, the floor hasn't been too hot from the exhaust but you can feel it coming up through the trans tunnel(not installed yet).
 
YJJPWrangler said:
@brengl1942 I've got a 48 willys with a 4.3. It hasn't been touched in a while....

Anyway Im planning on using the stick on heat deflector on the firewall and trans cover. I did wrap most of the exhaust as well. With the minimal run time I've had, the floor hasn't been too hot from the exhaust but you can feel it coming up through the trans tunnel(not installed yet).
Click to expand...


I had to cut away some of my tunnel to get the T-98 installed. It feels like a blast oven coming through the hole now. Hopefully I can get a new tunnel pieced together this winter.
 
brengl1942 said:
I'm curious how folks are managing heat in small vehicles like a Willys or with buggies? I have just a Ford 2.3 with the stock ford manifold in my flat fender, and after a while of driving the footwell area and trans tunnel gets uncomfortably hot from both exhaust heat and the hot air getting blown back by my SPAL fan up front. After a while of driving it feels like there are hair dryers blowing on your legs. Even the shift levers get warm to the touch. I suppose the main issue is that there is nothing there but a sheet of 16ga sheet metal separating us from the engine bay, but that's the case with any old Willys, CJ, and a lot of custom built buggies and whatnot.
Anyone experience this problem and find a solution? One thing I'm considering is some sort of heat shielding for the manfiold and exhaust pipe, but I'm not sure how much it will help in terms of keeping the firewall and footwell from getting hot.
Click to expand...
No pics? WTF?
 
pics of what? :) At the moment I'm dealing with a worse problem involving the transmission input shaft and pilot bearing. I haven't made any progress with the heat issue.
If it satisfies your pic craving, here's one of the engine bay:
IMG_20210905_174258387~2.jpg
 
I posted some of the whole jeep last week in the "let's see those jeeps" photo thread.
nc4x4.com

let's see those JEEPS

No love from @CasterTroy and @jeepinmatt took it down 16 this morning. Guy in an A7 pulled up beside and started pacing me. I floored it and left him. He quickly caught up and passed while tapping the roof with his left hand I mean - I sure hope he could catch me right?!? I like it, just...
nc4x4.com nc4x4.com
nc4x4.com

let's see those JEEPS

No love from @CasterTroy and @jeepinmatt took it down 16 this morning. Guy in an A7 pulled up beside and started pacing me. I floored it and left him. He quickly caught up and passed while tapping the roof with his left hand I mean - I sure hope he could catch me right?!? I like it, just...
nc4x4.com nc4x4.com
 
I had a hiatus while waiting on this to get my jeep going again, took about 5 months to get a custom bell from Quicktime. Also had to partially rebuild the trans to install a new NOS input shaft and deal with a massive lube leak.

IMG_20220317_183532274.jpg


On the heat issue, I purchased a kit from Heat Shield Products and fashioned up a manifold shield and a deflector that to help protect the passenger side floor and trans tunnel. I also shaped it to help deflect heat from soaking into the ICRM (relay module) hanging out just above the exhaust :-0. Not the prettiest thing ever but has made a noticeable improvement. My only concern is how well the material will hold up if I get into mud/water. I don't think it will hurt it, but it may promote rust underneath if it holds moisture.

IMG_20220331_175544549.jpg
 
That looks like a good product for the floorpan perhaps, but is only rated for 350˚F so couldn't go on the manifold. My biggest issue was heat from the manifold blasting through the hole in the trans tunnel and heat soaking everything under the hood. The manifold itself already had a ceramic coating on the outside.
 
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