Heatwrapping to prevent thermal soak

So after being a jeep I-6 owner for 7 years, I more than realize the huge disadvantage of the exhaust manifold under the intake. (Still not sure why anyone would think that was a smart thing to do) when I installed the rebuilt engine 3 years ago, I cool taped the intake runners, and the heat sheilds in hope it would help. but still got insanely hot. So I used the vht paint and baked it, then dei heat wrapped a new dorman manifold. In hope it will help my under hood temps. I will also heatwrap the exhaust right until the cat. Any other tips one may try??
I'm well aware of others bad experiences with cracking, moisture, corrosion etc, and I dont really need any input on those issues.



dont mind the messy red green shop haha

Be carefully with the wrap. It can hold moisture and make the manifold rust fast and you won't know it befor it's to late. Stuff works great, just something to keep an eye on.

looks good let us know how well it works.

You have to remember how old the AMC 4.0L is. The engine design that brings the exhaust out the same side as the intake is old as dirt. It had it's advantages in the carburetor days because you could pre-heat the air/fuel charge in cold weather to the advantage of getting a better mixture and better cold running characteristics. However, when hot, the design was given to heat soak issues (Even with carbs), and was not horribly efficient from a flow standpoint. That's why Jeep dumped it.

I have generally found tape to be ineffective for DD needs.

The reason why is that tape was created for the drag racing world where preventing heat soak from engines running a 4 seconds to 13 seconds was an obstacle to getting more consistent 1/4 mile times. After the tape has comes up to the same temp as the manifold, it becomes a radiator, not a shield, and thus is no longer is effective. In fact, it retains heat in the manifold, which causes the part to remain hot longer after shutdown.

Have you given thought to Ceramic Coatings?

I know there's a million reasons and such on it. I used a dei aluminum foil type heat shield/blanket on my underside of the intake. I ahead a sticky side, I also used hose clamps around the runners just to be safe.
My header, same renix one as you, was coated lightly with 3500* vht. Baked at 200*, repeated slightly thicker at 300*, repeated at 400 & then broiiI left it. Lft it in the oven and just shut it off and. Let it cool slowly. I wrapped mine with die titanium wrap. Soaked wrap, wrapped header, used hose clamps vs stainless zip ties as they are a pain. 3 years now and it still looks like new. I will cut ally be pulling my motor to install a stroker and will see what the manifold looks like. I've had it almost sunk in water, hits every puddle I can. So it gets very wet.

I can feel a noticeable difference in engine bay temp, as well as reaching my hand down by the header. It's no where near as hot as it was before. Your hand within a few 46" before would get very hot, now not so much at all. I'd say it helps quite a bit, but I'm still unsure of the downfalls. 3 years its been wrapped. Ill have it uncovered in the next few weeks.

i have never had heatsoak issues except on the trail (no underhood airflow). heatsoak issue gets worse to the end of the life of the spark plugs. cheap plugs make it better....4.0l's love cheap plugs.


our 2000 has a harder time with it on the trail, the cast iron manifold seems to hold heat better than the tubular manifolds of the past. i just pop the hood when we shut it off for lunch and it fires right up no issues.


its just a jeep thing....i accept that and live with it

Hmm. I just bought some lava wrap from summit and painted my pacesetter renix era headers with the VHT as well after cleaning off the factory paint. I am also wondering how much this will help with under hood temps. Havent installed the headers yet. already welded in a flex fitting and also relocated the tranny lines, trying to solve as many pacesetter issues beforehand as possible.

You could probably make some heat shields out of some cheap multilayer cookie sheets and attach them to the underside of the intake. That would probably help a lot.

jeeperjohn said:

You could probably make some heat shields out of some cheap multilayer cookie sheets and attach them to the underside of the intake. That would probably help a lot.

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galvanized sheet metal would help some, then heatwrap that

I cut a sheet of Thermotec adhesive heat barrier and slipped it in between the exhaust and intake manifolds of my 01 XJ.
http://www.thermotec.com/products/13500-adhesive-backed-heat-barrier.html
It dropped the intake air temps several degrees, when monitored with a ScanGauge and significantly decreased the number of hot soak incidents I has last summer.

Next time the intake manifold is off, I will glue a sheet of insulation to the bottom of it.

lazyxj said:

I cut a sheet of Thermotec adhesive heat barrier and slipped it in between the exhaust and intake manifolds of my 01 XJ.
http://www.thermotec.com/products/13500-adhesive-backed-heat-barrier.html
It dropped the intake air temps several degrees, when monitored with a ScanGauge and significantly decreased the number of hot soak incidents I has last summer.

Next time the intake manifold is off, I will glue a sheet of insulation to the bottom of it.

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That's what I used..but I got it from summit in a certain size. I recommend strapping it to the runner, my glue stuff baked off.
This go around ill be using DEI gold..I like the way it looks

Here's what I did for our rig...

DEI Adhesive backed gold foil to the entire underside of the intake manifold. I cleaned the manifold really good, and simply cut and stuck. It's still working great after several years of turbo heat.





I don't generally reccomend wrapping manifolds simply due to the excessive expansion they will see. The factory manifolds are already known for cracking, and the wrap will simply speed up the process. Just my opinion though. :thumbup:

I did however wrap my downpipe and dump tube simply to protect the surrounding components.

don't generally reccomend wrapping manifolds simply due to the excessive expansion they will see. The factory manifolds are already known for cracking, and the wrap will simply speed up the process. Just my opinion though. :thumbup:
Exactly what I was going to say but eh.. who's going to listen to me.

Boostwerks.com said:

Here's what I did for our rig...

DEI Adhesive backed gold foil to the entire underside of the intake manifold. I cleaned the manifold really good, and simply cut and stuck. It's still working great after several years of turbo heat.

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SICK!!! This is what I'm using on mine this go around. my silver DEI heat shield peeled off, glues still stuck, but the foil came off the adhesive porting. I love the way that stuff looks!!! Looks much easier to wrap the newer manifold lol.

On my stock manifold I wrapped it, on my Thorley no way in hell. However what about the down pipe? Or even right around the cat? I have bedliner & carpet and its still heating the carpet up quite a bit, enough that its warm to the touch over the rest.

Has anyone gotten their intake and/or exhaust manifolds ceramic coated and if so, how much was it and how well did it control temps?

jeeperjohn said:

Has anyone gotten their intake and/or exhaust manifolds ceramic coated and if so, how much was it and how well did it control temps?

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I'd be curious to know as well..