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Heat wrapping stock manifold?

Renegade XJ

NAXJA Forum User
Location
corona ca
I'm in the process of replacing my manifold gasket, my stock manifold has no cracks and being that it's a Renix 4.0 there a basically no aftermarket options for it so I'm just gonna put it back on. I figured I would heat wrap it to try and help reduce under hood temps a bit.

Any thoughts in doing this to a stock manifold? I'm worried that the stock manifold material might be too thin and heat warping it might cause it to crack easier due to it being under more heat light this.
 
I considered the same thing on my APR header when I installed it. The wrap will accelerate rust and it will need to be replaced sooner, but it's your ride, your call.

Better options are to put a heat shield/heat wrap between in the intake and the exhaust. Also, install hood vents and take care that they don't leak on any important electronics.
 
I don't really know what causes the cracks, repeated heat and cool down cycles, the metal hardening with age or maybe quick quenching when you drive through a puddle. Maybe all of the above.

The stock manifold is a blended steel and has a lot of nickle (a guess) in the blend. I've welded a lot of metals over the years and noticed it acted a lot like a stainless steel when welding on it, it has some soft non ferrous components blended in. I call it almost stainless

I've also suspected that stressing the exhaust system after the header may play a part. I'm always pretty careful about how I tighten the exhaust joints down after muffler (or Cat) replacement. And always loosen the the two bolt flange between the header and the down pipe to stress relieve the header section during muffler and pipe work. I also avoid using a BFH or brute force taking exhaust pieces off, I try to remember the exhaust is connected to the manifold while trying to get that stubborn muffler, Cat or tail pipe off.

Wrapping may help protect from quick quenching the header when driving through a puddle. Renix rarely have any vapor lock issues in the fuel rail like later model non return line models have, so this wouldn't be an issue.

I'm with Jonner on this one.
 
A heat resistant blanket is the best thing you can do. As others havestated, wrapwill only make things worse in time.
 
wrapping on the stock manifold probably won't help all that much. You'll trap moisture when not in use, and oils / grease from any leaks (read: fire hazard). You'd be better off looking at the heat shields and making sure you have a functional air-dam on the front as that creates a low pressure zone under the vehicle, which helps suck hot air out of the engine bay as you drive.
 
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