This is also posted in the Product Review section but I was hoping I might get additional responses over here....
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I'm wondering if anyone here knows the properties of header-wrap.... I'm far too lazy to remove and wrap my headers (not to mention they're equal-length shorties, which would take a long time to do)....so I'd rather wrap all of my intake tubing and my MAF sensor to keep the heat out. Now I know header-wrap will keep a LOT of heat confined to the headers...but does it also block out heat? I basically just want to know if I can use it as an effective intake shield.

 

Yes it definately slows heat transfer WAY down. That means you can use it on about anything to slow the heat transfer. Layering materials also helps. Any time you add different layers of materials you slow down heat transfer.

 

but once your intake does heat up, it will take forever to cool down. and alot of heat wil come internaly from the engine. you probably wont notice much of a difference. in my opinion.

 

exactly.


i would expect the intake manifold to become HOTTER doing that.. not cooler.

 

It doesn't work that way. It is possible for intake ducting to get heat soaked, but since the air is moving through it when the engine is running it drops back down quickly and stays much lower due to slower heat transfer. Besides you'd get much worse heat-soak (and quicker) without insulation. I have tested this very thoroughly.

Non-insulated advantage over insulated only becomes a factor after when you've turned the engine off hot for very long periods of time (in the hours) where the non-insulated will cool down quicker while just sitting there due to more surface exposure to cool air. As soon as you start the engine again this advantage is gone and the intake air temp drops again to near equal that of a dead-cold intake duct. The insulated duct has the huge advantage of keeping the temps lower over the long-haul and when the engine is running where it counts.

I use a thermocouple to measure air temp right before my throttle body. At steady cruise my intake air will stay right at or within 2*F of ambient temp. After 1/2 hr of stop-n-go it only goes up around 5*F over ambient, but quickly drops to ambient at WOT or after some cruising.
The total amount of heat getting to the intake air is much much lower than a non-insulated air duct.
My thermocouple sensor wire has been in my air duct for approx 2-years so I have watched it under many different conditions.

 

im talking about the intake manifold, not the air duct... id agree on wrapping the air duct.

but the intake manifold has a hot engine under it, warm oil splashing under it, hot coolent flowing thru it, ect.... theres a decient amount of heat thats released into the air thru the manifold..... *shrug*


a nice ceramic coating on the INSIDE of the runners couldnt hurt though...


btw, in general, im refering to carb style intakes, because i work with thoes alot more often then anything else.

 

That's true.
Oil-shield, blocked EGR ports, and lower coolant temps all help keep the intake cooler.

I thought he was talking about the air ducting before the TB.

 

I was.. But thanks for the input guys. I'll be employing that heat wrap sooner or later...