I'm assembling my 3.5 out of my LHS. Been wondering....what is the point of the exhaust manifold heat shields? It sounds like a dumb question. But I've been wondering cause there is a shield on both the top and the bottom of each manifold. So the manifolds are inside this pocket of metal. To me this design seems to trap the heat inside the shields. It has to go somewhere. I can see the logic of a heat shield on one side but not completely encasing the hot manifold. Is this more of a cosmetic thing?

 

Yeah, it's purely cosmetic. You see when the hot exhaust pipe comes in contact with tall grass or dry leaves that you might have parked over, and they catch fire and burn the car up, it really makes the car look ugly. Purely cosmetic.
Likewise, if the heat from the exhaust melts the insulation on a wiring harness and it shorts out and causes a car fire, again, that makes for a really ugly car, not to mention the ugly plume of black smoke visible for miles around. Purely cosmetic.

[Warning: This post contains sarcasm.]

 

You're a funny guy. I get what you're saying though.