I decided to wrap my exhaust from the pack nut to the muffler with high temp header wrap to keep the heat down in my T. However, after it gets hot the wrap starts smoking and smells pretty bad. I can also see that the wrap is turning kind of brown. Is this normal?
Yes. The wrap will smoke pretty bad for a few minutes. Mine turned from black to a light gray color. Once it burns off it becomes very brittle and will break off pieces if you bump it with anything.
After the stink goes away, your passengers will love it!
My black Autozone wrap gave off a funny smell then turned grey when heated. It did not get brittle. In fact I reused part of it when I changed the motor.
Best header wraps are made from basalt fiber; see:
Plus you can tell people you have your exhaust wrapped in lava..."just how Henry would have wanted it to be."
I purchased what is called 'Header Wrap'. The hot rodders use this stuff and it is pretty good quality. Mine is four years old and has not failed yet. I got it at Speedway Motors, it was about $50, but worth it. The reason I use it that while touring during the summer, the inside of my TuDor gets rather hot. This wrap has reduced the inside temperature from blazing to tolerable. Mike