Does anybody know roughly how hot the exhaust manifold gets. I have a can of engine enamel that is good for 2000 degrees and wanted to know if it's ok to use on it.
Mike, your manifolds will never get anywhere close to that temp, you're good to go.
But as a suggestion, they do make many paints and coatings especially made for exhaust manifolds..something to consider.
Depends on how bad your engine is running but 2000 degree paint will probably stay on as long as the color doesn't approach yellow. These types of paint usually contain a ceramic powder that needs to be independently cured as well as burning off the carrier. Simply spraying the coating and running the engine normally doesn't work. Also, the base metal needs to spotlessly clean. Spraying the paint over rust will cause it to flake off.
I would guess that 1200 to 1300° would be about the max for a manifold.
Here is a color/temperature chart:
Growing up in the '60's and driving a T, I often found myself without a lighter. It was pretty common for me to pull to the side of the road, full retard the spark and light a cigarette off the manifold. I gave up smoking in the '70's but still have that lighter in a shed in the back. I don't recommend it, but retard the spark at night and you can see the beating the manifold takes.