If you've read the first part of the Exhaust Manifold Restoration saga, you'll know that after a lot of effort, I still had a pair of raw, rough looking cast iron manifolds. After researching my options online, I decided to go with ceramic coating. I took the manifolds to Hi Octane Performance Coatings (who seem to be the go-to people for ceramic coating in Sydney) and a week later I collected my freshly coated manifolds.
You can see the results below. When freshly coated the manifolds are black, but Hi Octane Performance Coatings told me they would go grey after a few heat cycles — this proved to be correct. The final colour is a good match for cast iron I think, with a nice matt finish.
I was very impressed with how well the castings came up after being media blasted. The casting numbers a now clear and sharp. The other benefit of ceramic coating is that the inside of the manifolds look as good as the outside, with full coverage over every surface.
I've been running the car with the coated manifolds for over a year now, and I'm convinced the ceramic coating has reduced under-bonnet temperatures. I also think it has helped reduce fuel percolation, which was an occasional annoyance when restarting the car. The coating is also very tough, with no evidence of chipping, flaking or discolouration. The dark grey colour has also remained unchanged.