That's fine, I probably get completely different parts coated than you do... I like Swain Tech, but I've also had good results with other companies too. I guess most of those were on parts that don't get used every day though, and some of those were done by coating companies that don't exist in the US (like Zircotec).. I know people who have used other companies coatings for 10 or 12 years with no problems whatsoever. From what I've been told, cast parts are a double edged sword though. They have pretty favorable thermal expansion, but they also have corrosion problems because of what they are (castings have surface porosity). So maybe your manifolds weren't prepped right, and maybe that type of coating or the undercoat doesn't work well for cast parts. Who knows.

I guess what I'm trying to say is that I really haven't had any problems with ceramic coatings, but there are a lot of coatings done by a lot of companies. Those coatings have different application methods (plasma, water born, dip, etc) and different chemistries, with different bond coats and different preparation methods. I'm sure there are probably some horrible types of coatings out there.