Doing a little light reading, and i've come across the term metal fatigue a few different times. Has anyone actually had this happen to them, or know anyone who has? Was it on a race vehicle or daily driver, etc...

Reason I ask is that i'll be getting a catless downpipe and i was thinking about doing a ceramic coating on the outside. I know there are pricey options like swaintech to go with, that do both inside and out...but this isn't going to be used in a racing application, it's just hot in PHX and i'd like to keep any extra heat out of the engine bay.

Saw a few write ups on using cerkote that seemed pretty easy. I know it won't be as good as jot-hot or swaintech, but it's a fraction of the cost, and some of the results were pretty impressive in regards to radiant heat.

 

I use Cerakote on heads in the intake ports of dry runner engine. Aka, direct injection. Also on the exhaust ports, combustion chambers, intake valves and exhaust valves. It's actually pretty durable in these applications. Outside of a down pipe I'm not sure about. Does it help, yup !! Sure does. I do it mostly when I do hi-end port work for race cars. Also use there piston micro slick. It all helps alittle. And when you add alittle here alittle there it creates 1 big package. It's that package you gotta shoot for. When that's achieved there is a bit of longevity that's had. As well as performance. I use coatings on my entire motor. It's fast when it get stepped to the floor.
Now, if you go out and romp on it every day, it's only gonna last just like a race motor. That's why they are rebuilt at the end of the year. They only last for so long. But the initial gains are definitely higher than normal. For what your doing, I wouldn't worry about is my opinion.

 

It only cost me $50 to ceramic coat, inside and out. Looks great and it does work and helps keep under hood temps down.