I personally don't think much of do-it-yourself engine painting.
You may be able to procure pre-colored (factory) bits & pieces, which have been anodized or powder coated. These have been done with paints / coatings tested specifically for the temperatures present in your engine bay.
For example, you may get an anodized intake pipe for your high-velocity aftermarket intake filter. The paint / coating / anodization would have been tested to ensure that it would not peel / crack under normal running of your vehicle. Simply slathering paint onto a pipe would do you no good whatsoever, as (from personal experience
) I have found that the paint simply flakes off.
The same goes for the tappet cover painting. If you can manage to find the specialized paint, it should work for you, but remember that
theoretically, it may lead to higher temperatures due to the different heat conduction properties of the paint compounds.
So,
to answer your question, if you think you have a good paint / coating & the requisite experience & knowledge to go around making your engine bay your coloring book, please do so by all means.
Methinks you should also take the opinion of
Viper,
Arush,
Ported_Head,
Nitroxx, & other guys that may have done this before.
Ciao!
_________________________________
& for the morons... in case you didn't get it, I was kidding in the earlier posts... So don't come after me if you nuts actually do what I was kidding about.