I've been watching Pete's Garage on YouTube and the guy is absolutely amazing and very enlightening on the subject. He has at least one video on engine painting but he mentions it in a number of other videos. However, he doesn't really expound on why an engine should be painted. What are the benefits of painting an engine? For example, my Tacoma has an aluminum block and aluminum heads but they are not painted. Why are some other engines painted?

I've been watching Pete's Garage on YouTube and the guy is absolutely amazing and very enlightening on the subject. He has at least one video on engine painting but he mentions it in a number of other videos.

However, he doesn't really expound on why an engine should be painted. What are the benefits of painting an engine? For example, my Tacoma has an aluminum block and aluminum heads but they are not painted. Why are some other engines painted?