Who has painted their engine with a spray gun?

I am by no means an expert, but I have been painting for about 40 years. This is how I do it. Maybe some overkill!
1. There is no such thing as TOO CLEAN! Specially with engines. Protect the engine from water getting inside places you would not want, then clean it thoroughly. I have always just used an assortment of brushes with hot soapy water. Get down in every nook and cranny. When it is absolutely clean, blow as much water off as possible, and towel dry the rest.
2. You DO need to spray some primer on it. Like @abodyjoe I like to use epoxy primer. Spray two coats of epoxy primer AFTER wiping the engine down with your favorite brand of pre-paint solvent (I really like Pre from Eastwood) and blowing it off to get rid of any dust. Follow the directions for your brand of epoxy for how long until it can be sanded. Then I scuff the engine with a green scuff pad for good mechanical adhesion. Make sure you get in every nook and cranny. Wipe the engine down with pre-paint solvent and blow it off. Now you are ready for paint.
3. Masking is the same as for using rattle cans. I REALLY like the 2K engine paints from Eastwood. They spray on beautifully, and they dry so shiny, you honestly can't tell when they are dry. I use my Devilbiss primer gun with a 1.5 tip. I spray on one light tack coat followed by two wet coats. I sprayed my 340 about 8 years ago and it still looks great.
#NO RATTLE CANS.