Paint Engine

[Dads62]

I purchased a complete LS3 dropout from a junkyard for my project. I pulled the top end to replace the heads and cam but but now I think I want to paint the motor. The motor must have sat outside because the block is oxidized. Do I reassemble it and send it to a paint shop to paint it? Can they clean off the oxidation? Or do I need to send it to a machine shop to have it completely disassembled/cleaned then painted? Do machine shops paint motors?

The motor has less than 10k miles so there is no machine work that needs to be done.

[Bowtie racing]

I have washed one with "aluminium wheel acid cleaner" with dish brush. Then hose it warm water with light pressure.
If you are painting it with rattle can, remember to put correct primer for aluminium first. All machined surfaces like cylinder head ends, should be scuffed lightly so the primer and paint sticks on.

[astroracer]

You can do this yourself. It is a LOT of work if you want the paint to last. If you go at it half-assed the paint will peel and look as bad as the oxidized block.
You need to scrub this thing with tooth brushes, ScotchBrite and Simple Green. Scrub it until it is spotless. THEN wipe it down with lacquer thinner to remove all of the Simple Green. You have to get into ALL of the corners and nooks and crannies otherwise the paint will not stick and it will start to peel out of the crevices. Next wipe it down very well with a good degreaser like Prep-Sol or Pre-Kleeno.
Mask off whatever you don't need painted and spray the engine with a good self-etching primer. DuPont sells it and so does Eastwood.
Once it is primed you can spray whatever paint on it you want. Engines don't get hot enough to required "hi-temp" paint other then on the exhaust ports. Don't worry about those, just paint 'em.
Mark

[Dads62]

Thanks for the feedback.

If I scrub off all the oxidation and not paint it will it come back?

Will the simple green or paint prep chemicals will not hurt the gaskets?

[another69]

If you like the look of raw aluminum (I do), you can use Eagle One "etching mag wheel cleaner". Using engine degreaser 1st, then the wheel cleaner, with a power washer will bring it back to 90% new in my experience. Actually the machined surfaces really will look shiny new. You can always clear coat it if you want. If it peels it won't look as bad. Or just leave it raw.

[raustinss]

You could glass bead it then hot tank and paint away

[Dads62]

I'd rather not take the whole thing apart if possible. I'm worried that some of these chemicals for cleaning/prepping it will hurt the gaskets of an assembled engine.

[astroracer]

Simple Green won't hurt a thing. I use a spray bottle and do small sections at a time. Spray it, let it sit for a couple of minutes then scrub away. ScotchBrite, tooth brushes and the small brass brushes you can get at Harbor freight will work wonders.
It is a lot of work though.
One trick you may want to do is, if you want the raw aluminum look, is to get it clean, then spray it with VHT Brake Caliper paint. I use silver on new and reconditioned intakes and it looks just like cast aluminum! It just doesn't oxide or stain like raw aluminum.
Mark