I would never ever bead or sand blast an internal engine component, and for sure not an aluminum one, the inside of an intake counts. Even if you only blast the outside there will be some that find there way to the inside, and eventually in to the engine.
You may think you can clean all the little bits out, but you can't. They get stuck in the metal and with the heat cycles they work their way out.
I worked on an all aluminum V16 engine that was rebuilt by a "professional" shop. When I had the head off to replace a blown gasket I found about a spoon full of glass beads in little piles where oil had settled. The "rebuilder" had glass beaded the block and heads, and while they looked great on the outside it was ruining the inside.
To clean aluminum parts, or any engine parts I will use walnut hull blasting media in a dedicated blast cabinet that has never had anything but walnuts from new, and never a part that was blasted in the glass bead cabinet first. The walnuts are softer, don't remove much if any metal, don't tend to get stuck in the pores of the metal, and if they do end up in the engine they do less damage than sand or glass beads.
The aluminum cleaning acid and a fine plastic or stainless brush should work well too.
Grigg
