Properly painting the short block

I mask off gasket surfaces with blue painter's tape. 3M seems to be one of the better tapes. The trick i use it to trim the tape using a medium to fine rat tail file that is gently run with a downward stroke along the edges. It pushes the tape down at the edge and cleanly cuts it. I have also used the knurled handle of a cheap ratchet wrench with similar results.

Prep for me involves cleaning the block using the water rinse-able purple cleaner, a good medium stiff brush and medium course scuffing pads. I follow that up on the dry parts with a lint free cloth and lacquer thinner or brake cleaner (sometimes with a tooth brush like scrub brush and wipe with a cloth). All surfaces need to be oil free.

I then spray the parts with VHT engine enamel using multiple medium tack coats followed with 1 or 2 full wet coats. I do let the paint dry for 15 to 20 minutes between coats, longer if it is colder out. There are minimum temperature requirements listed on the can. It is nothing short of amazing in appearance and longevity, and I have yet to have any adhesion issues with aluminum parts.

I always paint aluminum heads too, but I understand those who like to see them clear coated or raw.