[Marty Levenson]

If you want to get serious about priming use yellow zinc oxide (aka "cold galvanizing").

Degrease with solvent, immediately spray with brake cleaner, dry only with compressed air. Do not touch the metal with fingers or rag. Spray several coats of yellow zinc oxide (spray bomb). Overcoat with desired engine paint.

Overalls, heavy rubber gloves, and full face mask + good ventilation. Do not skimp on safety.