Is in a heated or non-heated storage space? Is that space subject to temperature swings? Why do I ask? Temperature swings tend to induce condensation. Condensation is bad. If it's on an engine stand and in a constant temperature storage space, the heavy oil wrapped in a well sealed bag method should work. Further, you could drop a couple moisture bags in the bottom of the bag below the engine to collect humidity. No matter your method you should probably open the bag every 6 months or so and make sure all is still good. But if it is in a tightly sealed it should stay good for quite a while.
Use a big heavy wall contractor bag. Seal it as tight as you can. Don't use WD40. I have read it actually evaporates and stops protecting over time.
There are spray oils and other products you can wipe on. I like ATF. ATF does not evaporate it seems. Wipe it all down, bag (or double bag) it, and seal it up as tight as you can. Store it in a temperature controlled place for best results.
I have a stored 5.0 HO camshaft in a PVC tube in a bath of virgin ATF. Seems to be working. I keep it in my basement where it is always almost the same temperature and the space is humidity stable.
STA-BIL makes a fogging oil that would probably be perfect for this task. Spray it. Bag it. Seal it tight.