If the engine is out of the vehicle, there's a simple trick that has allowed me to store engines for long periods of time with no deterioration. Drain as much oil out of the crankcase as will flow out in a few minutes, then replace the oil pan plug and turn the engine upside down. The residual oil in the crankcase will run into the cylinders, and keep the rings and combustion chambers oil-sealed for years. A wrecking yard across the street from my shop in California stored their take-out engines that way, and other than lots of smoke on the first startup, they never had any storage issues.
Jerry