[dad911]

I think the answer depends on the particular engine, and why?

I once ran a carburated v8 by just supplying gas (gravity feed) and 12 volts to the starter and ignition.

A Dry-sump engine such as an early 911 would need an oiling system in place also. A later 3.2 or 3.6 would need computer, wiring harness, etc. and would probably not be worth the trouble. It may be easier to just spend the few hours necessary to bolt it into a car.

Why would you want to do this? If you are purchasing an engine out of the car, more information about its condition could be had by testing. I would do a compression & leakdown test, pull the valve covers, and look at the drainplug etc.