Pre-oiling an engine rebuild
 

If my longblock is complete (including oil cooler) is there any reason I couldn't put a couple of quarts of oil in the engine, loop the oil lines together, attached the trans with starter and "bleed" the oil system by turning over the engine? To confirm flow I could remove the sensors and various plugs (i.e. pressure relief pistons)? Anybody ever do this?

If you lubed parts during assembly I would not go to the trouble. On initial start up pull the coil wire and crank until you get oil pressure. That said I see no reason you couldn't try your method. I don't think it will accomplish anything that pre start per above would not do.

Overkill.

Shoepop has it right.

With engine in car and ready to go, crack one of the cam oil lines, put a rag under the fitting, and when some oil comes out you are ready to start the engine as you have oil in the places which need it most. Leave the spark plugs out, and the engine will spin faster while doing this. Won't take long.

Of course, if you didn't lube things while assembling the engine, - - -

Walt

One reason assembly lube is thick is so it will stay where you put it if the motor is stored a while between assembly first startup.

Spin it on the starter motor with the plugs out to get oil pressure.
Rather than remove the cam tower oil line I like to spin the motor on the starter motor while the nuts are off a totally clean and dry rocker cover but it's in place on the studs.

Then after spinning the motor on the starter for few seconds with oil pressure, lift off a valve cover and look to see that there is an equal amount of fresh clean oil shot up on the inner surface of the covers in all 3 spots from the cam spray bars.

Now you know the spray bars are clear and shooting oil and there is no mess to clean up.