Compression testing with engine out of car
 

Hey everybody, hoping somebody can help me.

I blew my engine recently, got a new-to-me junkyard engine (longblock). It was claimed to be compression tested, and in good functioning order but when I received it, the block was covered in rust. Alternator, water pump, wiring harness mount, etc. I don't have any good feelings about putting this engine into my car because of that, so I was wondering if there were any good ways to do a compression test while the engine was not in the car. I don't want to go through the effort of putting the engine in, THEN doing a compression test just to find it's a bad engine too.

Problem is you need to have the engine warm while you're performing the test to get an accurate/reliable result.
I've tested a motor outside of the car to observe the waveforms and see if there was a noticeable difference between the three faces (indicating a possible bad seal), but this was because the car was wrecked and obviously we couldn't just start the engine... it was the best thing we could do besides installing it in another car and trying it.