No, we test airplanes at TDC for leak down. The timing is a set thing at what ever degree the engine operates at for testing.
All the A&P that tested my airpalne motor while I watch the leak down tests did it the way I describe, the same answer on the I-A when I ask them about the proper leakdown test
I did end up marking the starter ring gear so I knew where all six cylinders should be at TDC and I did test my 260 HP O-540 Lycoming motor at TDC
Those tapered rings seemed to sealed better down lower though
No more hijacking, I'm done
