I´ve always done it with the engine turned off. Can´t see what the advantage would be trying to get your fingers caught and everything rocking up and down
. First engine I ever did was a Triumph straight six out of an old Vitesse. 1600 cc. Family friends who had a garage showed me how to do it. And the valves etc, etc. Was told to do them warm, engine off, and then run the engine for 10 mins and then test them again. Renovated the engine and it ran very well afterwards (tin worm got it in the end
)
Done quite a few Volvo motors, B4B, B16, B18 and B20 (all push rod)
Would be fun to see someone do them with the engine running
Still maybe as good as Colins fan belt change
