Historic/Vintage aircraft should not be ground run unless for a specific purpose i.e return to flying status…
They should be properly inhibited and stored in a low humidity envoirnment if at all possible..
Ground runnig of a/c in short term storage can be acceptable provided the engine is run to normal operating temperature..
Short runs can be disasterous in the long term due to build up of moisture and other contaminants which would boil off at higher temps..
As regards running an engine without a propeller or other vibration dampening device fitted..the mind boggles!!!!

Finally if you want to preserve an engine inhibit it..
If you dont care and want noise,well run away!