Long ago, the engine actually came off a small plane like a Cub Coup or something, the pilot was quick to put the nose almost straight down so he would have airspeed, controls, , etc. to keep from just falling like a leaf & he got on the ground without dieing. Back in the 30’s maybe. Have seen it referenced some back in the day.
Know personally, I have flown the plane actually, of a PT-22 with a Kinner 5 cyl that was on the way to Oshkosh & threw a full ½ of it’s wooden blade. Ripped the engine off but it hung between the gear legs by the magneto ‘P’ leads. Ended up inverted in a corn field due to some great flying. The wife, the passenger, cut he head when she opened her harness and fell out & hit her head on something & got a small cut. No other injuries except to the aircraft.
I know of some light twins that literally lost an engine but of course they are not a single engine.
Prolly some more that were never recorded back in the real old days but not many where the whole engine came off the airplane completely. They were probably mostly fatal & maybe no one actually figured or cared as to the actual cause.
I would think that some came off ( blown off, etc. ) single engine aircraft during the wars where propeller driven single engine aircraft were used. All kinds of weird things happened during those.
You have better Google-Fu than I do so… ?