Aircraft reciprocating engine indentification?
All certified airworthy aircraft engines have data plates attached that gives all the identifying info. If the plate is missing, the engine is not legally airworthy no matter what the actual condition.
A 'reciprocating engine' is just another name for a piston engine as opposed to a jet. Technically, the engine works just like the one in your car, with a piston moving in and out of a cylinder. The difference may be that the aircraft engine may have it's cylinders arranged in a circle ( radial engine) but the action is just the same.
The largest single engine propeller driven aircraft is the Grumman AF-2S Guardian, a sub chaser of the Korean War era. It grossed at 25,500 lbs and was powered by a Pratt & Whitney R2800 engine of 2400 horsepower. It also had the largest Wing span for a single engine reciprocating aircraft at 60' 8".