If the engine is on fire, you probably wouldn't see it as the air flow takes it under the aircraft.
On a stalling exercise i could see the prop was trying to stop every time we pulled the throttle to idle.
Then the engine lost some power when throttle pushed forward, so above a inversion we began to head back to the airfield.
Power slowly regained as we descended so thought it was a mixture problem.
Joined overhead then landed, as the aircraft rolled out the engine stopped but managed to turn off the runway. Bit annoyed with it stopping, i restarted it, then noticed grey smoke coming from the cowling. So evacuated the aircraft with extinguisher and fired into the engine cooling intakes. Later people commented about the four foot odd flames under the aircraft. Turned out to be a faulty carb. flooding. Was AD that hadn't yet been complied with.
I remember my old ex BoB instructor asking what i would do with an engine fire. He said you should pull back to the stall to stop the prop. before descending to stop fuel and oil being pumped out. Said he had seen many aircraft burn up by the pilot trying to blow the flames out. RIP Mike Edwards.
Also when dealing with an emergency, try to get someone else to do the navigation by asking ATC for QDM or radar vectors.
When i was above the haze, the ADF wasn't working and too much time was being used trying to twiddle VOR instead of dealing with the engine problem. The CAA in their wisdom have decided our airfield VDF not fit so can't be used. Shame worked very well for the last 20 years. Another safety item removed by the safety regulator.