The pilot reported that about 30 minutes into the local flight, he heard some crackling in the radio reception and then the cockpit flight displays went blank. The engine stumbled and lost power completely. The pilot was operating the airplane in the airport traffic pattern at that time and decided to secure the engine to set up for a forced landing to the runway. Smoke began entering the cockpit during the landing flare, and then the pilot noticed flames on the right side of the airplane. After he stopped the airplane, he exited, obtained a fire extinguisher, and called the fire department. The airplane sustained substantial fire damage to the fuselage, empennage, and engine mounts. A postaccident examination revealed extensive thermal damage to the engine and within the engine compartment. The damage extended into the cockpit and cabin area, and then along the right side to the aft fuselage. While clear that the fire started within the engine compartment, the extent of the damage prevented a determination of the exact location and source of the fire.