On May 16, 1999, about 0740 eastern daylight time, a homebuilt Titan Tornado, N194PA, was substantially damaged during a forced landing and collision with terrain in Monroe, Connecticut. The certificated private pilot was seriously injured. Visual meteorological conditions prevailed and no flight plan had been filed for the flight that departed the Twin Pine Airport, Pennington, New Jersey, about 0630, destined for the Waterbury-Oxford Airport, Oxford, Connecticut. The personal flight was conducted under 14 CFR Part 91. The airplane was owned and built by the pilot. In a written statement, the pilot said he was flying at 1,500 feet above the ground, when the airplane's engine "missed" once and then lost total power. The pilot stated the airplane was too low to attempt a restart, and he established a glide for landing. During the forced landing, the airplane's left wing contacted the ground and the airplane nosed over. Examination of the wreckage by a Federal Aviation Administration (FAA) Inspector, revealed metallic particles inside the engine's crankcase. The engine was retained for further examination. The engine was reexamined on May 26, 1999, by an NTSB Investigator, the FAA Inspector, and a representative of the engine manufacturer. The examination revealed that the mag cylinder connecting rod bearing had failed. Additionally, the 2 cycle Rotax 583 engine had been manufactured as a snowmobile engine.