On March 31, 2001, about 1133 hours Pacific standard time, a Stinson 108-1, N8158K, experienced a total loss of engine power during cruise flight. The pilot made a forced landing about 1.5 miles north-northeast of the Redlands Municipal Airport, Redlands, California. During the landing rollout, the airplane collided with a dirt berm. The airplane was substantially damaged, and the private pilot was seriously injured. The personal flight was performed under 14 CFR Part 91. Visual meteorological conditions prevailed, and no flight plan was filed. The flight originated from Banning about 1120. The pilot reported to the National Transportation Safety Board investigator that he had purchased the airplane a few weeks prior to the accident flight, and he was familiar with its operation. Prior to taking off on the accident flight, both of the wing fuel tanks had been filled. The pilot also stated that no vibration was felt prior to the loss of engine power. In an attempt at restoring power, he applied the carburetor heat, changed the mixture setting, and repositioned the ignition key. However, none of his actions were successful in restoring power to his airplane's engine. Thereafter, he made a forced landing on the underlying rough terrain. A deputy sheriff responded to the accident site. The sheriff reported to the Safety Board investigator that upon arrival he observed fuel streaming from the wing tanks of the impact-damaged airplane. The airplane was manufactured in 1946. The airplane was subsequently recovered, inspected, and partially repaired by a Federal Aviation Administration certificated airframe and powerplant mechanic. The mechanic who performed the work verbally reported to the Safety Board investigator that the engine was completely torn down. No evidence of any preimpact malfunction was noted. The accessories were also examined, and no evidence of malfunction was noted. Both the carburetor finger screen and the gascolator fuel screen were observed clear. The magnetos were functional. The carburetor heat control worked. One of the propeller blades was noted bent in an aft direction indicating the crankshaft was not rotating during the impact sequence. The mechanic indicated that he could not ascertain the reason for the non-mechanical total loss of engine power.