He lifted the flashlight to the timing cover and examined the old fasteners. Walter Steel's engine was not an ordinary factory arrangement, a fact the specialists had documented without following it to its consequences. The custom cam drive incorporated a small chain-driven conversion and a manually indexed adjustment that earlier mechanics had exposed but not understood. Owen recognized the construction from a chapter in an obscure rebuild manual, then checked the physical evidence against the drawing he carried in his memory.
Somewhere above him a man yelled, "He's touching it like it's going to talk back."
Owen did not look up. He heard Thomas's voice instead, the deep familiar voice that had lived in his head for four years. Listen before you touch. The engine tells you everything. As a boy, he had sometimes wondered whether his father had meant it literally. Now he understood that the phrase was a rule about humility: before deciding what a machine needed, you had to accept what it was already showing you.
He moved the first fastener carefully. It came free without resistance because Nolan had loosened the area while checking another component. The next one followed. Owen caught both in his palm and placed them on the folded edge of his work shirt, protecting them from grit. Behind him Garrett mocked the way he handled the hardware, suggesting the boy was preparing a museum exhibit rather than a repair.
Owen raised the cover far enough to see the custom drive. He did not fully remove the assembly; doing that would have exhausted the entire time allowance and created more opportunity for damage. He used the flashlight to find two alignment marks that had been placed by whoever first built the conversion. One was bright where a tool had recently touched it. The other sat two sprocket positions away from where it belonged.
"There," he murmured.
He did not claim the drive could have operated indefinitely out of phase. Something had shifted abruptly during the last miles on Interstate 94, creating the metal note he heard as the engine turned. The timing error was small enough that the assembly had not destroyed itself, but large enough to disrupt the sequence required for combustion. He remembered a salvage-yard motorcycle with a similar aftermarket arrangement and the long afternoon it had taken Thomas to teach him what an apparently minor misalignment could do.
The old Craftsman sat perfectly in his hand. Owen adjusted the mechanism back to its marks, checked the tension and seating, then returned the cover to its position. He worked quickly, but he checked twice before tightening. At the edge of his vision the stopwatch continued counting toward failure.
"One," he said. "Cam timing was out of position. Two marks didn't line up. They do now."