Tinker's Arc

Chapter 3 of 4

The buggy launched now, and it could run. But Tinker found the next wall fast. He opened the throttle wide down the shed's length three times. Each run, the engine screamed hotter. The flight engine was built to fly through cold air. Bolted into a buggy, it had nowhere to dump that heat. On the fourth run, the metal ticked and stank. Tinker killed it before it seized. He laid a hand on the block and pulled back. It burned. He sat on the floor by the workbench and faced the truth. Full throttle cooked the engine. If it seized at record speed, the whole build was scrap. He needed to move heat off the block faster than the engine made it. Elroy pushed through the door that evening, helmet under his arm. The junior pilot traded flight lessons for Tinker's throttle sense, and he read an engine like a race line. He crouched by the block without a word and held his palm near the metal. "It's throwing heat it can't lose," he said. "Up in the air, the wind strips it off. Down here, nothing moves." He stood. "You need more air on it. Or more water through it." "I don't have a pump big enough," Tinker said. Bam Bam ducked in behind Elroy, a split log still in one hand. The caveman had cleared this shed for Tinker with his bare hands when nobody asked him to. He looked at the hot engine, then at the two of them. "What do you need bent?" he asked. Tinker stared at the block. The answer came to him whole. "Copper line," he said. "Lots of it. We wrap the block in coils and run water through them. More surface. More cooling." He grabbed a pencil. "I need it bent tight and even. By hand." Bam Bam set the log down. "Hard work." They built it that night. Elroy figured the flow and the coil spacing on scrap paper. Tinker cut the copper and fit the fittings. Bam Bam bent each loop around the block, slow and steady, his thick hands making the curves match. The cottony creature bounced along the bench and dropped loose clamps into Tinker's open palm. They tied the coils into a small tank and a hand pump. Tinker rolled the buggy to the wall and climbed in. He fed it full throttle and held it. The engine growled hard. He watched the coils. Water moved through them and came out warm, not boiling. He ran it long, longer than it had ever lasted. The block stayed in his hand's range when he touched it. It didn't seize. He sat back, grinning the way he had at 142. "It holds," he said. Elroy nodded. "It holds here." He looked at the short shed wall. "But you've never run it on a real track. Coils shake loose at speed. You won't know till you open it up on dirt."